JP4956777B2 - Bipolar battery, battery pack and vehicle equipped with these batteries - Google Patents

Description

  The present invention relates to a bipolar battery having a heat-sealing seal member for preventing electrolyte leakage at the periphery of a bipolar electrode, an assembled battery, and a vehicle equipped with these batteries.

  A bipolar battery is formed by alternately laminating a bipolar electrode having a positive electrode layer formed on one surface of a current collector and a negative electrode layer formed on the other surface, and an electrolyte layer for performing ion exchange between the bipolar electrodes. Do it. When the electrodes are in contact with each other at the end of this type of bipolar battery, they are short-circuited, and when the electrolyte layers are in contact with each other, a liquid junction occurs.

As a countermeasure, Japanese Patent Publication No. 11-204136 (Patent Document 1) discloses that a positive electrode, a negative electrode, and a unit battery constituted by sandwiching a separator impregnated with an electrolyte between these electrodes are covered with an insulator. In addition, it is disclosed that a liquid junction or short circuit between electrodes is prevented by laminating a current collector.
Japanese Patent Publication No.11-204136

  By the way, in the bipolar battery, the peripheral part of each unit battery is sealed with a heat-sealing seal member in order to prevent the electrolyte from seeping out. This sealing member is heat-sealed to the peripheral part of the electrode, that is, near the edge part of the current collector, and prevents internal leakage due to contact between the current collectors in addition to preventing leakage of the electrolyte.

  However, a material having flexibility such as various resin materials and rubber is used as a constituent material of the seal member, and a very thin space (1 μm to 100 μm) between the electrodes is sealed. Therefore, when heat pressing is performed in order to heat-seal the sealing member, there is a problem that the edge portion of the current collector breaks through the sealing member and the electrodes are brought into contact with each other to cause a short circuit.

  In order to prevent tearing of the seal member at the edge portion of the current collector, if the heating temperature or pressure of the heat press of the heat-sealing seal material is reduced, the heat from the heat press does not reach the central part in the stacking direction, and the seal There was a problem that became incomplete.

  The present invention prevents tearing of the sealing member at the edge portion of the current collector, can completely seal the peripheral portion of the bipolar electrode, and prevents electrolyte leakage and short circuit due to contact between the current collectors It is an object of the present invention to provide a bipolar battery, an assembled battery, and a vehicle equipped with these batteries.

  In order to achieve the above object, a bipolar battery according to the present invention comprises a bipolar electrode in which a positive electrode layer is formed on one surface of a current collector and a negative electrode layer is formed on the other surface, and an ion between the bipolar electrodes. A bipolar battery having a heat-sealing seal member for forming a power generation element by alternately laminating a plurality of electrolyte layers to be exchanged and preventing leakage of electrolyte at the periphery of the electrode, The sealing member includes a non-thermally fused portion at an edge portion of the current collector.

  According to the bipolar battery configured as described above, since the heat-sealing seal member has the non-heat-sealing portion at the edge portion of the current collector, a heat press is used to heat-seal the sealing member. The peripheral portion of the bipolar electrode can be completely sealed without breaking the sealing member at the edge portion of the current collector. Therefore, it is possible to prevent a short circuit due to leakage of the electrolyte or contact between the current collectors.

  Embodiments of a bipolar battery, an assembled battery, and a vehicle equipped with these batteries according to the present invention will be described below in detail with reference to the drawings. In the drawings cited in the following embodiments, the thickness and shape of each layer constituting the bipolar battery are exaggerated, but this is done to facilitate understanding of the contents of the invention. Yes, it is not consistent with the thickness and shape of each layer of an actual bipolar battery.

  FIG. 1 is an external view of a bipolar battery according to the present embodiment. As shown in FIG. 1, the bipolar battery 100 has a rectangular flat shape, and a positive electrode tab 120 </ b> A and a negative electrode tab 120 </ b> B are drawn out from both sides of the bipolar battery 100. The power generation element 160 is wrapped with an exterior material (for example, a laminate film) 180 of the bipolar battery 100, and the periphery thereof is heat-sealed. The power generation element 160 is sealed with the positive electrode tab 120A and the negative electrode tab 120B pulled out. .

  FIG. 2 is a schematic configuration diagram of the inside of the bipolar battery according to the present embodiment. FIG. 3 is a schematic view of a situation in which a heat press is applied to the heat-sealing seal member. 4 to 8 are views for explaining a seal structure in the present embodiment.

  The bipolar battery 100 according to the present embodiment can be formed by using various lamination methods such as a slurry coating method and a printing method. In this embodiment, the power generation element 160 is formed by using the slurry coating method. Form.

First, the positive electrode slurry is applied to one surface of a stainless steel foil (SUS foil) that is the current collector 200 and dried to form the positive electrode layer 210. As the positive electrode slurry, for example, a mixture of a positive electrode active material such as LiMn ₂ O _{4 and} a conductive assistant such as acetylene black, a binder such as PVDF, and a slurry viscosity adjusting solvent such as NMP is used.

  Next, a negative electrode slurry is applied to the opposite surface of the current collector (SUS foil) 200 to which the positive electrode layer 210 is applied, and dried to form the negative electrode layer 220. As the negative electrode slurry, a mixture of a negative electrode active material such as hard carbon, a binder such as PCDF, and a slurry viscosity adjusting solvent such as NMP is used.

  In this manner, the positive electrode layer 210 and the negative electrode layer 220 are formed on both surfaces of the current collector (SUS foil) 200, whereby the bipolar electrode 230 is formed. Then, the bipolar electrode 230 is cut to a predetermined size, the positive electrode layer 210 and the negative electrode layer 220 around the electrode 230 are scraped, and the SUS foil is exposed to form a seal layer.

  The unit cell was formed by laminating the positive electrode and the negative electrode so as to face each other with the electrolyte layer 240 interposed therebetween. By repeating the stacking as described above, a power generation element 160 in which seven cell units as shown in FIG. 2 are stacked is formed. The positive electrode terminal electrode and the negative electrode terminal electrode are prepared by applying the positive electrode layer 210 or the negative electrode layer 220 only on one side.

  The electrolyte layer 240 is preferably formed of a gel solute. By using a gel electrolyte as the electrolyte layer 240, it is possible to prevent leakage, and to prevent a liquid junction, which is a problem peculiar to the dual electrode type secondary battery, to realize a highly reliable stacked battery. Can do.

  Here, the difference between the all solid polymer electrolyte and the polymer gel electrolyte will be described. A polymer gel electrolyte is an all-solid polymer electrolyte such as PEO (polyethylene oxide) containing an electrolyte solution usually used in a lithium ion battery. Moreover, what hold | maintained electrolyte solution in polymer frame | skeleton which does not have lithium ion conductivity like PVDF, PAN, and PMMA also corresponds to a polymer gel electrolyte. The ratio of the polymer constituting the polymer gel electrolyte to the electrolyte solution is wide. When 100% of the polymer is an all solid polymer electrolyte and 100% of the electrolyte solution is a liquid electrolyte, all of the intermediates correspond to the polymer gel electrolyte. On the other hand, the all solid electrolytes include all electrolytes having Li ion conductivity such as polymers or inorganic solids. In the present invention, the solid electrolyte includes all of polymer gel electrolyte, all solid polymer electrolyte, and inorganic solid electrolyte.

  In addition, it is preferable to use a lithium-transition metal composite oxide for the positive electrode active material and a carbon or lithium-transition metal composite oxide for the negative electrode active material, so that a bipolar battery excellent in capacity and output characteristics can be obtained. Can be realized.

  After the battery element 160 is formed so that the seven cells are stacked, the peripheral portion of each electrode 230 is covered with a heat-sealing seal member 260, and as shown in FIG. ) 270, first three-way heat-sealing, and then vacuum-sealing the last side to vacuum-seal the battery element 160 and seal the electrolyte layer 240.

  The heat-sealing seal member 260 is preferably a resin material made of polyolefin (polypropylene, polyethylene), polyester (PET, PEN), polyimide, or polyamide. By using these materials, it is possible to insulate without adversely affecting the battery. In addition, these materials are electrochemically stable materials within the operating potential of the battery, and reliable insulation is possible without adversely affecting the battery.

  In the bipolar battery 100 of the present embodiment, the heat-sealing seal member 260 particularly includes a non-heat-sealing portion 290 at the edge portion 280 of the current collector 200. Thereby, even if a heat press is performed to heat-seal the sealing member 260, the sealing member 260 in the edge portion 280 of the current collector 200 is not heated, and the sealing portion in the edge portion 280 is not broken. . Therefore, since the peripheral portion of the bipolar electrode 230 can be completely sealed, it is possible to prevent electrolyte leakage and short circuit due to contact between current collectors, which are problems when the bipolar battery 100 is constructed.

  Specifically, when performing the heat press 270 of the heat sealing member 260, the length and width of the heat bar 330 are set so that the position where the press is applied does not reach the edge portion 280 of the current collector 200, as shown in FIG. The non-heat-sealed portion 290 is formed by setting and adopting a seal structure that does not cause heat-sealing at the edge portion 280 of the current collector 200. In FIG. 4, reference numeral 340 denotes a heat fusion part.

  Alternatively, a seal structure as shown in FIG. 5 can be employed. That is, the heat-sealing seal member 260 is formed larger than the current collector 200 so that the end of the heat-sealing seal member 260 extends outward from the current collector 200. Then, the edge portion 280 of the current collector 200 is removed, and the sealing member is thermally welded to at least one of the positive electrode side and the negative electrode side of the bipolar electrode 230. Further, heat sealing is performed at a position beyond the edge portion 280 so that the seal portion extended outside the current collector 200 does not reach the edge portion 280 of the current collector 200. By adopting such a seal structure, the non-thermal fusion part 290 exists in the edge part 280 of the current collector 200, and the seal part in the edge part 280 is not broken. Further, it becomes possible to fuse the seal member 260 to each bipolar electrode 230 one by one, and the reliability of the seal can be improved.

  Further, as shown in FIG. 6, the heat-sealing seal member 260 may have a multilayer structure in which a non-heat-sealing layer 370 having a high melting point is sandwiched between heat-sealing layers 360 having a low melting point. By disposing the non-thermal fusion layer 370 at a position corresponding to the edge portion 280 of the current collector 200, the non-thermal fusion portion 290 can be formed on the edge portion 280, and the heating press 270 is performed. However, since the non-thermal fusion layer 370 is not melted, the seal member 260 at the edge portion 280 of the current collector 200 is not heated, and the seal portion at the edge portion 280 is not broken. A short circuit due to contact between bodies can be prevented.

  Further, as shown in FIG. 7, a non-thermally fused portion 290 can be formed by providing a non-thermally fused insulator 380 at the edge portion 280 of the current collector 200. That is, by providing a non-heat-bonded insulator 380 at the edge portion 280 of the current collector 200, the electrodes are insulated from each other. Is not heated, a non-thermally fused portion 290 is formed, the seal portion at the edge portion 280 is not broken, and leakage of electrolyte and short circuit due to contact between current collectors can be prevented.

  As this insulator 380, for example, an insulating material different from that of the heat-sealing seal member 260, a resin material having a rigidity higher than that of the heat-sealing seal member, a ceramic material, or a metal foil that has been surface-treated with an insulating material, etc. Can be adopted. In particular, by using a material having rigidity higher than that of the heat-sealing seal member in the peripheral portion of the bipolar electrode, the insulator can have a skeleton (frame) function, and the rigidity of the bipolar battery is improved.

  Furthermore, not only the insulator 380 is disposed at a position corresponding to the edge portion 280 of the current collector 200, but as shown in FIG. 8, the heat-sealing seal member 260 is provided between the heat-sealing layers 360 having a low melting point. It may have a multilayer structure with a non-heat-bonding layer 370 having a high melting point interposed therebetween. Thus, by disposing the insulator 380 at a position corresponding to the edge portion 280 of the current collector 200 and using the heat-sealing seal member 260 having a multilayer structure, the non-heat-sealing portion 290 is provided on the edge portion 280. It is easy to form. Accordingly, even when the heating press 270 is performed, the seal member 260 at the edge portion 280 of the current collector 200 is not heated, the seal portion at the edge portion 280 is not broken, and leakage of the electrolyte or contact between the current collectors occurs. Can prevent short circuit.

  The lowermost negative electrode terminal pole of the power generation element 160 is connected to the negative electrode tab 120B, and the uppermost positive electrode terminal electrode is connected to the positive electrode tab 120A. Since the power generating element 160 shown in FIG. 2 has seven unit cells connected in series, a voltage seven times that of the unit cells appears between the positive electrode tab 120A and the negative electrode tab 120B.

  In the present embodiment, the power generation element 160 is configured with a set of seven unit cells. However, the number of stacked unit cells constituting the power generation element 160 is not limited to this embodiment.

  As shown in FIG. 1, in the present embodiment, the power generation element 160 is covered with a flexible exterior material (exterior case) 180, and its periphery is heat-sealed. 160 is sealed with the positive electrode tab 120A and the negative electrode tab 120B pulled out.

  By using a flexible material as the constituent material of the exterior material 180, the exterior material 180 can be easily deformed without being broken due to a pressure difference between the inside and the outside. Any material can be used for the exterior material 180 as long as it is electrically stable without allowing electrolyte or gas to permeate and is chemically stable even if the electrolyte is present inside. However, examples of the material include synthetic resins such as polyethylene, polypropylene, and polycarbonate. In particular, in consideration of the heat sealing property of the exterior material 180 and the reduction of the air contact possibility of the electrolyte, it is desirable to select a laminate film in which a metal foil such as aluminum is coated with a synthetic resin.

  This is because, if a laminate film made of a metal foil and a synthetic resin film is used as the exterior material 180, the resin film can be easily deformed, so that hydrostatic pressure can be applied. This is because the permeability difference can be lowered and the pressure difference between the inside and outside of the exterior material 180 can be maintained for a long time.

  The bipolar batteries described above are connected in series or in parallel to form an assembled battery module 250 (see FIG. 9), and a plurality of assembled battery modules 250 are connected in series or in parallel to form an assembled battery. 300 can also be formed. FIG. 9 shows a plan view (FIG. A), a front view (FIG. B), and a side view (FIG. C) of the assembled battery 300. The assembled battery module 250 is electrically connected like a bus bar. The assembled battery modules 250 are stacked in a plurality of stages using the connection jig 310. How many bipolar batteries 100 are connected to create the assembled battery module 250 and how many assembled battery modules 250 are stacked to create the assembled battery 300 depend on the vehicle (electric vehicle) to be mounted. It may be determined according to the battery capacity and output.

  Thus, the assembled battery 300 in which a plurality of assembled battery modules 250 are connected in series and parallel can obtain high capacity and high output, and the reliability of each assembled battery module 250 is high. The long-term reliability of 300 can be maintained. Further, even if some of the assembled battery modules 250 fail, repair can be performed by simply replacing the failed part.

  In order to mount the assembled battery 300 on the electric vehicle 400, it is mounted under the seat at the center of the vehicle body of the electric vehicle 400 as shown in FIG. This is because if it is installed under the seat, the interior space and the trunk room can be widened. The place where the assembled battery 300 is mounted is not limited to the position under the seat, but may be a lower part of the rear trunk room or an engine room in front of the vehicle. The electric vehicle 400 using the assembled battery 300 as described above has high durability and can provide sufficient output even when used for a long period of time. Furthermore, it is possible to provide electric vehicles and hybrid vehicles that are excellent in fuel efficiency and running performance.

  In the present invention, not only the assembled battery 300 but also only the assembled battery module 250 may be mounted depending on the usage, or the assembled battery 300 and the assembled battery module 250 may be mounted in combination. Also good. Further, as the vehicle on which the assembled battery or the assembled battery module of the present invention can be mounted, the above-described electric vehicle and hybrid car are preferable, but are not limited thereto. For example, the present invention can be applied to other vehicles such as trains.

  Examples of the bipolar battery according to the present invention will be described below, but the present invention is not limited to these examples.

First, the production of the power generation element 160 common to Examples 1 to 4 and the comparative example will be described. As described above, the power generating element 160 includes the bipolar electrode 230 in which the positive electrode layer 210 is formed on one surface of the current collector 200 and the negative electrode layer 220 is formed on the other surface, and between the bipolar electrodes. A plurality of electrolyte layers 240 for performing ion exchange are alternately stacked, and a plurality of unit cells are stacked.
<Formation of electrode>
First, a positive electrode slurry is applied to one side of a stainless steel foil (SUS foil), which is a current collector having a thickness of 20 μm, and dried to form a positive electrode layer. The positive electrode slurry is a mixture of 85 wt% LiMn ₂ O ₄ as a positive electrode active material, 5 wt% acetylene black as a conductive additive, 10 wt% PVDF as a binder, and NMP as a slurry viscosity adjusting solvent.
Next, a negative electrode slurry is apply | coated to the opposite surface of the electrical power collector (SUS foil) which apply | coated the positive electrode layer, and it is made to dry, and a negative electrode layer is formed. The negative electrode slurry is a mixture of 90 wt% hard carbon as a negative electrode active material, 10 wt% PCDF as a binder, and NMP as a slurry viscosity adjusting solvent.

  A bipolar electrode was formed by forming a positive electrode layer and a negative electrode layer on both sides of the current collector (SUS foil). The completed bipolar electrode was cut into a size of 140 mm × 90 mm. Further, in order to form a seal layer in the peripheral portion of the electrode 10 mm, the positive electrode layer and the negative electrode layer were scraped to expose the SUS foil. As a result, a bipolar electrode having a 120 mm × 70 mm electrode portion and a seal margin of 10 mm in the peripheral portion was produced.

In addition, what applied the positive electrode layer or the negative electrode layer only to the single side | surface was produced for the positive electrode terminal electrode and the negative electrode terminal electrode.
<Formation of gel electrolyte>
Polypropylene non-woven fabric 50 μm, ion conductive polymer matrix precursor with an average molecular weight of 7500-9000 monomer solution (copolymer of polyethylene oxide and polypropylene oxide) 10 wt%, electrolyte solution PC + EC (1: 1) 90 wt %, 1.0M LiPF ₆ , and a pregel solution composed of a polymerization initiator (BDK) were immersed, sandwiched between quartz glass substrates, irradiated with ultraviolet rays for 15 minutes to crosslink the precursor, and a gel polymer electrolyte layer was obtained. .
<Formation of power generation elements>
The positive electrode and the negative electrode were stacked so as to face each other with the gel electrolyte interposed therebetween, thereby forming a unit cell. This was repeated to form a battery element such that, for example, five cell units were stacked.

Hereinafter, Examples 1 to 4 and a comparative example will be described.
Example 1
In Example 1, after forming a battery element so that five layers of single cells are stacked, the peripheral part of each electrode is covered with a heat-sealing seal member, and heat pressing (heat and pressure) is performed from above and below to form a battery. The element was vacuum sealed to seal the electrolyte layer.

  When performing this heat press, the length and width of the heat bar were set so that the position where the press was applied did not reach the edge portion of the current collector, and a seal structure was formed so that the edge portion was not thermally fused. The pressing conditions were a pressure of 0.2 MPa and a heating temperature of 160 ° C. for 5 seconds. Ni tabs were welded to the positive electrode end electrode and the negative electrode end electrode of this power generation element, and sealed with a laminate pack to form a bipolar battery.

Ten such bipolar batteries were produced.
(Example 2)
In Example 2, the heat sealing member was set to protrude 10 mm outside the electrode projection surface. Thereafter, heat pressing (heat and pressure) was performed from above and below, and the sealing member and the peripheral part on the positive electrode side were heat-sealed.

  When performing this heat press, the length and width of the heat bar were set so that the position where the press was applied did not reach the edge portion of the current collector, and a seal structure was formed so that the edge portion was not thermally fused. The pressing conditions were a pressure of 0.2 MPa and a heating temperature of 160 ° C. for 5 seconds. Five layers of bipolar electrodes with seal members thus produced were laminated.

  After that, a seal structure was formed by heat-sealing so that the seal portion protruding from the current collector did not reach the edge portion of the current collector, and the laminate was completed. The pressing conditions were a pressure of 0.2 MPa and a heating temperature of 160 ° C. for 5 seconds. Ni tabs were welded to the positive electrode end electrode and the negative electrode end electrode of this power generation element, and sealed with a laminate pack to form a bipolar battery.

Ten such bipolar batteries were produced.
(Example 3)
In Example 3, bipolar was used in the same manner as in Example 1 except that a three-layer film of PE (melting point: 98 ° C.) / Modified PP (melting point: 180 ° C.) / PE (melting point: 98 ° C.) was used as the sealing member. A battery was produced.

Ten such bipolar batteries were produced.
Example 4
In Example 4, bipolar was used in the same manner as in Example 2 except that a three-layer film of PE (melting point: 98 ° C.) / Modified PP (melting point: 180 ° C.) / PE (melting point: 98 ° C.) was used as the sealing member. A battery was produced.

Ten such bipolar batteries were produced.
(Reference example)
In the reference example, a bipolar battery was manufactured in the same manner as in Example 1 except that heat was applied to the heat-sealing seal member at the edge portion of the current collector.
Ten such bipolar batteries were produced.
<Evaluation>
About the said Examples 1-4 and the reference example, each 10 batteries were charged and evaluation was tried. The charging conditions were constant current charging (CC) up to 21 V with a current of 0.5 C, then charging (CV) with a constant voltage, and charging for a total of 5 hours.

  As for the bipolar battery of the reference example, eight of the ten batteries caused a voltage drop, and could not maintain the fully charged voltage of 21V.

  However, in the bipolar batteries of Examples 1 to 4, all the batteries continued to maintain the voltage for one month or longer. Therefore, it has been found that when the seal structure that does not apply heat to the heat-sealing seal member is employed at the edge portion of the current collector, it is difficult to cause a short circuit.

  Next, the bipolar batteries of Examples 1 to 4 were vibrated for a long time, and then voltage measurement was performed to confirm the voltage maintenance rate. This vibration test was performed at a temperature of 70 ° C. by applying a monotonous vibration with an amplitude of 3 mm and 50 Hz for 200 hours in a direction perpendicular to a firmly fixed battery. The voltage after the vibration test was measured for each of the ten batteries of Examples 1 to 4, and the voltage maintenance rate was confirmed.

  In Example 1, the average voltage before the test of 10 batteries was 20.6V, and the average after the test was 18.8V. Therefore, the average voltage maintenance ratio was 91.26%.

  In Example 2, the average voltage before the test of 10 batteries was 20.5V, and the average after the test was 19.9V. Therefore, the average voltage maintenance ratio was 97.07%.

  In Example 3, the average voltage before the test of 10 batteries was 20.6V, and the average after the test was 20.1V. Therefore, the average voltage maintenance ratio was 97.57%.

  In Example 4, the average voltage before the test of 10 batteries was 20.6V, and the average after the test was 20.4V. Therefore, the average voltage maintenance ratio was 99.03%.

  From the above result, the result with a high voltage maintenance factor was shown in order of Example 4, Example 3, Example 2, and Example 1. Although the detailed reason for this result is not clear, it is considered that the sealing strength and battery rigidity are good.

  By using the bipolar battery and the assembled battery according to the present invention as, for example, a drive source for an electric vehicle or a hybrid electric vehicle, a long-life and highly reliable vehicle can be realized. Also, the present invention can be applied to other vehicles such as trains.

It is an external view of the bipolar battery according to the present embodiment. It is a schematic block diagram inside the bipolar battery which concerns on this Embodiment. It is the schematic of the condition which has given the heat press to the heat sealing | fusion seal member. It is a figure explaining the seal structure in this Embodiment. It is a figure explaining the seal structure in this Embodiment. It is a figure explaining the seal structure in this Embodiment. It is a figure explaining the seal structure in this Embodiment. It is a figure explaining the seal structure in this Embodiment. It is a schematic block diagram of an assembled battery. It is a figure which shows the state with which the assembled battery was mounted in the vehicle.

Explanation of symbols

100 bipolar battery,
120A positive electrode tab,
120B negative electrode tab,
160 power generation elements,
180 exterior material,
200 current collector,
210 positive electrode layer,
220 negative electrode layer,
230 bipolar electrodes,
240 electrolyte layer,
250 battery module,
260 heat-sealing seal member,
270 heating press,
280 edge part,
290 non-thermal fusion part,
300 battery packs,
310 connection jig,
330 heat bar,
340 heat fusion part,
360 heat sealing layer,
370 non-thermal fusion layer,
380 insulator,
400 Electric car.

Claims (14)

A bipolar electrode having a positive electrode layer formed on one side of the current collector and a negative electrode layer formed on the other side, and an electrolyte layer that performs ion exchange between the bipolar electrodes are alternately stacked to generate power. A bipolar battery having a heat-sealing seal member that forms an element and prevents electrolyte leakage in the periphery of the electrode,
The bipolar battery, wherein the heat-sealing seal member includes a non-heat-sealing portion at an edge portion of the current collector.   The bipolar battery according to claim 1, wherein the non-heat-sealed portion is formed without heating the heat-sealing seal member.   An end portion of the heat-sealing seal member extends outward from the current collector, and the seal member is heat-sealed to at least one of the positive electrode side and the negative electrode side of the electrode. 3. The bipolar battery according to claim 2, wherein a seal portion extending outward from the electric body is heat-sealed so as not to reach an edge portion of the current collector.   The bipolar battery according to claim 1, wherein the non-thermal fusion part is formed by providing a non-thermal fusion insulator at an edge part of the current collector.   The bipolar battery according to claim 4, wherein the insulator is an insulating material different from that of the heat-sealing seal member.   The bipolar battery according to claim 4, wherein the insulator is a resin material having rigidity higher than that of the heat-sealing seal member.   The bipolar battery according to claim 4, wherein the insulator is a ceramic material.   The bipolar battery according to claim 4, wherein the insulator is a metal foil that is surface-treated with an insulating material.   The bipolar battery according to any one of claims 1 to 8, wherein the heat-sealing seal member is a multilayer structure seal member in which a layer having a high melting point is sandwiched between layers having a low melting point.   The said heat sealing | fusion sealing member is a resin material which consists of polyolefin (polypropylene, polyethylene), polyester (PET, PEN), a polyimide, or polyamide, The any one of Claims 1-9 characterized by the above-mentioned. Bipolar battery.   The positive electrode layer is made of a positive electrode active material made of a lithium-transition metal composite oxide, and the negative electrode layer is made of a negative electrode active material made of carbon or a lithium-transition metal composite oxide. The bipolar battery according to any one of 10.   The bipolar battery according to claim 1, wherein gel electrolyte is used for the electrolyte layer.   An assembled battery comprising a plurality of the bipolar batteries according to claim 1 connected to each other.   A vehicle comprising the bipolar battery according to claim 1 or the assembled battery according to claim 13 as a power source.

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