Note: Descriptions are shown in the official language in which they were submitted.
CA 02285007 1999-09-22
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METHOD FOR PRODUCING SHAPED BODIES
FOR LITHIUM ION BATTERIES
The present invention relates to a method for the production of molded
articles
suitable, inter alia, as solid electrolytes, separators and electrodes for
electro-
chemical cells, and preferably of sheet-type molded articles for
electrochemical cells
by melt extrusion; solid electrolytes, separators, electrodes, sensors,
electrochromic
~'~dows, displays, capacitors and ion-conducting foils per se which, in each
case,
comprise such a molded article; and electrochemical cells comprising such
solid
electrolytes, separators andlor electrodes.
Electrochemical cells, in particular rechargeable ones, are generally known,
for
example from "Ullmann's Encyclopedia of Industrial Chemistry", 5th edition,
Vol.
A3, VCH Verlagsgesellschaft mbH, Weinheim, 1985, pp. 343-397.
Among these cells, a special position is occupied by lithium batteries and
lithium ion
batteries, in particular as secondary cells, owing to their high specific
energy storage
2 0 density.
As described inter alia in the above quotation from "Ullmann", such cells
include, in
the cathode, mixed oxides containing lithium ions and ions of manganese, of
cobalt,
of vanadium or of nickel, such mixed oxides being suitably described, in the
stoichiometrically simplest case, as LiMn204, LiCoOZ, LiV205 or LiNi02.
These mixed oxides react reversibly with compounds which are able to
intercalate
lithium ions into their lattice, for example graphite, the lithium ions being
removed
from the crystal lattice and the metal ions such as manganese ions, cobalt
ions or
3 0 nickel ions in this lattice being oxidized in the process. This reaction
can be utilized
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in an electrochemical cell for storing electrical energy by the compound which
takes
up the lithium ions, in other words the anode material, and the lithium-
containing
mixed oxide, in other words the cathode material, being separated by an
electrolyte
for which the lithium ions migrate from the mixed oxide into the anode
material
(charging operation).
In so doing, the compounds suitable for storing lithium ions reversibly are
usually
fixed on collector electrodes by means of a binder.
1o When the cell is charged, electrons flow through an external voltage source
and
lithium cations through the electrolyte towards the anode material. When the
cell is
utilized, the lithium cations flow through the electrolyte, whereas the
electrons flow
through a load from the anode material to the mixed oxide (cathode material).
So as to avoid a short circuit within the electrochemical cell, inbetween the
two
electrodes there is an electrically insulating, but lithium cation-permeable
layer, a
solid electrode or separator.
As is known, solid electrolytes and separators consist of a support material
into
2o which a dissociable compound containing lithium cations is incorporated to
enhance
the lithium ion conductivity, as are, normally, further additives such as
solvents.
In this context a solid electrolyte is understood to be a material which can
either be
used without a solvent in the electrochemical cells or which, in the case of a
solvent
being used, largely contains the latter in physically bound form.
To prepare the solid electrolytes or separators, the general approach is to
apply a
solution from the support material, the compound containing lithium canons
and, if
required, further additives to a support, and the solvent is then evaporated.
One support material, proposed e.g. by US S 540 741 and US S 478 668, is a
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copolymer from vinylidene difluoride and hexafluoropropene.
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Production of these battery foils in accordance with the above publications
involves
dispersing the solid, plasticizer and binder (see Table).
Anode Cathode Separator
Solid Graphite LiMnzOa Aerosil
PlasticizerDibutyl phthalateDibutyl phthalateDibutyl phthalate
Binder COPO COPO COPO
(PVDF/HFP) (PVDF/H~P) (PVDF/HFP)
Solvent Acetone Acetone Acetone
ExtractantDiethyl ether Diethyl ether Diethyl ether
~
The dispersion is then cast, and the filin is dried. Then the plasticizer is
extracted
with diethyl ether. The binder is a random copolymer of vinylidene fluoride
and
hexafluoropropene (8-25%).
The method described there has the following drawbacks:
1. Use of organic solvents
2. Film has to be dried
3. Extraction of the plasticizer is required
4. The extractant is explosive
5. Extraction of plasticizer from the sheet is not 100% effective.
Also known are solid electrolytes on the basis of poly-(alkylene oxides);
these solid
electrolytes are described e.g. in EP-A 559 317, EP-A 576 686, EP-A 537 930,
EP-
A 585 072 and US 5' 279 910. The polyethers described there are modified at
the end
" CA 02285007 1999-09-22
4
groups or func-
tional groups, e.g. by (meth)acryloyl groups, and are cross-linked, prior to
being
used as a solid electrolyte, by means of energy input (heat, light).
Additionally they
generally contain a conducting salt, e.g. LiPF6, to improve their
conductivity. The
methods for producing the systems described there include conventional
casting,
laminating and compression-molding processes.
US 5 348 824 relates to a method for coating a positive electrode of an Li
battery by
melt extrusion of a solid polymer electrolyte which comprises a polymer as
defined
therein and an Li salt. EP-B 145 498 likewise describes a method for producing
molded articles suitable for electrochemical cells, which involves melt-
blending of a
mixture of a conducting salt, an organic polymer and a plasticizer and
producing a
sheet from the melt, e.g. by extrusion. The electrochemical load-carrying
capacity of
the sheets thus obtained is inadequate, as a rule.
All these methods have in common that they are very complicated and/or result
in
molded articles which are unsatisfactory in terms of resistance to pressure
and/or
thermal stability.
It is therefore an object of the present invention to provide an improved
method for
producing such molded articles and to provide these molded articles per se
which,
owing to the production process, have a special microstructure and improved
mechanical characteristics.
Owing to, in particular, the presence of a pigment III and the special process
parameters used here, as defined hereinafter, molded articles are obtained
which,
when used as a solid electrolyte, separator or electrode, exhibit improved
short-
circuit withstand capability, enhanced resistance to pressure, in particular
at elevated
temperatures of above 120°C, and a greater porosity, all compared with
the systems
known hitherto, and in addition are capable of lasting suppression of Li
dendrite
formation. Furthermore, the presence of the pigment accounts for improved
cycle
AMENDED SHEET
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stability and a higher current rating of an electrochemical cell. Another
point is that
if the preferentially used basic solids IIIa are employed, the acid formed
during
preparation of an electrochemical cell is scavenged or neutralized.
The invention therefore relates to a method for producing a molded article,
prefer-
ably a sheet-type molded article, which method comprises the following stage:
I) Compounding and melt extrusion of a mixture I which comprises a blend II
which contains:
a) from 1 to 95 wt% of at least one pigment III having a primary particle size
of from S nm to 20 mm which is selected from the group consisting of an
electrochemically inert solid IZIa, a compomd IIIb which during charging
is able to give off lithium ions, and a compound IIIc which during
charging is able to take up lithium ions, and a mixture of the solid IIIa
with the compound ITIb or the compound ITIc,
b) from 5 to 99 wt% of at least one polymeric binder N, and
2o c) from 0 to 200 wt%, based on the total amount of the components a) and
b), of at Least one plasticizes V,
wherein the proportion by weight of the blend II in the mixture I is from 1 to
100
wt%, and
wherein mixtures I comprising blends II containing, as the polymeric binder N,
a
copolymer of vinylidene fluoride (VdF) and hexafluoropropylene (I~'P) having
an
HFP content of from 8 to 25 wt% and, as the plasticizes V, a compound selected
from the group consisting of dibutyl phthalate, dimethyl phthalate, diethyl
phthalate,
3o tris(butoxyethyl)phosphate, propylene carbonate, ethylene carbonate,
trimethyl
trimellitate and mixtures thereof are excluded.
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It further relates to a method as defined hereinabove, wherein the pigment III
is an
electrochemically inert solid IITa which is selected from the group consisting
of an
inorganic solid, preferably an inorganic basic solid, selected from the group
consisting of oxides, mixed oxides, carbonates, silicates, sulfates,
phosphates,
amides, imides, nitrides and carbides of the elements of the Ist, ILnd, IIIrd
or Nth
main group or the IVth subgroup of the Periodic Table of the Elements; a
polymer
selected from the group consisting of polyethylene, polypropylene,
polystyrene,
poly(tetrafluoroethylene), poly(vinylidene fluoride), polyamides, polyimides;
a solid
to dispersion containing a polymer of this type; glass powder, nano glass
particles, such
as MonosperC~ (company Merck), micro glass particles, such as Spheriglass~
(company Potters-Ballotini), nano whiskers and a mixture of two or more
thereof, a
molded article being obtained in the process which can be used as a solid
electrolyte
and/or a separator.
Examples to be mentioned are, in particular: oxides such as e.g. silicon
dioxide,
aluminum oxide, magnesium oxide or titanium dioxide, mixed oxides, for example
of the elements silicon, calcium, aluminum, magnesium, titanium; silicates
such as
e.g. ladder-type silicates, inosilicates, phyllosilicates and tectosilicates;
such as
2o talcum, pyrophyllite, muscovite, phlogopite, amphiboles, nesosilicates,
pyroxenes,
sorosilicates, zeolithes, feldspar, glimpse, phyllosilicates; sulfates such as
e.g. alkali
metal sulfates and alkaline earth metal sulfates; carbonates, for example
alkali metal
carbonates and alkaline earth metal carbonates such as e.g. calcium carbonate,
magnesium carbonate or barium carbonate or lithium carbonate, potassium
carbonate or sodium carbonate; phosphates, for example apatites; amides;
imides;
nitrides; carbides; polymers such as e.g. polyethylene, polypropylene,
polystyrene,
polytetrafluoroethylene, poly(vinylidene fluoride), polyamides, polyimides or
other
thermoplastics, thermosets or microgels, cross-linked polymer particles such
as
Agfaperl~ solid dispersions, in particular those containing the abovementioned
3o polymers, and mixtures of two or more of the abovementioned solids.
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Furthermore, as the inert solid IIZa, inorganic solids, which conduct Li-ions,
preferably an inorganic basic solid, which conducts Li-ions, may be used
according
to the invention.
The following may be mentioned:
Lithium borates such as LiaB60a * xHzO, Li3(BOz)3, LizBa07 * xHzO, wherein x
may be a number of from 0 to 20; lithium aluminates, such as LizO * AlzO3 *
HzO,
LizAlzOa, LiAIOz; lithium aluminosilicates, such as lithium containing
zeolithes,
to feldspar, compounds of feldspar-type, phyllosilicates and inosilicates, and
particularly LiAlSiz06 (spodumen), LiAlSiaOio (petullite), LiAlSiOa
(eucryptite),
glimmers, such as K[Li,AI]3[AISi]aO~o(F-OH)z, K[Li,AI,Fe]3 [AISi]a0io(F-OH)z;
li-
thium zeolithes, particularly those in fiber-, sheet-, oder cube-form,
particularly
those having the general formula LiziZO * A1z03 * xSiOz * yHzO wherein z
~ 5 corresponds to the valancy, x=1.8 to about 12 and y=0 to about 8; lithium
carbides,
such as LizCz, Li.~C; Li3N; lithium oxides and mixed oxides, such as LiAIOz,
LizMn03, LizO, LizOz, LizMnOa, LizTi03; LizNH; LiNHz; lithium phosphates, such
as Li3P04, LiP03, LiAIFPOa, LiAI(OH)POa, LiFePOa, LiMnPOa; LizC03; lithium
silicates of the ladder type, sheet type and tecto silicates, such as e.g.
LizSi03,
2o LizSiOa ~d Li6Siz; lithium sulfate, such as LizS04, LiHSOa, LiKSOa; as well
as the
lithium compounds as mentioned under solid nlb, under the proviso that when
used
as solid lea the presence of conductive black is excluded; and mixtures of two
or
more of the Li ion conducting solids as mentioned above.
25 Particularly suitable in this context are basic solids, where basic solids
are to be
understood as those whose mixture with a liquid diluent which contains water
and
itself has a pH of at most 7, has a higher pH than said diluent.
Advantageously, the solids should be very largely insoluble in the liquid used
as an
3o electrolyte and be electrochemically inert in the battery medium.
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The invention further relates to a method, wherein the pigment III is a
compound
)ZIb which, during charging, is able to give off lithium ions and which is
selected
from the group consisting of LiCoOz, LiNiOz, LiNiXCoyOz,
LiNiXCoyAIZOz(O<x,y,z<1), LixMnOz _ -(0<x<1), LiXMnzOa (0<x<2), LixMoOz
(0<x<2), Li;~Mn03 (0<x<1), LiXMnOz (0<x<2), LixMnzOa (0<x<2), LiXV20a
(0<x<2.5), LiXVz03 (0<x<3.5), LixVOz (0<x<1), LiXWOz (0<x<1), LiXW03
(0<x<1), Li;~TiOz (0<x<1), LiXTizOa (0<x<2), Li,~RuOz (0<x<1), LiXFez03
(0<x<2),
LiXFe30a _ _ _(0<x<2), LiYCrz03 (0<x<3), LiXCr30a (0<x<3.8), LirV3S;
(0<x<1.8),
LiXTa2Sz _ _ _ _(0<x<1), LixFeS (0<x<1), LiXFeS2 (0<x<1), LiXNbSz (0<x<2.4),
LiXMoSz
to (0<x<3), LixTiSz _ _ _(0<x<2), LixZrSz (0<x<2), LiXNbSez (0<x<3), LixVSez
(0<x<_1),
LirNiPSz _(0<x_<1.5), LiXFePSz (0<x<1.5), LiNixBi-XOz (0 < x < 1), LiNiXAh-XOz
(0 <
x < 1), LiNirMg~-,~Oz (0 < x < 1), LiNiXCot-XVOa (1 >_ x >_ 0), LiNirCoyMnZOz
(x+y+z = 1), LiFeOz, LiCrTiOa, LiaMbL,~Oa (1,15 >_ a > 0; 1,3 >_ b+c >- 0,8;
2,5 >_ d
>1,7; M - Ni, Co, Mn; L = Ti, Mn, Cu, Zn, alkaline earth metals,
LiCuxuCuY~Mn~z-~:~+y~~0a (2 > x+y > 0), LiCrTiOa, LiGaXMnz-XOa (0,1 >_ x >_
0),
polycarbonsulfides of the general structure: -[C(SX)]n-, VzOs, a mixture of
two or
more thereof, and a mixture of the compound ILTIb with the solid IIZa; and the
mixture I additionally contains from 0.1 to 20 wt%, based on the blend lI, of
conductive black, a molded article being obtained which can be used, in
particular,
2o as a cathode.
moreover, the invention relates to a method, wherein the pigment III is a
compound
>IIc which, during charging, is able to take up lithium ions and which is
selected
from the group consisting of lithium, a lithium-containing metal alloy,
rnicronized
carbon black, natural and synthetic graphite, synthetically graphitized carbon
dust, a
carbon fiber, titanium oxide, zinc oxide, tin oxide, molybdenum oxide,
tungsten
oxide, titanium carbonate, molybdenum carbonate, zinc carbonate, LirMySiOz (1
> x
>_ 0, 1 > y >_ 0, z > 0), SnzBPOa, conjungated polymers such as polypyrroles,
polyanilines, polyacetylenes, polyphenylenes, lithium metal compounds LixM,
such
3o as those, wherein M = Sn, Bi, Sb, Zn, Cd, Pb and 5 >_ x >_ 0; Li-Sn-Cd,
CdO, PbO, a
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mixture of two or more thereof, and a mixture of the compound ITIc with the
solid
Illa; and the mixture I additionally contains up to 20 wt%, based on the blend
II, of
conductive black, a molded article being obtained which can be used, in
particular,
as an anode.
Particularly suitable are pigments III having a primary particle size of from
5 nm to
20 mm, preferably from 0.01 to 10 mm and in particular from 0.1 to 5 mm, the
specified particle sizes being determined by electron microscopy. The melting
point
of the pigments is preferably above the normal operating temperature for the
electro-
l0 chemical cell, melting points of above 120°C, in particular of above
150°C having
proved particularly beneficial.
In this context the pigments, in terms of their external shape, can be
symmetrical, i.e.
have a size ratio height:width:length (aspect ratio) of approximately 1 and be
present
in the form of spheres, granules, approximately round structures, but also in
the form
of any type of polyhedron such as e.g. cuboids, tetrahedra, hexahedra,
octahedra or
as a bipyramid or be distorted or asymmetrical, i.e. have a size ratio
height:width:length (aspect ratio) different from 1 and be present e.g. as
needles,
asymmetric tetrahedra, asymmetric bipyramids, asymmetric hexahedra or
octahedra,
laminae, disks or fibrous structures. Insofar as the solids are present as
asymmetric
particles, the above-specified upper limit for the primary particle size in
each case
refers to the shortest axis.
In the course of the production of the molded articles which can be used as a
cathode
or anode, the conductive black, if present, is preferably added to the blend
II in the
form of a masterbatch. The masterbatch is a composition which contains from 20
to
50 wt% of conductive black, from 5 to 30 wt% of polymeric binder IV and from
30
to 75 wt% of plasticizer IV, the amount and composition chosen of the
masterbatch
being such that, based on the blend II, the amount of conducting salt added in
total
does not exceed 20 wt%. The masterbatch is preferably prepared by compounding
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and melt extrusion of the abovementioned components.
O.Z. 0050/47880
The blends II should comprise, according to the invention, from 1 to 95 wt%,
preferably from 25 to 90 wt% and in particular from 30 to 70 wt% of a pigment
III
and from 5 to 99 wt%, preferably from 10 to 75 wt% and in particular from 30
to 70
wt% of a polymeric binder N, where the polymeric binder should advantageously
have a mean molec-ular weight (number average) of from 5000 to 100,000,000,
preferably from 50,000 to 8,000,000.
to The following additional feedstocks are used in producing the molded
article or in
the mixture I used or the blend II:
Used as the polymeric binders N are thermoplastic and ion-conductive polymers,
examples to be mentioned in particular being:
1) Homopolymers, block polymers or copolymers Na (polymers Na) which can
be obtained by polymerization of
bl) from 5 to 100 wt%, based on the polymer IVa, of a condensation
2o product VI of
a) at least one compound VII which is able to react with a
carboxylic acid or a sulfonic acid or a derivative or a mixture of
two or more of these, and
at least 1 mol per mole of the compound VII of a carboxylic acid
z5 or sulfonic acid VIII which has at least one free-radical poly-
merizable functional group or of a derivative thereof or of a
mixture of two or more of these
and
b2) from 0 to 95 wt%, based on the polymer IVa, of a further compound IX
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having a mean molecular weight (number average) of at least 5000
comprising polyether segments in the main chain or a side chain.
The polymer Na is preferably obtainable via
bl) from 5 to 100 wt%, based on the polymer IVa, of a condensation
product VI of
a) a polyhydric alcohol VII which contains carbon atoms and
l0 oxygen atoms in the main chain,
and
(~) at least 1 mol per mole of the polyhydric alcohol VII of an
a, ~ -unsaturated carboxylic acid VILLI,
and
b2) from 0 to 95 wt%, based on the polymer Na, of a further
2o compound IX having a mean molecular weight (number average)
of at least 5000 comprising polyether segments in the main chain
or a side chain.
Suitable, in principle, as the compound VII which is capable of reacting with
a
carboxylic acid or a sulfonic acid VIII or a derivative or a mixture of two or
more thereof are all compounds which satisfy this criterion.
The compound VII is preferentially selected from the group consisting of a
mono- or polyhydric alcohol which in its main chain solely comprises carbon
3o atoms; a mono- or polyhydric alcohol which in its main chain, in addition
to at
least two carbon atoms, has at least one atom which is selected from the group
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consisting of oxygen, phosphorus and nitrogen; a silicon-containing compound;
an amine having at least one primary amino group; an amine having at least one
secondary amino group; an amino alcohol; a mono- or polyhydric thiol; a
compound having at least one thiol and at least one hydroxyl group; and a
mixture of two or more of these.
Among these, in turn, compounds VII are preferred which have two or more
functional groups which are able to react with the carboxylic acid or sulfonic
acid.
If compounds VII are used which as the functional group contain amino groups,
preference is given to the use of those having secondary amino groups, so that
after the condensation/cross-linking either no free NH groups or only small
amounts of these are present in the mixture Ia.
To be mentioned individually as preferred compounds are:
mono- or polyhydric alcohols whose main chain consists exclusively of carbon
atoms and which have from 1 to 20, preferably from 2 to 20 and in particular
from 2 to 10 alcoholic OH groups, in particular dihydric, trihydric and
2o tetrahydric alcohols, preferably having from 2 to 20 carbon atoms, such as
e.g.
ethylene glycol, propane-1,2- or -1,3-diol, butane-1,2- or -1,3-diol, butene-
1,4-
or butyne-1,4-diol, hexane-1,6-diol, neopentyl glycol, dodecane-1,2-diol,
glycerol, trimethylolpropane, pentaerythritol or sugar alcohols, hydroquinone,
novolak, bisphenol A, an alternative option, however, as follows from the
above definition, being the use of monohydric alcohols such as e.g. methanol,
ethanol, propanol, n-, sec- or t-butanol etc.; furthermore it is also possible
to
employ polyhydroxyolefins, preferably those having two terminal hydroxyl
groups, such as e.g. a,~-dihydroxybutadiene;
polyester polyols such as those known e.g. from Ullinann's Encyklopddie der
technischen Chemie, 4'h edition, vol. 19, pp. 62-65 and obtainable, for
example,
by the reaction of dihydric alcohols with polybasic, preferably dibasic
~~
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polycarboxylic acids;
mono- or polyhydric alcohols which in their main chain, in addition to at
least
two carbon atoms, contain at least one oxygen atom, preferably polyether
alcohols such as e.g. polymerization products of alkylene epoxides, for
example isobutylene oxide, propylene oxide, ethylene oxide, 1,2-epoxybutane,
1,2-epoxypentane, 1,2-epoxyhexane, tetrahydrofuran, styrene oxide, an
additional option being the use of polyether alcohols modified at their
terminal
groups, such as e.g. polyether alcohols modified by means of NH2 terminal
groups; these alcohols preferably have a molecular weight {number average) of
1o from 100 to 5000, more preferably from 200 to 1000 and in particular from
300
to 800; compounds of this type are known per se and are commercially
available, for example, under the brands Pluriol~ or Pluronic~ (BASF Aktien-
gesellschaft);
alcohols as defined above, in which some or all of the carbon atoms have been
replaced by silicon, a particular option in this context being the use of
polysiloxanes or alkylene oxide/siloxane copolymers or mixtures of polyether
alcohols and polysiloxanes, as described, for example, in EP-B 581 296 and
EP-A 525 728, what was said above likewise applying to the molecular weight
of these alcohols;
2o alcohols as defined above, in particular polyether alcohols in which some
or all
the oxygen atoms have been replaced by sulfur atoms, what was said above
likewise applying to the molecular weight of these alcohols;
mono- or polyhydric alcohols which, in their main chain, in addition to at
least
two carbon atoms contain at least one phosphorus atom or at least one nitrogen
atom such as e.g. diethanolamine, triethanolamine;
lactones which are derived from compounds of the general formula HO-(CHz)Z-
COOH, where z is a number from 1 to 20, such as e.g. ~-caprolactone, (~-
propiolactone, Y-butyrolactone or methyl- E -caprolactone;
a silicon-containing compound such as e.g. di- or trichlorosilane,
3o phenyltrichlorosilane, diphenyldichlorosilane, dimethylvinylchlorosilane;
silanols such as e.g. trimethylsilanol;
~
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an amine having at least one primary and/or secondary amino group, such as
e.g. butylamine, 2-ethylhexylamine, ethylenediamine, hexamethylenediamine,
diethylenetriamine, tetraethylenepentamine, pentaethylenehexamine, aniline,
phenylenediamine;
polyetherdiamines such as e.g. 4,7-dioxadecane-1,10-diamine, 4,11-
dioxatetradecane-1,14-diamine;
a mono- or polyhydric thiol such as e.g. aliphatic thiols such as e.g.
methanethiol, ethanethiol, cyclohexanethiol, dodecanethiol; aromatic thiols
such as e.g. thiophenol, 4-chlorothiophenol, 2-mercaptoaniline;
to a compound having at least one thiol and at least one hydroxyl group, such
as
e.g. 4-hydroxythiophenol and monothio derivatives of the above-defined
polyhydric alcohols;
amino alcohols such as e.g. ethanolamine, N-methyl-ethanolamine, N-
ethylethanolamine, N-butylethanolamine, 2-amino-1-propanol, 2-amino-1-
phenylethanol;
mono- or polyaminopolyols having more than two aliphatically bound hydroxyl
groups, such as e.g. tris(hydroxymethyl)methylamine, glucamine, N,N'-bis-
(2-hydroxyethyl)ethylenediamine, and mixtures of these.
It is also possible to use mixtures of two or more of the above-described
compounds VII.
The abovementioned compounds VII are condensed, according to the
invention, with a carboxylic acid or sulfonic acid VIII which has at least one
free-radical polymerizable functional group or with a derivative thereof or a
mixture of two or more of these, at least one, preferably all of the free
groups
capable of condensation within the compounds VII being condensed with the
compound VIII.
3o Suitable in principle as the carboxylic acid or sulfonic acid VIII within
the
scope of the present invention are all those carboxylic and sulfonic acids
which
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have at least one free-radical polymerizable functional group, as are their
derivatives. In this context, the term "derivatives" as used herein comprises
both compounds derived from a carboxylic or sulfonic acid which has been
modified at the acid function (such as e.g. esters, acid halides or acid
anhydrides) and compounds derived from a carboxylic or sulfonic acid which
has been modified on the carbon skeleton of the carboxylic or sulfonic acid,
such as e.g. halocarboxylic or halosulfonic acids.
Particular examples to be mentioned of compound VIII are:
to a,~-unsaturated carboxylic acids or a,'Y-unsaturated carboxylic acids or
derivatives thereof.
Particularly suitable a,~-unsaturated carboxylic acids in this context are
those
of the formula
R1 R2
R3 ~C=C~
COOH
where Rl, RZ and R3 are hydrogen or Ci-Ca-alkyl, among which in turn acrylic
acid and methaclylic acid are preferred; also expediently usable are cinnamic
acid, malefic acid, fiunaric acid, itaconic acid or p-vinylbenzoic acid and
- derivatives of these, such as e.g. anhydrides such as e.g, malefic or
itaconic
anhydride;
halides, in particular chlorides, such as e.g. acryloyl or methacryloyl
chloride;
esters such as e.g. (cyclo)alkyl (meth)acrylates having up to 20 C atoms in
the
alkyl radical, such as e.g. methyl (meth)acrylate, ethyl (meth)acrylate,
propyl -
(meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl
(meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl
(meth)acrylate, benzyl (meth)acrylate, trifluoromethyl (meth)acrylate, hexa-
fluoropropyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, polypropylene-
- CA 02285007 1999-09-22
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O.Z. 0050147880
glycol mono(meth)acrylates, polyethylene mono(meth)acrylates,
poly(meth)acrylates of polyhydric alcohols, such as e.g. glycerol di(meth)-
acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol di- or
tri(meth)acrylate, diethylene glycol bis(mono-(2-acryloxy)ethyl)carbonate,
poly(meth)acrylates of alcohols which themselves in turn have a free-radical
polymerizable group, such as e.g. esters from (meth)acrylic acid and vinyl
andlor allyl alcohol;
vinyl esters of other aliphatic or aromatic carboxylic acids, such as e.g.
vinyl
acetate, vinyl propionate, vinyl butanoate, vinyl hexanoate, vinyl octanoate,
1o vinyl decanoate, vinyl stearate, vinyl palmitate, vinyl crotonate, divinyl
adipate,
divinyl sebacate, vinyl 2-ethylhexanoate, vinyl trifluoroacetate;
allyl esters of other aliphatic or aromatic carboxylic acids, such as e.g.
allyl
acetate, allyl propionate, allyl butanoate, allyl hexanoate, allyl octanoate,
allyl
decanoate, allyl stearate, allyl palmitate, allyl crotonate, allyl salicylate,
allyl
lactate, diallyl oxalate, allyl stearate, allyl succinate, diallyl glutarate,
diallyl
adipate, diallyl pimelate, allyl cinnamate, diallyl maleate, diallyl
phthalate,
diallyl isophthalate, triallyl benzene-1,3,5-tricarboxylate, allyl
fluoroacetate,
allyl perfluorobutyrate, allyl perfluorooctanoate;
~~Y-unsaturated carboxylic acids and derivatives thereof, such as e.g.
2o vinylacetic acid, 2-methylvinylacetic acid, isobutyl 3-butenoate, allyl
3-butenoate, allyl 2-hydroxy-3-butenoate, diketene;
sulfonic acids such as, e.g. vinylsulfonic acid, allyl- and methallylsulfonic
acid,
and their esters and halides, vinyl benzenesulfonate, 4-vinylbenzene-
sulfonamide.
It is also possible for mixtures of two or more of the above-described
carboxylic and/or sulfonic acids to be used.
The polymer Na can be obtained by the reaction of from 5 to 100 wt%,
preferably from 30 to 70 wt%, based on the polymer IVa, of a condensation
- CA 02285007 1999-09-22
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O.Z. 0050/47880
product VI and from 0 to 95 wt%, in particular from 30 to 70 wt%, based on
the polymer IVa, of a compound IX.
2) Homopolymers, block polymers or copolymers Nb (polymers IVb), obtainable
by polymerization of
bl) frorn 5 to 75 wt%, based on the polymer IVb, of an unsaturated
compound X which is capable of free-radical polymerization and differs
from the above carboxylic acid or the sulfonic acid or a derivative
1o thereof, or of a mixture of two or more of these
and
b2) from 25 to 95 wt%, based on the polymer IVb, of a further compound
IX, having a mean molecular weight (number average) of at least 5000
and comprising polyether segments in the main chain or a side chain as
a polymeric binder.
Examples to be mentioned in particular of the compound X which can be used
2o for the preparation of the polymer IVb and is capable of free-radical
polymer
ization include the following:
olefmic hydrocarbons such as e.g. ethylene, propylene, butylene, isobutene,
hexene or higher homologs and vinyl cyclohexane;
(meth)acrylonitrile;
halogen-containing olefinic compounds such as e.g. vinylidene fluoride,
vinylidene chloride, vinyl fluoride, vinyl chloride, hexafluoropropene, tri-
fluoropropene, 1,2-dichloroethylene, 1,2-difluoroethylene and tetrafluoro-
ethylene;
vinyl alcohol, vinyl acetate, N-vinylpyrrolidone, N-vinylimidazole,
vinylformamide;
phosphonitrile chlorides such as e.g. phosphonitrile dichloride,
~
CA 02285007 1999-09-22
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O.Z. 0050/47880
hexachloro(triphosphazene), and their derivatives partially or completely
substituted by alkoxy, phenoxy, amino and fluoroalkoxy groups, i.e.
compounds which can be polymerized to give polyphosphazenes;
aromatic, olefinic compounds such as e.g. styrene, a-methylstyrene;
vinyl ethers such as e.g. methyl, ethyl, propyl, isopropyl, butyl, isobutyl,
hexyl,
octyl, decyl, dodecyl, 2-ethylhexyl, cyclohexyl, benzyl, trifluoromethyl,
hexafluoropropyl, tetrafluoropropyl vinyl ether.
Of course it is also possible to employ mixtures of the abovementioned
l0 compounds X, in which case copolymers are then formed which, depending on
the preparation route, contain the monomers in random distribution or result
in
block copolymers.
These compounds X, like the condensation products VI, are polymerized in a
conventional manner well known to those skilled in the art, preferably by free-
radical polymerization, the molecular weights obtained being subject to the
same points as made below regarding the compound IX.
Potentially suitable, in the first instance, for compound IX are compounds
having a mean molecular weight (number average) of at least 5000, preferably
from 5000 to 20,000,000, in particular from 100,000 to 6,000,000, which are
able to solvate lithium cations and to act as a binder. Examples of suitable
compounds IX include polyethers and copolymers which comprise at least 30
wt% of the following structural unit, based on the total weight of the
compound
IX:
T, 2
~C-C~~' O-
R3 R4
n
~
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O.Z. 0050/47880
where R~, R2, R3 and R4 are aryl, alkyl, preferably methyl, or hydrogen, may
be
identical or different and may include hetero atoms such as oxygen, nitrogen,
sulfur or silicon.
Such compounds are described, for example, in: M. B. Armand et al., Fast Ion
Transport in Solids, Elsevier, New York, 1979, pp. 131-136, or in FR-A
7832976.
The compound IX may alternatively consist of mixtures of such compounds.
l0
The polymer IVb can be obtained by the reaction of from 5 to 75 wt%,
preferably from 30 to 70 wt%, based on the polymer IVb, of a compound X and
from 25 to 95 wt%, in particular from 30 to 70 wt%, based on the polymer IVb,
of a compound IX;
3) Polycarbonates such as e.g. polyethylene carbonate, polypropylene
carbonate,
polybutadiene carbonate, polyvinylidene carbonate.
4) Homopolymers, block polymers and copolymers prepared from
2o a) olefinic hydrocarbons such as e.g. ethylene, propylene, butylene,
isobutene, propene, hexene or higher homologs, butadiene,
cyclopentene, cyclohexene, norbornene, vinylcyclohexane, 1,3-
pentadiene, 1,3-, 1,4-, 1,5-hexadiene, isoprene, vinyl norbornene;
b) aromatic hydrocarbons such as e.g. styrene and methylstyrene;
c) acrylic acid or methacrylic acid ester such as methyl, ethyl, propyl,
isopropyl, butyl, isobutyl, hexyl, octyl, decyl, dodecyl, 2-ethylhexyl,
cyclohexyl, benzyl, trifluoromethyl, hexafluoropropyl, tetrafluoropropyl
acrylate or methacrylate;
d) acrylonitrile, methacrylonitrile, N-methylpyrrolidone, N-
3o vinylimidazole, vinyl acetate;
e) vinyl ethers such as e.g. methyl, ethyl, propyl, isopropyl, butyl,
isobutyl,
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O.Z. 0050/47880
hexyl, octyl, decyl, dodecyl, 2-ethylhexyl, cyclohexyl, benzyl, trifluoro-
methyl, hexafluoropropyl, tetrafluoropropyl vinyl ether;
f) halogen-containing olefinic compounds such as vinyl chloride, vinyl
fluoride, vinylidene fluoride, vinylidene chloride, hexafluoropropene,
trifluoropropene, 1,2-dichloroethene, 1,2-difluoroethene,
tetrafluoroethene.
g) 2-vinylpyridine, 4-vinylpyridine, vinylene carbonate.
Within the preparation of the above mentioned polymers, controlling
compounds, such as e.g. mercaptane may be used if desired or regarded as
being necessary.
5) Polyurethanes, for example obtainable by the reaction of
a) organic diisocyanates having from 6 to 30 C atoms, such as e.g.
aliphatic acyclic diisocyanates such as e.g. 1,5-hexamethylene diisocya-
nate and 1,6-hexamethylene diisocyanate, aliphatic cyclic diisocyanates
such as e.g. 1,4-cyclohexylene diisocyanate, dicyclohexylinethane
diisocyanate and isophorone diisocyanate or aromatic diisocyanates
such as e.g. 2,4-diisocyanotoluene, 2,6-diisocyanotoluene, m-tetra-
2o methylxylene diisocyanate, p-tetramethylxylene diisocyanate, 1,5-
diisocyanatotetrahydronaphthalene and 4,4'-
diisocyanatodiphenylenemethane or mixtures of such compounds
with
b) polyhydric alcohols such as e.g. polyesterols, polyetherols and diols.
The polyesterols are expediently predominantly linear polymers having
terminal OH groups, preferably those having two or three, in particular two OH
terminal groups. The acid value of the polyesterols is less than 10 and prefer-
ably less than 3. The polyesterols can be prepared in a simple manner by
3o esterification of aliphatic or aromatic dicarboxylic acids having from 4 to
15 C
atoms, preferably from 4 to 6 C atoms, with glycols, preferably glycols having
~
CA 02285007 1999-09-22
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O.Z. 0050/47880
from 2 to 25 C atoms, or by polymerization of lactones having from 3 to 20 C
atoms. Examples of dicarboxylic acids which can be used include glutaric acid,
pimelic acid, suberic acid, sebacic acid, dodecanoic acid and preferably
adipic
acid and succinic acid. Suitable aromatic dicarboxylic acids are terephthalic
acid, isophthalic acid, phthalic acid or mixtures of these dicarboxylic acids
with
other dicarboxylic acids, e.g. diphenic acid, sebacic acid, succinic acid and
adipic acid. The dicarboxylic acids can be used individually or as mixtures.
For
the purpose of preparing the polyesterols it may be advantageous for the
dicarboxylic acids to be replaced by the corresponding acid derivatives such
as
to carboxylic acid anhydrides or carboxylic acid chlorides. Examples of
suitable
glycols are diethylene glycol, 1,5-pentanediol, 1,10-decanediol and 2,2,4-
trimethylpentanediol-1,5. Preferentially used are 1,2-ethanediol, 1,3-
propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2,2-
dimethylpropanediol-1,3, 1,4-dimethylolcyclohexane,
1,4-diethanolcyclohexane and ethoxylated or propoxylated products of 2,2-bis-
(4-hydroxyphenylene)propane (bisphenol A). Depending on the desired
properties of the polyurethanes, the polyols may be used on their own or as a
mixture in various quantitative proportions. Suitable as lactones for the
preparation of the polyesterols are, e.g. a,a-dimethyl-~-propiolactone,
'Y-butyrolactone and preferably E-caprolactone.
The polyetherols are essentially linear substances which have terminal
hydroxyl
groups and contain ether bonds. Suitable polyetherols can readily be prepared
by polymerization of cyclic ethers such as tetrahydrofuran or by one or more
alkylene oxides having from 2 to 4 C atoms in the alkylene radical being
reacted with a starter molecule which contains two active hydrogen atoms
bound in the alkylene radical. Examples to be mentioned of alkylene oxides
include ethylene oxide, 1,2-propylene oxide, epichlorohydrin, 1,2-butylene
oxide, 2,3-butylene oxide. The alkylene oxides can be used singly, alternately
in succession or as a mixture. Examples of potentially suitable starter
molecules include water, glycols such as ethylene glycol, propylene glycol,
1,4-
CA 02285007 1999-09-22
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O.Z. 0050/47880
butanediol and 1,6-hexanediol, amines such as ethylenediamine, hexa-
methylenediamine and 4,4'-diaminodiphenylinethane and amino alcohols such
as ethanolamine. Suitable polyesterols and polyetherols and their preparation
are described, for example, in EP-B 416 386, suitable polycarbonate diols,
preferably those based on 1,6-hexanediol, and their preparation are described,
for example, in US-A 4 131 731.
Potentially advantageous, in amounts of up to 30 wt%, based on the total mass
of the alcohols, are aliphatic diols having from 2 to 20, preferably from 2 to
10
1o C atoms, such as 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,6-
hexane-
diol, 1,5-pentanediol, 1,10-decanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-
1,3-propanediol, 2-methyl-2-butyl-1,3-propanediol, 2,2-dimethyl-1,4-
butanediol, 1,4-dimethylolcyclohexane, neopentyl glycol hydroxypivalate,
diethylene glycol, triethylene glycol and methyl diethanolamine or aromatic-
aliphatic or aromatic-cycloaliphatic diols having from 8 to 30 C atoms,
potentially suitable aromatic structures being heterocyclic ring systems or
preferably isocyclic ring systems such as naphthalene and in particular
benzene
derivatives such as bisphenol A, doubly symmetrically ethoxylated bisphenol
A, doubly symmetrically propoxylated bisphenol A, bisphenol A derivatives or
bisphenol F derivatives ethoxylated or propoxylated to a higher degree, and
mixtures of such compounds.
Potentially advantageous in amounts of up to 5 wt%, based on the total mass of
the alcohols, are aliphatic triols having from 3 to 15, preferably from 3 to
10 C
atoms, such as trimethylolpropane or glycerol, the reaction product of such
compounds with ethylene oxide and/or propylene oxide and mixtures of such
compounds.
The polyhydric alcohols may carry functional groups, for example neutral
3o groups such as siloxane groups, basic groups such as, in particular,
tertiary
amino groups or acidic groups or their salts, or groups which are readily
CA 02285007 1999-09-22
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O.Z. 0050147880
converted into acidic groups, these functional groups being introduced via a
polyhydric alcohol. Preferentially, diol components carrying such groups can
be
used, such as N-methyldiethanolamine, diethyl N,N-bis(hydroxyethyl)-
aminomethylphosphonate or 3-sulfopropyl N,N-bis(hydroxyethyl)-2-
aminoacetate or dicarboxylic acids which carry such groups and can be used for
the preparation of polyesterols, such as 5-sulfoisophthalic acid.
Acidic groups include, in particular, the phosphoric acid, phosphonic acid,
sulfuric acid, sulfonic acid, carboxyl or ammonium group.
Examples of groups which are readily converted into acidic groups include the
ester group or salts, preferably of the alkali metals such as lithium, sodium
or
potassium.
6) The above-described polyesterols per se, in which case care should be taken
to
ensure that molecular weights in the range of from 10,000 to 2,000,000,
preferably from 50,000 to 1,000,000 are obtained.
7) Polyamines, polysiloxanes and polyphosphazenes, in particular of the type
2o already discussed in the context of the description of the polymer Nb.
8) Polyetherols such as those described e.g. in the above discussion of the
polymer
IVa as compound IX or in the discussion of the polyurethanes.
Suitable for use as the plasticizer V are aprotic solvents, preferably those
which
solvate Li ions, such as e.g. dimethyl carbonate, ethyl methyl carbonate,
diethyl
carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate,
propylene
carbonate; cyclic carbonates of the fomula CnHn+i Oy, n = 2 to 30, m = 3 to 7,
such as
ethylene carbonate, 1,2-propylene carbonate, 1,3-propylene carbonate, 1,2-
butylene
3o carbonate, 1,3-butylene carbonate, 1,4-butylene carbonate, 2,3-butylene
carbonate;
oligoalkylene oxides such as e.g. dibutyl ether, di-t-butyl ether, dipentyl
ether,
CA 02285007 1999-09-22
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O.Z. 0050/47880
dihexyl ether, diheptyl ether, dioctyl ether, dinonyl ether, didecyl ether,
didoceyl
ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, 1-t-
butoxy-2-
methoxyethane, 1-t-butoxy-1-ethoxyethane, 1,2-dimethoxypropane, 2-methoxyethyl
ether, 2-ethoxyethyl ether, diethylene glycol dibutyl ether, dimethylene
glycol t-butyl
methyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl
ether,
'Y-butyrolactone, dimethylforrnamide; dimethyl- 'Y-butyrolactone, diethyl-1'-
butyrolactone, Y-valerolactone, 4,5-dimethyl-1,3-dioxolane-2-one, 4,4-dimethyl-
1,3-dioxolane-2-one, 4-ethyl-1,3-dioxolane-2-one, 4-methyl-5-ethyl-1,3-
dioxolane-
2-one, 4,5-diethyl-1,3-dioxolane-2-one, 4,4-diethyl-1,3-dioxolane-2-one, 1,3-
dioxane-2-one, 4-methyl-1,3-dioxane-2-one, S-methyl-1,3-dioxane-2-one, 4,4-
dimethyl-1,3-dioxane-2-one, 5,5-dimethyl-1,3-dioxane-2-one, 4,6-dimethyl-1,3-
dioxane-2-one, 4,4,6-trimethyl-1,3-dioxane-2-one, 5,5-diethyl-1,3-dioxane-2-
one,
spiro-(1,3-oxa-2-cyclohexanone)-5',5',1',3'-oxacyclohexane; 4-
dimethylethoxysilyl-
1,2-butylene carbonate; diester of carboxylic acids of the formula
R10COORZOCOOR3 (Rl, R2, R3 = Ct-Czo-hydl'ocarbons), organic ester of the
formula Rl-COORz (Rl and R2 = Ci-Czo-hydrocarbons), hydrocarbons of the
general formula C~Hzn+z with 7 < n < 50; organic phosphorus compounds, in
particular phosphates and phosphonates such as e.g. trimethyl phosphate,
triethyl
phosphate, tripropyl phosphate, tributyl phosphate, triisobutyl phosphate,
tripentyl
2o phosphate, trihexyl phosphate, trioctyl phosphate, tris(2-ethylhexyl)
phosphate, tri-
decyl phosphate, diethyl n-butyl phosphate, tris(butoxyethyl) phosphate,
tris(2-
methoxyethyl) phosphate, tris(tetrahydxofuryl) phosphate, tris(1H,1H,SH-
octafluoro-
pentyl) phosphate, tris(1H,1H-trifluoroethyl) phosphate, tris(2-
(diethylamino)ethyl)
phosphate, tris(methoxyethoxyethyl)phosphate, tris(methoxy-
ethoxy)trifluorphosphazene, tris(methoxycarbonyloxyethyl)phosphate, diethyl
ethylphosphonate, dipropyl propylphosphonate, dibutyl butylphosphonate,
dihexyl
hexylphosphonate, dioctyl octylphosphonate, ethyl dimethyl phosphonoacetate,
methyl diethyl phosphonoacetate, triethyl phosphonoacetate, dimethyl (2-
oxopropyl)phosphonate, diethyl (2-oxopropyl) phosphonate, dipropyl (2-
oxopropyl)
3o phosphonate, ethyl diethoxyphosphinylformate, trimethyl phosphonoacetate,
triethyl
phosphonoacetate, tripropyl phosphonoacetate, tributyl phosphonoacetate;
organic
CA 02285007 1999-09-22
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O.Z. 0050/47880
sulfur compounds such as e.g. sulfates, sulfonates, sulfoxides, sulfones and
sulfites,
such as e.g. dimethyl sulfite, diethyl sulfite, glycol sulfite, dimethyl
sulfone, diethyl
sulfone, dipropyl sulfone, dibutyl sulfone, tetramethylene sulfone,
methylsulfolane,
dimethyl sulfoxide, diethyl sulfoxide, dipropyl sulfoxide, dibutyl sulfoxide,
tetramethylene sulfoxide, ethyl methanesulfonate, 1,4-butanediol bis-
(methanesulfonate), diethyl sulfate, dipropyl sulfate, dibutyl sulfate,
dihexyl sulfate,
dioctyl sulfate, S02C1F;
nitrites, such as e.g. acrylonitrile;
dispersants, in particular having a surfactant structure;
1 o and mixtures of these.
Furthermore, in general suitable organic compounds may be used as plasticizer
V
such as e.g. acids CnHxFy, wherein n=5 to 30, x,y=2n+2; ethers C"HxFyOZ
wherein
n=5 to 30, x+~2n+2, z=1 to 14; ketones CnHXFYO, wherein n=5 tp 30, x+y=2n;
esters C"HxFYOz, wherein n=5 to 30, x+y=2n; carbonates CnHXFy03, wherein n=5
to
30, x+~2n; lactones CnHXFyOz, wherein n=5 to 20, x+y=2n-2; cyclic carbonates
C~HxFy03, wherein n=5 to 20, x+y=2n-2; and boric acid esters wherein
Rl-R4 = Ci-C2o-hydrocarbons and
X = Ci-Cio-hydrocarbons, Si(CH3)z, and
n,m = 1,2
1
R O~ -~R3 O~ 1
~B-O-R
R-O C O
n
R1 O~ /a-R3 Ov
B-O-X-O-B ~B-O-B~
R O \D--R4 n~ O > m
~~
CA 02285007 1999-09-22
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O.Z. 0050147880
Rl Ov /~R3 O~
B-O-B ~B-O-X-O-B~
R2 O \O-R4 n ~ O > m
particularly trimethyl borate, triethyl borate, tripropyl borate, tributyl
borate,
trimethylen borate, 2-methyl-1,3,2-dioxaborinane, 2-ethyl-1,3,2-dioxaborinane,
2-
propyl-1,3,2-dioxaborinane, 2-butyl-1,3,2-dioxaborinane, 2-phenyl-1,3,2-
dioxaborinane.
Furthermore, at least one ester of the formulae (E1) to (ES) as shown below,
may be
used as plasticizer (V):
/ORl
2
B\ OR (E 1 )
\OR
LORI
O=C
\ORZ (E2)
- /oRl
O=P\ OR2
OR3 (E3)
S (-OCH2 CH20CH3)2 (E4)
O
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O.Z. 0050/47880
R4 O~ /ORl
R3 O Sl\OR2 (ES)
wherein R', R2, R3, R4 may be the same or different and represent
independently
from each other a linear or branched Ci-Ca-alkyl group, (-CHz-CHZ-O)n-CH3
wherein n=1 to 3, a C3- to C6-cycloalkyl group, an aromatic hydrocarbon
residue,
which may be substituted,
under the proviso that at least one of the groups R', RZ, R3 or R4 is (-CHz-
CHz-O)n-
CH3 wherein n=1 to 3.
Within the above-metioned esters of the formulae (E1) to (ES), the phosphoric
acid
1 o esters of the formula (E3) are preferably used.
Examples for the group R', RZ and - if present - R3 and/or R4 are methyl,
ethyl, n-
and iso-propyl, n- and tert.-butyl, cyclopentyl, cyclohexyl and benzyl, as
well as (-
CHz-CHz-O)"-CH3 wherein n=1 to 3, however, as akeady outlined above, under the
proviso that at least one of the groups R~, R2, R3 and R4 is (CHz-CH2-O)"-CH3
wherein n=1 to 3, preferably 1 or 2.
More preferably, esters of the general formulae (E1) to (ES), wherein Rl, RZ
and - if
present - R3 and/or R4 are identical and represent -CHa-CHaO-CH3 or (-CHZ-CHz-
2o O)z-CH3, are used. Among those, the respective phosphoric acid esters are
preferred.
Examples for particular preferably used compounds are those of the formulae
(Ela)
to (ESa):
~2 ~2~3~3 (E 1 a)
~C ( OCR-I2CH20C'~i3)2 (E2a)
CA 02285007 1999-09-22
_28_
O.Z. 0050/47880
~P (-~~2 ~2 ~~3~3 (E3a)
O S (-OCH2 CH20CH3)2 (E4a)
//
O
and
Si (-O-CH2 CH2 OCH3)4 (ESa)
With respect to their properties, the esters used herein are extraordinarily
suitable to
be used as plasticizers in films and in general exhibit a viscosity at room
temperature
of c 10 mPas preferably 5 mPas and particularly < 3 mPas. The exhibt boiling
points
of in general about 200°C or higher, preferably about 250°C or
higher and
particularly about 300°C or higher, as rnesured at atmospheric
pressure, respectively.
Furthermore, at the tempreature of use of about -50°C to about
150°C, they exhibit a
low vapour pressure of about 10-5 to 10°. Due to their boiling points
they may be
distilled and thus may be obtained in high purity when prepared. Furthermore,
at
atmospheric pressure these esters are in the liquid state, over a broad
temperature
range. Generally, they are in the liquid state down to a temperature of about -
30°C,
preferably down to about -40°C. The esters as disclosed herein, may be
used as
solvents in electrolyte systems for Li-ion accumulators at at least about
80°C,
preferably at at least about 120°C, more preferably at at least about
150°C.
The esters as used according to the invention may also be used in admixture
with the
2o above-mentioned plasticizers.
Solvent combinations which exhibit a sufficiently low viscosity, which are
capable
of strongly dissolving the ions of the conducting salt, which are in the
liquid state
over a broad temperature range and which are sufficiently electrochemically
and
chemically stabile and which are hydrolysis resistant are preferred.
~
CA 02285007 1999-09-22
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O.Z. 0050/47880
The esters used according to the present invention may be prepared according
to
common processes, as e.g. disclosed in K. Mura Kami, Chem. High Polymers
(Japan), 7, p. 188-193 (1950) and in H. Steinberg Organoboron Chemistry,
chapter
5, J. Wiley & Sons, N.Y. 1964. In general one starts with the acids, acid
anhydrids
or chorids corresponding to the respective esters, such as boric acid,
C(O)Clz,
POC13, SOzCIz and SiCla, and reacts those in a known manner with the
respective
single or polyvalent alcohols or etheroles.
The amount of plasticizer, based on the total weight of the pigment III and
the
polymeric binder IV is from 1 to 200 wt%, preferably from 2 to 100 wt%, more
preferably 2 to 70 wt%.
Suitable as conducting salts are the conducting salts which are generally
known and
are described, for example, in EP-A 96 629. Particularly suitable in this
context are
compounds such as e.g. LiPF6, LiAsFb, LiSbFs, LiCIOa, LiC(CF3SOz)3,
LiN(CF3SOz)z, LiBFa or LiCF3S03, LiN(SOzC"Fzr,+~)z, LiC[(C~Fzn+i)SOz]3,
Li(Cr,Fzn+i)SOz, wherein n=2 to 20, respectively, LiN(SOzF)z, LiAlCla, LiSiFb,
(RSOz)"XLl (nX = 10, iS, zN, zP, 3C, 3Si; R = CmFzm+i wherein m=0-10 or Ci-Czo-
hydrocarbons) and mixtures of such compounds. LiBFa is preferably used as the
2o conductive salt. Particularly preferred is the combination of the esters of
the
formulae (Ela) to (E5a) with LiBFa as the conductive salt. Among those, the
combination of esters of formula (E3a) and LiBFa as the conductive salt are
particularly preferred. These conducting salts are used in amounts of from 0.1
to 50
wt%, preferably from 1 to 10 wt%, in each case based on the mixture.
If required, dispersing resins can be used, to improve dispersion of the
pigments, as
described in the patent EP 940197.
Potentially suitable as a support material for the molded articles produced
according
3o to the invention are the materials usually employed for electrodes,
preferably metals
such as aluminum and copper. Equally, temporary intermediate supports such as
~
CA 02285007 1999-09-22
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O.Z. 0050/47880
sheets, in particular polyester sheets such as polyethylene terephthalate
sheets can be
used. Such sheets can advantageously be provided with a parting layer,
preferably of
polysiloxanes.
Furthermore, the mixtures used according to the invention may, after or during
melt
extrusion, preferably after the latter, be cross-linked in a manner known per
se.
This is effected, for example, by irradiation with ionic or ionizing
radiation, electron
beam, preferably with an acceleration voltage of between 20 and 2000 kV and a
radiation dose of between 5 and 50 Mrad, UV or visible light, with the
advantageous
option, in the usual way, of adding an initiator such as benzyl dimethyl ketal
or
1,3,5-trimethylbenzoyl-triphenylphosphine oxide in amounts of, in particular,
at
most 1 wt%, based on the polymeric binder and carrying out the cross-linking
over a
period of, in general, from 0.5 to 15 minutes, advantageously under inert gas
such as
nitrogen or argon, by thermal free-radical polymerization, preferably at
temperatures
of above 60°C, with the advantageous option of an initiator such as azo-
bis-
isobutyronitrile being added in amounts of, in general, at most 5 wt%,
preferably
from 0.05 to 1 wt%, based on the polymeric binder, by electrochemically
induced
polymerization or by ionic polymerization, for example by acid-catalyzed
cationic
polymerization, potentially suitable catalysts in the first instance being
acids,
preferably Lewis acids such as BFa or, in particular, LiBFa or LiPF6. Lithium
ion-
containing catalysts such as LiBFa or LiPF6 may, in this case, advantageously
remain as a conducting salt within the solid electrolyte or separator.
The present invention further relates to a molded article, preferably a sheet-
type
molded article which can be obtained by a method, which method comprises the
following stage:
I) Compounding and melt extrusion of a mixture I which comprises a blend II
which contains:
~~
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O.Z. 0050/47880
a) from 1 to 95 wt% of at least one pigment III having a primary particle size
of
from 5 nm to 20 mm which is selected from the group consisting of an
electrochemically inert solid Illa, a compound IIIb which during charging is a-
ble to give off lithium ions, and a compound IIIc which during charging is
able to take up lithium ions, and a mixture of the solid IITa with the
compound
IIIb or the compound Illc,
b) from 5 to 99 wt% of at least one polymeric binder IV, and
1o c) from 0 to 200 wt%, based on the total amount of the components a) and
b), of
at least one plasticizes V,
wherein the proportion by weight of the blend II in the mixture I is from 1 to
100
wt%, and
wherein mixtures I comprising blends II containing, as the polymeric binder N,
a
copolymer of vinylidene fluoride (VdF) and hexafluoropropylene (HFP) having an
HFP content of from 8 to 25 wt% and, as the plasticizes V, a compound selected
from the group consisting of dibutyl phthalate, dimethyl phthalate, diethyl
phthalate,
tris(butoxyethyl)phosphate, propylene carbonate, ethylene carbonate, trimethyl
trimellitate and mixtures thereof are excluded.
The present invention further relates to a composite body, preferably in the
form of a
sheet, more preferably in the form of a sheet having a total thickness of from
15 to
1500 mm, in particular having a total thickness of from 50 to 500 mm, which
can
be obtained by a method, which method comprises the following stages:
(I) the preparation of at least one first layer by compounding and melt
extrusion
of a mixture I as defined above, said mixture comprising a blend II which
contains a solid IIIb or a solid lTIc as defined above, respectively;
~
CA 02285007 1999-09-22
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O.Z. 0050/47880
(II] the preparation of at least one second layer by compounding and melt
extrusion of a mixture I as defined above, said mixture comprising a blend II
which contains a solid IITa, as defined herein, and is free from a solid Illrb
or a
solid IZIc, and
(III) a subsequent bringing together of the at least one first layer and the
at least
one second layer by a conventional facing method.
The present invention further relates to a composite body which can be
obtained by
1o a method, which method comprises the following stages:
(I) the preparation of at least one first layer by compounding and melt
extrusion
of a mixture I as defined above, said mixture comprising a blend II which
contains a solid Illb or a solid IIIc as defined above, respectively;
(II) the preparation of at least one second layer by compounding and melt
extrusion of a mixture I as defined above, said mixture comprising a blend II
which contains a solid IIIa, as defined herein, and is free from a solid ITIb
or a
solid Illc, and
(111) a subsequent bringing together of the at least one first layer and the
at least
one second layer by a conventional facing method.
The at least one second layer is preferably prepared on a temporary support.
In the
process it is possible to employ, according to the invention, customarily used
temporary supports such as e.g. a parting sheet made of a polymer or a
preferably
coated paper such as e.g. a siliconized polyester sheet. This second layer
can,
however, alternately be prepared on a permanent support such as e.g. a
collector
electrode or even entirely without a support. In so doing, said layer can be
either
extruded together with the support or extruded directly onto it.
3o For preparing the composite film, smoothing tools, such as chill-roll
devices and
devices for preparing tubular films are preferably used.
~
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O.Z.0050/47880
The process of bringing together or producing the above-defined layers is
effected
by processes under atmospheric pressure for the coating or fabrication of
sheets,
such as e.g. casting or blade coating, and by processing methods under
pressure such
as e.g. extrusion, coextrusion, laminating, facing, calendering or pressing.
If
required, the composite sheet thus produced may be cross-linked or cured by
radiation, electrochemically or thermally.
As is implied by the above it is thus readily possible to provide a composite
body
to comprising the components parting sheet/separator (second layer)/electrode
(first
layer).
It is further possible, by facing on both sides, to provide a composite body
comprising the components anodelseparator/cathode.
The process of charging such composite bodies with an electrolyte and
conducting
salt can be carried out both before the layers are brought together and,
preferably,
after this operation, if required after contact has been made with suitable
collector
electrodes, e.g. a metal foil, and even after the layers have been introduced
into a
2o battery jacket, the special microporous structure of the layers, if the
mixture
according to the invention is used, in particular owing to the presence of the
above-
defined solid in the separator and possibly in the electrodes, enabling the
electrolyte
and the conducting salt to be absorbed and the air in the pores to be
displaced. The
charging operation can be carried out at temperatures of from 0°C to
approximately
100°C, depending on the electrolyte employed.
The molded articles are produced by compounding and melt extrusion, preferably
at
from about 50 to about 250°C.
3o The equipment used for extrusion in this context preferably is in the form
of a
~~
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O.Z. 0050/47880
plasticating single-screw extruder such as e.g. a Berstorff single-shaft
mixing
extruder, a Frenkel mixer, a plasticator or a Buss co-kneader, a twin-screw
extruder
of a corotating or counterrotating type, such as e.g. an extruder with COLOMBO
screws, an extruder with closely meshing ZSK screws, an extruder with Holo-
Flite
twin screws, a Leistritz kneading pump, an extruder with a Pasquetti twin
screw, an
extruder with cotruder screws, an extruder of the Kestermann type, an extruder
with
Mapre twin screws, a GETECHA compounding extruder, an Anger tandem
extruder, a Zimmermann-Jansen extruder, a twin-shaft continuous kneader such
as
e.g. a DSM twin-shaft mixer, an Eck mixtruder, an FCM kneader or a List all-
phase
1o appliance or a continuous multishaft extruder such as e.g. a four-screw
extruder or a
planetary gear extruder or a combination of two or more of these.
Suitable as particularly preferred appliances are single- and twin-screw
machines
such as e.g. single-shaft mixing extruders (Reifenhauser, Krauss Maffei,
Berstorff),
corotating or counterrotating closely meshing twin-screw kneaders (Werner and
Pfleiderer, Berstorff, APV), multiscrew extruders, Buss co-kneaders or
counterrotating, nonmeshing kneaders (Farrel, JSW).
Screws and cylinders of the continuous-operation extrusion plant ZSK 30 are of
2o modular design. To achieve adequate plastication, dispersion and
homogenization of
the individual components, the process section consists of at most 15 cylinder
zones,
corresponding to 45 units in length per diameter. Each zone is separately
equipped
with an electric heater. The casings are cooled with compressed air or water.
The screw consists of a plurality of conveying, plasticating and mixing zones.
A
special configuration of different kneading and mixing elements is required
for
gentle, homogeneous dispersion of the solids, explicitly of the inorganic
pigments,
in the polymeric binder.
3o If the molded article according to the invention is to be employed as a
solid
electrolyte in an electrochemical cell it is advisable to incorporate a
dissociable,
~
CA 02285007 1999-09-22
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O.Z. 0050/47880
lithium cation-containing compound, a conducting salt as defined above and
further
additives such as, in particular, organic solvents, referred to as
electrolyte.
These substances can be admixed to the suspension, in part or in their
entirety, when
the layer is being produced, or can be introduced into the layer after it has
been
produced.
Potentially suitable organic electrolytes include the esters of formulae (E1)
to (ES)
and the compounds discussed above in the category "plasticizer V", preference
being
given to the use of those esters, particularly those of the formula (E3), and
the
customary organic electrolytes, preferably esters such as ethylene carbonate,
propylene carbonate, dimethyl carbonate and diethyl carbonate or mixtures of
such
compounds.
Solid electrolytes, separators and/or electrodes according to the invention,
which are
suitable for electrochemical cells, should advantageously have a thickness of
from 5
to 500 mm, preferably from 10 to 500 mm, more preferably from 10 to 200 mm
and in particular from 20 to 100 mm.
As implied by the above, the present invention also relates to the use of a
molded
article according to the invention or a composite body according to the
invention or
of a molded article or composite body produced by means of a method according
to
the invention for producing a solid electrolyte, a separator, an electrode, in
a sensor,
an electrochromic window, a display, a capacitor or an ion-conducting foil.
The invention further relates to a separator, a solid electrolyte, an
electrode, a sensor,
an electrochromic window, a display, a capacitor or an ion-conducting foil
comprising a molded article or composite body according to the invention or a
molded article or composite body produced according to the invention, and to
an
3o electrochemical cell comprising a separator, solid electrolyte or an
electrode as
defined above or to a combination of two or more of these.
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O.Z. 0050/47880
This electrochemical cell can be used, in particular, as a motor vehicle
battery,
appliance battery or flat-type battery.
Furthermore, the present invention also provides a motor vehicle battery,
appliance
battery or flat-type battery comprising an electrochemical cell as described
above.
EXAMPLES
to
To illustrate what happens, in principle, within the method according to the
invention, the present application is accompanied by three figures.
Figure 1 shows a schematic depiction of the production of a cathode foil by
means of an extruder and an extruder with an ancillary extruder;
Figure 2 shows a schematic depiction of a coextrusion of a mixture used
according to the invention, together with a PET sheet;
2o Figure 3 shows a schematic depiction of the production of a cathode
(LiMn20a) and an anode foil (MCMB).
First of all, the principles of the production process according to the
invention, as
they are shown schematically in Figure 1, will be described by way of example
relating to a corotating, closely meshing twin-screw kneader ZSK 30 from
Werner
and Pfleiderer.
The corotating and closely meshing and thus self cleaning extruder (E)
consists of a
plurality (up to 15) of variable fittable individual zones which can be
temperature
3o controlled via heating circuits.
~
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Addition of the components:
O.Z. 0050/47880
a) The polymers (P) were homogeneously dispersed, in a fluid mixer, with the
pigment and part of the plasticizes. The addition was carried out via a
proportioning balance. Where necessary, the extruder was inerted with
nitrogen.
b) If required, the plasticizes was added via a proportioning pump in the
homogenizing section of the extruder.
to
c) The conductive black (LR) was added via an ancillary extruder (SE) in the
homogenizing phase. The ancillary extruder was a single- or twin-shaft
extruder. If required, a homogeneous melt of polymer, plasticizes and con-
ductive black and, where appropriate, dispersing resin was prepared in the
ancillary extruder and introduced laterally into the main extruder. The sheet
was discharged via a flat-sheet die and calendered. If required, the sheet was
coextruded between two sheets (e.g. polyethylene terephthalate (PET))
(Figure 2). The thickness of the battery foils was between 10 and 1000 mm.
2o Among the advantages of the production process according to the invention
the
following can be mentioned:
1. Solvent can be dispensed with
2. Drying of the battery foils can be dispensed with
3. Extraction and extraction solvent can be dispensed with
4. The sheet can be incorporated into the battery without further pretreatment
5. More homogeneous dispersion of the pigments
6. Better mechanical stability of the films (than sheeting produced via
casting
technology.
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Example l: Preparation of a cathode foil
4.910 g of LiMnzOa
O.Z. 00501=X7880
1.310 g of poly(vinylidene fluoride)/hexafluoropropene copolymer
Kynar~ 2801 (Elf Atochem)
1.030 g of conductive carbon black SuperO P (~~I1VI Carbon)
2.740 g of tributyl phosphate (TBP)
Extruder configuration:
Corotating twin-shaft main extruder ZSK30 with 10 variable heatable heating
zones.
In the fourth zone a corotating twin-shaft ancillary extruder ZSK30 with 6
variable
heatable heating zones was attached.
Preparation:
180 g/h of a blend of 100 parts of Kynar~ 2801 and 5 parts of propylene
carbonate
and 442 glh of conductive black Super~ P were metered into the first zone of
the
ancillary extruder ZSK30. In addition, 1075 g/h of propylene. carbonate were
2o pumped into the homogenizing section (zone 2) of the ancillary extruder.
This melt
was introduced into the homogenizing section (zone 4) of the main extruder. In
addition, 2600 g of a mixture of 15.1 parts of Kynar~ 2801, 81.1 parts of
LiMnzOa
and 3.8 parts of propylene carbonate were metered into the first zone of the
main
extruder. The internal temperature in the two extruders was 150°C. Via
a heatable
flat film die (150°C) having a gap width of 5 mm the melt was
discharged and
coextruded between two PET sheets and then calendered.
The sheet obtained had the following characteristics:
3o Surface resistance: 140 Ohms
~
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Sheet thickness: 100-500 mm
Example 2: Preparation of an anode foil
Composition:
O.Z. 0050/47880
5600 g of MCMB (Osaka Gas)
1500 g of poly(vinylidene fluoride)/hexafluoropropene copolymer
Kynar~ 2801 (Elf Atochem)
l0 400 g of conductive black SuperC~ P (M1VIM Carbon)
2500 g of tributyl phosphate (TBP)
Extruder configuration: see Example 1
Preparation:
180 g/h of a mixture of 100 parts of Kynar~ 2801 and 5 parts of propylene
carbonate and 150 glh of conductive black Super~ P (SP) were metered into the
first zone of the ancillary extruder ZSK30. In addition, 841 g/h of propylene
2o carbonate were pumped into the homogenizing section (zone 2) of the
ancillary
extruder. This melt was introduced into the homogenizing section (zone 4) of
the
main extruder.
In addition, 2600 g/h of a blend of 15.1 parts of Kynar~ 2801, 80.8 parts of
MCMB
and 3.4 parts of propylene carbonate were metered into the first zone of the
main
extruder. The internal temperature in the two extruders was 150°C.
Via a heatable flat film die (150°C) having a gap width of 5 mm the
melt was
discharged and coextruded between two PET sheets and then calendered.
CA 02285007 1999-09-22
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The sheet obtained had the following characteristics:
Surface resistance: 80 Ohms
Sheet thickness: 50 - 300 mm
O.Z. 0050/47880
The preparation of the abovementioned cathode and anode foils is shown
schematically in Figure 3.
Example 3: Preparation of a separator foil
io
3000 g of poly(vinylidene fluoride)/hexafluoropropene copolymer
Kynar~ 2801 (Elf Atochem)
2000 g of Aerosil~ (AE) R 812 (Degussa)
5000 g of tributyl phosphate
Preparation:
4500 g/h of a mixture of 30 parts of Kynar~ 2801, 20 parts of Aerosil~ R 812
and
50 parts of tributyl phosphate are metered into a corotating twin-shaft
extruder
2o ZSK40 with 10 variable heatable heating zones. The internal temperature in
the
extruder is 150°C. The melt is discharged via a heatable flat filin die
having a gap
width of 1 mm and is coextruded between two PET sheets and then calendered.
Sheet thickness: from 20 to 100 mm
Example 4
3004 g of polymethacrylate (Luryl~ PMMA G88, BASF)
2000 g of Aerosil~ R 812 (Degussa)
5000 g of tributyl phosphate
CA 02285007 1999-09-22
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Preparation as in Example 3
Example 5
3000 g of polyacrylonitrile (Dralon~ T, Bayer)
2000 g of Aerosil~ R 812 (Degussa)
5000 g of tributyl phosphate
to Preparation as in Example 3
Example 6
3000 g of polyethylene (Lupolen~, BASF)
2000 g of Aerosil~ R 812 (Degussa)
5000 g of tributyl phosphate
Preparation as in Example 3
Example 7
3000 g of polypropylene (Novolen~, BASF)
2000 g of Aerosil~ R 812 (Degussa)
5000 g of tributyl phosphate
Preparation as in Example 3
Example 8
O.Z. 0050/47880
3000 g of poly(vinylidene fluoride)/hexafluoropropene copolymer
3o Kynar~ 2801 (Elf Atochem)
2000 g of Aerosil~ R 812 (Degussa)
CA 02285007 1999-09-22
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5000 g of dibutyl carbonate
Preparation as in Example 3
Example 9
O.Z. 0050/47880
3000 g of poly(vinylidene fluoride)Ihexafluoropropene copolymer
Kynar~ 2801 (Elf Atochem)
1500 g of Aerosil~ R 812 (Degussa)
1000 g of wollastonite (Tremin~ 8000 EST, Quarzwerke, Frechen)
5000 g of tributyl phosphate
Preparation as in Example 3
Example 10
2000 g of poly(vinylidene fluoride)/hexafluoropropene copolymer
Kynalfl 2801 (Elf Atochem)
1000 g of polyethylene oxide) (Polyox~, Union Carbide)
2000 g of Aerosil~ R 812 (Degussa)
5000 g of dibutyl carbonate
Preparation as in Example 3.
Example 11
Using the cathode foil according to Example 1, the anode foil according to
Example
2 and the separator foil according to Example 3, a composite body having the
following structure was fabricated by laminating at a temperature of 140
°C:
CA 02285007 1999-09-22
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Cathode foil/metal lattice foil (aluminum)/cathode foil
Separator foil
Anode foil/metal lattice foil (copper)/cathode foil.
O.Z. 0050/47880
The composite body was immersed for half an hour in a 1 molar solution of
LiPF6 in
dimethyl carbonate/ethylene carbonate and then introduced into a flat-type
battery
jacket. The composite body had good resistance to swelling.
