Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02708451 2010-12-01
CONNECTING STRUCTURE FOR EXTERIORLY CONNECTING
BATTERY CELLS
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a connecting structure for exteriorly
connecting battery cells which is weidless and resistant to oxidation and can
provide
a high conductivity connection among many battery cells.
Description of the Prior Art
The existing high power battery assemblies are mainly constructed by
connecting multiple battery cells in series, parallel or series-parallel
through
connecting sheets. The positive and the negative electrode terminals of the
respective
battery cells are normally made of the nickel or nickel-plated metal, and so
are the
connecting sheets because of the advantage that nickel is resistant to
oxidation and
hence more secure for long services. As for the battery cells 11 in a
conventional
battery assembly, as shown in Figs. I and 2, no matter in serial or parallel
configuration, they are all connected by a connecting sheet 10 welded to the
metallic
electrode terminals 12 of the battery cells 11 through several welding spots
13 which
could reduce the external contact resistance of the battery assembly.
It is to be noted that, the above connecting technology for conventional
battery cell can electrically connect two battery cells through nickel
connecting
sheets by spot welding; but, it suffers from many disadvantages such as:
1. After being used for a long time, the nickel connecting sheets will still
be
eventually oxidized or contaminated with foreign matters, thus increasing the
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electric resistance of the connecting sheets.
2. The nickel connecting sheets are connected to the electrode terminals of
the
battery cells through the welding spots typically in small contact areas,
resulting in
high contact resistance, thus causing increase in temperature of the electrode
terminals of the battery cells as well as the welding spots plus extra power
losses of
the battery cells during the recharging or discharging processes.
3. The nickel connecting sheets are expensive; and, the welding process is
time-consuming and labor intensive, making the conventional battery connecting
technology uneconomic.
Hereafter, the present invention has arisen to mitigate and/or obviate the
afore-described disadvantages.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide a connecting
structure for exteriorly connecting battery cells in accordance with the
present
invention mainly utilizes at least one connecting graphite alloy block serving
as a
bridge for connecting two battery cells in series or parallel. In the present
invention,
the connecting graphite alloy block is connected to the electrode terminals of
the
battery cells in a direct contact manner to realize a highly conductive
connection
without utilization of the conventional welding procedures. Furthermore, the
connecting graphite alloy block is less-expensive compared to nickel so that
the
production cost can be greatly reduced.
The secondary objective of the present invention is to provide a connecting
structure for exteriorly connecting battery cells which mainly utilizes a
connecting
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graphite alloy block to electrically connect two battery cells in series or
parallel. The
connecting graphite alloy block by itself is resistant to oxidation. After
close mutual
contact, the connecting graphite alloy block and the positive, the negative
electrode
terminals of the battery cells will start a process of dissolving in each
other, namely
the process of carbon particles of the connecting graphite alloy block
substituting for
the foreign matters on the surfaces of the negative and the positive electrode
terminals of the battery cells so as to fill the voids in the metallic
surfaces of the
negative and the positive electrode terminals of the battery cells until
forming a
carbon-nickel miscible alloy, thus ensuring a smooth large-current discharge
due to
reduction of the external connection resistance.
In order to achieve the above objectives, a connecting structure for
exteriorly
connecting battery cells in series in accordance with the present invention
comprises:
a first battery cell which is exteriorly provided with a positive electrode
terminal
and a negative electrode terminal both made of nickel-plated metal and served
as
power output terminals of the first battery cell; at least one connecting
graphite alloy
block which is made of a graphite alloy selected from a group consisting of
silver
graphite, copper graphite, and silver-copper graphite and connected to the
positive
electrode terminal of the first battery cell; and a second battery cell which
is
exteriorly provided with a positive electrode terminal and a negative
electrode
terminal both made of nickel-plated metal and served as power output terminals
of
the second battery cell. The negative electrode terminal of the second battery
cell is
connected to the connecting graphite alloy block so as to connect the first
battery cell
and the second battery cell in series.
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Furthermore, a connecting structure for exteriorly connecting battery cells in
parallel comprises: a first battery cell which is exteriorly provided with a
positive
electrode terminal and a negative electrode terminal both made of nickel-
plated
metal and served as power output terminals of the first battery cell; at least
one first
connecting graphite block which is made of a graphite alloy selected from a
group
consisting of silver graphite, copper graphite, and silver-copper graphite and
connected to the positive electrode terminal of the first battery cell; a
second battery
cell which is exteriorly provided with a positive electrode terminal and a
negative
electrode terminal both made of nickel-plated metal and served as power output
terminals of the second battery cell, the positive electrode terminal of the
second
battery cell is connected to the first connecting graphite block; and at least
one
second connecting graphite block which is made of a graphite alloy selected
from a
group consisting of silver graphite, copper graphite, and silver-copper
graphite and
connected to the negative electrode terminal of the first battery cell and the
negative
electrode terminal of the second battery cell so as to connect the first and
the second
battery cells in parallel.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a partial perspective view of a conventional battery assembly which
is constructed by connecting battery cells in series through a nickel sheet;
Fig. 2 is a structural view of another conventional battery assembly which is
constructed by connecting battery cells in parallel through a nickel sheet;
Fig. 3 is a schematic view of a connecting structure for exteriorly connecting
battery cells in series by connecting graphite alloy block;
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Fig. 4 is a schematic view of a connecting structure for exteriorly connecting
battery cells in parallel by connecting graphite alloy block;
Fig. 5-1 shows the respective electrode terminals of the battery cell being
contaminated with foreign matters on a surface thereof in accordance with the
present invention;
Fig. 5-2 shows the foreign matter being replaced by carbon particles after the
connecting graphite alloy block in contact with the surface of the electrode
terminal
in accordance with present invention; and
Fig. 6 is a side view showing that how the battery cells are connected in
series-parallel by the connecting graphite alloy block in accordance with the
present
invention to construct a battery assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be easily comprehended from the following
description when viewed together with the accompanying drawings, which show,
for
purpose of illustrations only, the preferred embodiment in accordance with the
present invention.
Referring to Fig. 3, when two battery cells are connected in series, between a
first and a second battery cell 20, 40 is connected at least one connecting
graphite
alloy block to improve the electric conductivity between the first and the
second
battery cells 20, 40.
The first battery cell 20 is a cylindrical battery cell and exteriorly
provided on
both ends thereof with a positive electrode terminal 21 and a negative
electrode
terminal 22 both being made of nickel-plated metal and served as power output
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terminals of the first battery cell 20.
The connecting graphite alloy block 30 is made of a graphite alloy selected
from a group consisting of silver graphite (silver-carbon alloy), copper
graphite
(copper-carbon alloy), and silver-copper graphite (silver-copper-carbon
alloy). The
connecting graphite alloy block 30 is electrically connected to the positive
electrode
terminal 21 of the first battery cell 20 in a close contact manner.
The second battery cell 40 is exteriorly provided on both ends thereof with a
positive electrode terminal 41 and a negative electrode terminal 42 both being
made
of nickel-plated metal and served as power output terminals of the second
battery
cell 40. The negative electrode terminal 42 of the second battery cell 40 is
electrically connected to the connecting graphite alloy block 30 in a close
contact
manner. A spring 50 and a supporting plate 51 are employed to push against the
connecting graphite alloy block 30 in close contact with the first and the
second
battery cells 20, 40. Thereby, the first and the second battery cells 20, 40
are
connected in series.
In addition, the negative electrode terminal 22 of the first battery cell 20
and
the positive electrode terminal 41 of the second battery cell 40 each can be
connected to a graphite terminal 401, 402 as a final power output terminal
thereof.
Each of the graphite terminals 401, 402 is interiorly provided with a wire
403, 404
serving as a power output wire thereof
Further referring to Fig. 4, when two battery cells are connected in parallel,
a
first connecting graphite alloy block and a second connecting graphite alloy
block
are employed for making electrical connection between the first battery cell
and the
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second battery cell in parallel in order to improve the electric conductivity
between
the first and the second battery cells.
The first battery cell 60 is a cylindrical battery cell and exteriorly
provided on
both ends thereof with a positive electrode terminal 61 and a negative
electrode
terminal 62 both being made of nickel-plated metal and served as power output
terminals of the first battery cell 60.
The first connecting graphite alloy block 70 is made of a graphite alloy
selected from a group consisting of silver graphite (silver-carbon alloy),
copper
graphite (copper-carbon alloy), and silver-copper graphite (silver-copper-
carbon
alloy). The first connecting graphite alloy block 70 is electrically connected
to the
positive electrode terminal 61 of the first battery cell 60 in a close contact
manner.
The second battery cell 80 is a cylindrical battery cell and exteriorly
provided
on both ends thereof with a positive electrode terminal 81 and a negative
electrode
terminal 82 both being made of nickel-plated metal and served as power output
terminals of the second battery cell 80. The positive electrode terminal 81 of
the
second battery cell 80 is electrically connected to the first connecting
graphite alloy
block 70 in a close contact manner.
The second connecting graphite alloy block 90 is made of a graphite alloy
selected from a group consisting of silver graphite (silver-carbon alloy),
copper
graphite (copper-carbon alloy), and silver-copper graphite (silver-copper-
carbon
alloy. The second connecting graphite alloy block 90 is connected to the
negative
electrode terminal 62 of the first battery cell 60 and the negative electrode
terminal
82 of the second battery cell 80. Two sets of springs 50a, 50b and supporting
plates
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51a, 51b are employed for pushing against the first and the second connecting
graphite alloy blocks 70, 90, respectively in order to tightly contact the
first and the
second battery cells 60, 80. Thereby, the first and the second battery cells
60, 80 are
connected in parallel.
In addition, the first and the second connecting graphite alloy blocks 70, 90
each are interiorly provided with a wire 405, 406 serving as a power output
wire
thereof.
The aforementioned is the summary of the positional and structural
relationship of the respective components of the preferred embodiment in
accordance with the present invention.
As for the function of the present invention, the present invention mainly
utilizes connecting graphite alloy blocks to directly connect the battery
cells in series
or parallel without utilization of the conventional welding procedures, thus
improving the connective conductivity and reducing the production costs
because of
elimination of the conventional welding procedure.
It is to be noted that, referring to Fig. 5-1, the negative electrode terminal
22
and the positive electrode terminal 41 of the first and the second battery
cells 20, 40
are both made of the nickel-plated metal, the positive and the negative
electrode
terminals 41, 22 each are adhered with foreign matters 500 or oxides 200 on a
surface thereof, the foreign matters 500 or oxides 200 will increase the
connection
resistance during the discharging process of the first and the second battery
cells 20,
40 while reducing the discharging power efficiency of the battery cells.
Referring to
Fig. 3 and Fig. 5-2, showing how to realize high conductivity connection
between
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battery cells, the connecting graphite alloy block 30 is electrically
connected to the
positive and the negative electrode terminals 41, 22 of the first and the
second
battery cells 20, 40; the connecting graphite alloy block 30 by itself is
resistant to
oxidation, and the connecting graphite alloy block 30, and the positive, the
negative
electrode terminals 41, 22 of the first and the second battery cells 20, 40
will
dissolve into each other after mutual contact, that is, the carbon particles
600 of the
connecting graphite alloy block 30 will substitute for the foreign matters 500
or
oxides 200 on the positive and the negative electrode terminals 41, 22 made of
the
nickel-plated metal to fill in the voids in the positive and the negative
electrode
terminals 41, 22, and then form a carbon-nickel miscible alloy, thereby
improving
the connective conductivity among the connecting graphite alloy block 30, the
first
battery cell 20 and the second battery cell 40. In other words, after the
battery
assembly in accordance with the present invention is switched on, electric
current
will flow between the first battery cell 20, the connecting graphite alloy
block 30 and
the second battery cell 40 smoothly through the connecting structure for
exteriorly
connecting battery cells of the present invention without being affected by
the
inherent resistance caused by the oxides 200 or the foreign matters 500, thus
not
only reducing the external connection resistance between the first and the
second
battery cells 20, 40, but facilitating the successful discharging of the first
and the
second battery cells 20, 40.
Referring to Fig. 6, when plural battery cells 301 are connected in series,
parallel or series-parallel to construct a high-power battery assembly 300
through
plural connecting graphite alloy blocks 302 of the present invention, since
the
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connecting graphite alloy blocks 302 will dissolve into the positive and the
negative
electrode terminals both being made of nickel-plated metal to improve the
connective conductivity between the respective battery cells 301, the power
loss of
the external resistance of the battery assembly 300 is comparably less than
that of the
conventional battery assembly in which the battery cells are connected through
nickel sheets by spot welding. Evidently, the external resistance of the
battery
assembly which is constructed by making use of the connecting technology of
present invention is relatively small, and the contact resistance of the
battery cells
301 and the connecting graphite alloy blocks 302 is reduced which resulting in
reduction of working temperature. In other words, the discharging losses of
the
battery assembly which is constructed by making use of the technology of the
present invention are reduced, and the power of the battery assembly can be
delivered smoothly in high efficiency.
While we have shown and described various embodiments in accordance with
the present invention, it is comprehensive to those skilled in the art that
further
embodiments may be made without departing from the scope of the present
invention.
