JP5790368B2 - Bipolar battery - Google Patents

Description

  The present invention relates to a bipolar battery having a bipolar electrode.

  In the prior art of Patent Document 1, a part of the current collector is a resin layer in order to reduce the weight of the battery. Since the barrier property against ions is not sufficient with only the resin layer, the metal layer is arranged in the middle of the resin layers on both sides of the current collector, and the deterioration of the current collector can be suppressed.

JP 2010-92664 A

  However, in the event of an abnormality such as an internal short circuit, a metal layer having a low electrical resistance is present in the current collector, so that current concentrates on the short circuit part where the short circuit has occurred and an abnormal state such as heat generation of the battery occurs.

  The present invention has been made paying attention to such a conventional problem, and an object thereof is to prevent an abnormal state of a battery from being caused by an internal short circuit.

Bipolar battery according to an aspect of the present invention includes a power generating element housed in the outer body and the outer Sokarada, power generation element comprises a a laminated bipolar electrode and the electrolyte layer. Bi-pole electrode comprises a positive electrode, a negative electrode, and a current collector arranged between the positive electrode and the negative electrode. Current collector comprises a first laminar part and a second laminar portion which can spatially separated in the product layer direction. The first layered portion includes a conductive first resin layer in contact with the positive electrode of the bipolar electrode and a metal layer bonded thereto. The second layered portion includes a conductive second resin layer in contact with the negative electrode of the bipolar electrode. And a 1st resin layer and a 2nd resin layer can move so that it may space apart in the lamination direction. The metal layer is disposed between the first resin layer and the second resin layer, and the metal layer of the first layered portion and the second resin layer of the second layered portion are spatially separated in the stacking direction. Get away.

  According to the present invention, the short-circuit current is suppressed, and an abnormal state of the battery can be prevented from being caused by the internal short circuit.

It is a longitudinal cross-sectional view which shows the bipolar battery which concerns on each embodiment. It is a partial cross section figure at the normal time of the electric power generation element (laminated body) which concerns on 1st embodiment. It is a partial cross section figure at the time of abnormality of the electric power generation element (laminated body) which concerns on 1st embodiment. It is a partial cross section figure which shows the flow of the short circuit current at the time of abnormality of the electric power generation element which concerns on a prior art, and an equivalent circuit. It is a partial cross section figure which shows the flow of the short circuit current at the time of abnormality of the electric power generation element which concerns on 1st embodiment, and an equivalent circuit. In the equivalent circuit, when the electrical resistance is large, the symbol of the resistance is greatly shown. It is a partial cross section figure at the time of abnormality of the electric power generation element which concerns on 2nd embodiment. It is a partial cross section figure which shows the flow of the short circuit current at the time of abnormality of the electric power generation element which concerns on 2nd embodiment, and an equivalent circuit. In the equivalent circuit, when the electrical resistance is large, the symbol of the resistance is greatly shown. It is a partial cross section figure at the time of abnormality of the electric power generation element which concerns on 3rd embodiment. It is a partial cross section figure which shows the flow of the short circuit current at the time of abnormality of the electric power generation element which concerns on 3rd embodiment, and an equivalent circuit. In the equivalent circuit, when the electrical resistance is large, the symbol of the resistance is greatly shown. The relationship between the surface pressure and the electrical resistance (contact resistance) between the 1st metal layer and 2nd metal layer of the electrical power collector which concern on 3rd embodiment is shown. It is a partial cross section figure which shows the structure of the bipolar battery which concerns on a comparative example. It is a figure which shows battery internal resistance at the time of charging / discharging (normal time) of 3rd embodiment and a comparative example.

  Hereinafter, embodiments for carrying out the present invention will be described in more detail with reference to the drawings.

<First embodiment>
FIG. 1 is a longitudinal sectional view showing a bipolar battery according to each embodiment. The bipolar battery 1 includes a power generation element 10 that generates power, an electrode tab 20 that is a terminal that inputs and outputs current from the outside of the battery, and an exterior body (case) 30 that houses the power generation element 10. The power generation element 10 includes a bipolar electrode 11, an electrolyte layer (separator) 12 disposed between adjacent bipolar electrodes 11, and a seal 13. The power generation element 10 is a laminated body in which a plurality of bipolar electrodes 11 and a plurality of electrolyte layers 12 are laminated. Hereinafter, although the case where the bipolar battery 1 is a lithium ion battery will be described, other types of batteries may be used.

  The bipolar electrode 11 includes a current collector 41, a positive electrode 42, and a negative electrode 43. The positive electrode 42 is formed on one surface (the upper surface in FIG. 1) of the current collector 41. The negative electrode 43 is formed on the opposite surface of the current collector 41 (the lower surface in FIG. 1). Therefore, the current collector 41 is disposed between the positive electrode 42 and the negative electrode 43. Usually, the positive electrode 42 and the negative electrode 43 are formed on the surface of the current collector 41 by coating. The positive electrode 42 includes, as a positive electrode active material, a material that releases ions (here, lithium ions) during charging and occludes ions during discharging. The negative electrode 43 includes, as a negative electrode active material, a material that occludes ions (here, lithium ions) during charge and releases ions during discharge. The kind of ion is not particularly limited.

An example of the positive electrode active material is a lithium-transition metal composite oxide that is a composite oxide of a transition metal and lithium. Specifically, Li · Co-based composite oxide such as LiCoO _2, Li · Ni-based composite oxide such as LiNiO _2, Li · Mn-based composite oxide such as spinel LiMn ₂ O _4, Li · such LiFeO ₂ Fe-based composite oxides and those obtained by replacing some of these transition metals with other elements. Such a positive electrode active material may be used alone or in a mixture of two or more.

Examples of the negative electrode active material include carbon materials such as natural graphite, artificial graphite, carbon black, activated carbon, carbon fiber, coke, soft carbon, or hard carbon, metals such as Si and Sn, TiO, Ti ₂ O ₃ , TiO ₂ , or metal oxides such as SiO ₂ , SiO, SnO ₂ , and composite oxides of lithium and transition metals such as Li _4/3 Ti _5/3 O ₄ or Li ₇ MnN.

The electrolyte layer 12 is, for example, a microporous separator that holds an electrolytic solution. Examples of the separator include a microporous resin film made of polyethylene resin or polypropylene resin. The electrolyte layer 12 is in contact with the positive electrode 42 on one surface, and is in contact with the negative electrode 43 on the surface opposite to the positive electrode 42. The electrolytic solution is a nonaqueous electrolytic solution in which a solute of lithium salt is dissolved in an organic liquid solvent. For example, an electrolytic solution obtained by dissolving LiPF ₆ as a lithium salt in a solvent obtained by mixing ethylene carbonate (EC) and diethyl carbonate (DEC) may be used.

  The seal 13 is disposed between the upper and lower current collectors 41 and around the positive electrode 42, the negative electrode 43, and the electrolyte layer 12. The seal 13 prevents contact between the current collectors and a short circuit at the end of the unit cell layer. Examples of the material of the seal 13 include acrylic resin, urethane resin, epoxy resin, polyethylene resin, polypropylene resin, polyimide resin, rubber, nylon resin, and the like.

  The electrode tab 20 includes a metal portion 21 that abuts against the power generation element (laminated body) 10. The metal part 21 may be an elastic member that can be deformed depending on whether an external force is applied. One end of the electrode tab 20 is exposed to the outside of the exterior body 30. The electrode tab 20 is formed of, for example, aluminum, copper, titanium, nickel, stainless steel (SUS), or an alloy thereof. The positive electrode tab 20 and the negative electrode tab 20 may be made of the same material or different materials. Further, different materials may be laminated in multiple layers.

  The exterior body 30 houses the power generation element 10. The exterior body 30 is flexible and deformable. Various materials can be considered for the outer package 30. For example, the outer package 30 is a sheet material of a polymer-metal composite laminate film in which a metal (including an alloy) such as aluminum, stainless steel, nickel, or copper is covered with a polypropylene film. After housing the power generating element 10, the exterior body 30 is joined to the periphery by thermal fusion. In the assembled state shown in FIG. 1, the interior of the exterior body 30 is lower than atmospheric pressure and is almost vacuum.

  Since the exterior body 30 is sealed in a state where the internal pressure is lower than the atmospheric pressure, for example, in a substantially vacuum state, a differential pressure (atmospheric pressure) between the outside and the inside of the exterior body 30 acts on the exterior body 30. For this reason, in the normal state of the bipolar battery 1, the exterior body 30 applies an external force to the power generation element 10 via the metal portion 21 of the electrode tab 20 and presses the power generation element 10 on the outermost surface in the stacking direction.

  The configuration of the current collector 41, which is a feature of this embodiment, will be described below with reference to FIGS.

  FIG. 2 is a partial cross-sectional view of the power generation element (laminated body) 10. The current collector 41 is disposed between the first resin layer 101 having conductivity, the second resin layer 102 having conductivity, and the first resin layer 101 and the second resin layer 102. A metal layer 103. The first resin layer 101 is in contact with the positive electrode 42 of the bipolar electrode 11. In the present embodiment, the first resin layer 101 and the positive electrode 42 are joined by applying the positive electrode 42 to the first resin layer 101. The second resin layer 102 is in contact with the negative electrode 43 of the bipolar electrode 11. In the present embodiment, the second resin layer 102 and the negative electrode 43 are joined by applying the negative electrode 43 to the second resin layer 102.

  The first resin layer 101 and the second resin layer 102 are formed using a resin to which a conductive filler (metal component) is added. In the present embodiment, polyimide is used as the resin constituting the first resin layer 101, and polyolefin is used as the resin constituting the second resin layer 102. The first resin layer 101 and the second resin layer 102 may be formed of a conductive polymer resin without adding a conductive filler (metal component).

  Examples of the conductive filler include conductive carbon, a metal filler made of a metal such as silver or aluminum, or an alloy thereof. Alternatively, examples of the conductive filler include a filler in which the surface of a non-conductive filler such as a resin is coated with a metal such as silver or aluminum or an alloy thereof.

  As shown in FIG. 3, the current collector 41 includes a first layered portion 41a (first plate-like portion) and a second layered portion 41b (second plate) that can move spatially away from each other in the stacking direction. Shaped portion). The first layered portion 41a is composed of a first resin layer 101 and a metal layer 103 bonded thereto. The second layered portion 41 b is composed of the second resin layer 102.

  The metal layer 103 is formed by sputtering or vapor deposition of metal (here, copper) on the surface opposite to the surface on which the positive electrode 42 is formed on the first resin layer 101. Therefore, the first resin layer 101 and the metal layer 103 are physically and / or chemically bonded. In addition, as a material of the metal layer 103, inexpensive and highly conductive copper is used, but other metals (such as aluminum) may be used. The second resin layer 102 is only formed on the metal layer 103 on the side opposite to the negative electrode 43 after being formed, and is physically and / or chemically bonded to the second resin layer 102 and the metal layer 103. It has not been. Therefore, the first layered portion 41a and the second layered portion 41b are spatially separated between the metal layer 103 and the second resin layer 102 to form a gap, and can be made out of contact with each other. FIG. 3 shows the configuration of the current collector 41 at the time of abnormality, and the metal layer 103 and the second resin layer 102 are in contact with each other in a normal state.

  The stacking direction in which the differential pressure between the outside and inside of the exterior body 30 decreases and the power applied to the power generation element 10 from the exterior body 30 when there is an abnormality in which the pressure inside the exterior body 30 increases due to damage to the exterior body 30 or the like. The external force decreases. In this case, the metal layer 103 and the second resin layer 102 are spatially separated (not in contact), and a gap may be generated between them. In particular, when the vacuum inside the exterior body 30 is broken and the differential pressure becomes zero, the exterior body 30 expands, so that the metal layer 103 and the second resin layer 102 can be spatially separated.

  In consideration of the possibility that the resin layer may be deformed and lifted, the size of the exterior body 30 (particularly the length in the stacking direction) is the size of the power generation element 10 (particularly the stacking direction) after the vacuum inside the exterior body 30 is released. (Length in the direction) may be larger. By doing so, the contact between the first layered portion 41a (metal layer 103) and the second layered portion 41b is easily released. Further, when the exterior body 30, the metal portion 21 of the electrode tab 20, and the power generation element 10 are bonded or bonded, when the exterior body 30 expands, the outermost surface of the power generation element 10 is separated from the exterior body 30. By being pulled, the contact between the first layered portion 41a (metal layer 103) and the second layered portion 41b is easily released.

-Effect-
Below, the effect of this embodiment is demonstrated collectively. A typical example in which an internal short circuit occurs in the bipolar battery 1 is a case where a metallic nail 200 having conductivity is pierced into the bipolar battery 1. In this case, in the configuration of the conventional technique, in the current collector 41, the first layered portion 41a (metal layer 103) and the second layered portion 41b (second resin layer 102) are joined and not separated. When an abnormality occurs, a short-circuit current flows as shown in FIG. 4, and the battery generates heat.

  However, in the present embodiment, the current collector 41 constituting the bipolar electrode 11 includes the first layered portion 41a and the second layered portion 41a that can be spatially separated in the stacking direction when the pressure inside the exterior body 30 increases. The layered portion 42b is provided. Therefore, as shown in FIG. 5, when the pressure inside the exterior body 30 increases due to damage to the exterior body 30, in the current collector 41, the first layered portion 41 a and the second layered portion 42 b Between them, the contact resistance (electrical resistance) increases. And it can prevent that the short circuit current of an internal short circuit reduces significantly, and abnormal states, such as heat_generation | fever of a battery, arise.

  The first layered portion 41a of the current collector 41 includes a conductive first resin layer 101 in contact with the positive electrode 42 of the bipolar electrode 11, and the second layered portion 41b of the current collector is a bipolar electrode. The second resin layer 102 is in contact with the negative electrode 43 of the eleventh electrode. And when the pressure inside the exterior body 30 increases, the 1st resin layer 101 and the 2nd resin layer 102 move so that it may space apart in the lamination direction. In this case, the electrical resistance between the first resin layer 101 and the second resin layer 102 is increased, so that the short circuit current can be significantly suppressed, and an abnormal state such as heat generation of the battery is easily caused by the short circuit current. Can be prevented.

  The first layered portion 41a of the current collector 41 includes a first resin layer 101 and a metal layer 103 bonded thereto. The metal layer 103 of the first layered portion 41a and the second resin layer 102 of the second layered portion 41b can be spatially separated in the stacking direction. At the time of an abnormality in which the pressure inside the exterior body 30 increases, the opposing positive electrode 42 and negative electrode 43 can be easily insulated, and a short-circuit current can be suppressed. When the metal layer 103 is made of copper, the internal resistance during normal operation can be kept small, and the cost of the battery can be reduced.

<Second embodiment>
Below, with reference to FIG. 6, the structure of the electrical power collector 41 which is the characteristics of 2nd embodiment is demonstrated. As in the first embodiment, the current collector 41 includes a first layered portion 41a and a second layered portion 41b that can move spatially away from each other in the stacking direction. However, unlike the first embodiment, the first layered portion 41 a is composed of the first resin layer 101. The second layered portion 41b is composed of a second resin layer 102 and a metal layer 103 bonded thereto. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

  The metal layer 103 is formed on the second resin layer 102 on the surface opposite to the surface on which the negative electrode 43 is formed by sputtering or vapor deposition of metal (here, copper). Therefore, the second resin layer 102 and the metal layer 103 are physically and / or chemically joined. The metal layer 103 is disposed between the first resin layer 101 and the second resin layer 102. However, after the first resin layer 101 is formed, the first resin layer 101 is merely overlapped with the metal layer 103 on the side opposite to the positive electrode 42, and is physically and / or chemically overlapped with the first resin layer 101 and the metal layer 103. It is not joined to. Accordingly, the first layered portion 41a and the second layered portion 41b are spatially separated between the metal layer 103 and the first resin layer 101 to form a gap, and can be made non-contact with each other. FIG. 6 shows the configuration of the current collector 41 at the time of abnormality, and the metal layer 103 and the first resin layer 101 are in contact with each other at normal times.

  When the pressure inside the exterior body 30 increases due to damage to the exterior body 30 or the like, the differential pressure between the outside and inside of the exterior body 30 decreases, and the stacking direction applied from the exterior body 30 to the power generation element 10 increases. External force decreases. In this case, the metal layer 103 and the first resin layer 101 are spatially separated (not in contact), and a gap may be generated between them. In particular, when the vacuum inside the exterior body 30 is broken and the differential pressure becomes zero, the exterior body 30 expands, so that the metal layer 103 and the first resin layer 101 can be spatially separated.

  According to the second embodiment, the second layered portion 41b of the current collector 41 includes the second resin layer 102 and the metal layer 103 bonded thereto, and the metal layer 103 is formed with the first resin layer 101 and the first resin layer 101. It is disposed between the two resin layers 102. Then, the metal layer 103 of the second layered portion 41b and the first resin layer 101 of the first layered portion 41a can be spatially separated in the stacking direction. For this reason, when the pressure inside the exterior body 30 increases, it becomes possible to easily insulate the positive electrode 42 and the negative electrode 43 facing each other, and the short-circuit current can be suppressed.

<Third embodiment>
Below, with reference to FIG. 8, the structure of the electrical power collector 41 which is the characteristics of 3rd embodiment is demonstrated. As in the first embodiment, the current collector 41 includes a first layered portion 41a and a second layered portion 41b that can move spatially away from each other in the stacking direction. However, unlike the first embodiment, the first layered portion 41a is composed of the first resin layer 101 and the first metal layer 103 bonded thereto. The second layered portion 41b includes a second resin layer 102 and a second metal layer 104 bonded thereto. The first metal layer 103 of the first layered portion 41a and the second metal layer 104 of the second layered portion 41b are disposed between the first resin layer 101 and the second resin layer 102 and laminated. Can be spatially separated in direction. FIG. 8 shows the configuration of the current collector 41 at the time of abnormality, and the first metal layer 103 and the second metal layer 104 are in contact with each other in a normal state. Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

  The first metal layer 103 is formed on the surface of the first resin layer 101 opposite to the surface on which the positive electrode 42 is formed by sputtering or vapor deposition of metal (here, copper), The resin layer 101 and the metal layer 103 are joined. The second metal layer 104 is formed on the second resin layer 102 on the surface opposite to the surface on which the negative electrode 43 is formed by sputtering or vapor deposition of metal (here, copper). The resin layer 102 and the second metal layer 104 are joined. However, the first metal layer 103 and the second metal layer 104 only overlap and are not joined. Accordingly, the first layered portion 41a and the second layered portion 41b are spatially separated between the first metal layer 103 and the second metal layer 104 to form a gap and are not in contact with each other. Can do.

  When the pressure inside the exterior body 30 increases due to damage to the exterior body 30 or the like, the differential pressure between the outside and inside of the exterior body 30 decreases, and the stacking direction applied from the exterior body 30 to the power generation element 10 increases. External force decreases. In this case, the first metal layer 103 and the second metal layer 104 are spatially separated (not in contact), and a gap may be generated between them. In particular, when the internal vacuum of the exterior body 30 is broken and the differential pressure becomes zero, the exterior body 30 expands, so that the first metal layer 103 and the second metal layer 104 can be spatially separated.

  According to the third embodiment, the first layered portion 41 a of the current collector 41 includes the first resin layer 101 and the first metal layer 103 bonded thereto, and the second layered portion of the current collector 41. 41b is provided with the 2nd resin layer 102 and the 2nd metal layer 104 joined to this. The first metal layer 103 of the first layered portion and the second metal layer 104 of the second layered portion are disposed between the first resin layer 101 and the second resin layer 102 and laminated. Can be spatially separated in direction. Therefore, when the pressure inside the exterior body 30 increases, it becomes possible to easily insulate the positive electrode 42 and the negative electrode 43 facing each other and suppress a short-circuit current.

  FIG. 10 shows the relationship between the surface pressure and the electrical resistance (contact resistance) acting between the first metal layer 103 and the second metal layer 104 of the current collector 41 according to the third embodiment. When the pressure inside the exterior body 30 increases, the first metal layer 103 of the first layered portion 41a moves away from the second metal layer 104 of the second layered portion 41b. When the surface pressure acting between the first metal layer 103 and the second metal layer 104 is changed from a normal pressure of 0.1 Mpa to an abnormal pressure of 0 Mpa, the electric resistance (contact resistance) increases by 10 times or more. To do. Thus, in a normal time when the vacuum inside the exterior body 30 is maintained, the differential pressure between the inside and the exterior of the exterior body 30 is 0.1 MPa corresponding to atmospheric pressure, and the first metal layer 103 and the second metal layer 103 The metal layer 104 is in surface contact and has low electrical resistance, and can be charged and discharged. When the vacuum inside the exterior body 30 is released, the contact area between the first metal layer 103 and the second metal layer 104 is reduced, the electrical resistance is increased 10 times or more, and the short circuit current is suppressed. Is done.

  Further, according to the third embodiment, the first metal layer 103 of the first layered portion 41 a and the second metal layer 104 of the second layered portion 41 b are maintained in the vacuum inside the outer package 30. In a normal state, the metal is in contact. For this reason, in normal times, the contact resistance between the first metal layer 103 and the second metal layer 104 is small, and the internal resistance can be kept low.

  FIG. 11 shows a structure of a bipolar battery according to the prior art as a comparative example. The bipolar battery of FIG. 11 corresponds to the bipolar battery 1 of the first embodiment in which the second resin layer 102 and the metal layer 103 of the first layered portion 41a are joined by hot pressing. FIG. 12 shows the battery internal resistance during charging / discharging (normal time) of the third embodiment and the comparative example. The battery internal resistance at the time of charging / discharging (normal time) of the third embodiment and the comparative example is the same. As described above, in the third embodiment, even if the metal layer of the current collector 41 is physically separated, the internal resistance of the bipolar battery 1 is not increased at normal times.

  Without being limited to the embodiments described above, various modifications and changes are possible within the scope of the technical idea, and it is obvious that these are also included in the technical scope of the present invention.

  For example, the first resin layer 101, the second resin layer 102, and the metal layer 103 are first, second, and third layered portions, and the current collector 41 is separated from each other. Three layered portions may be provided. Without the metal layer 103, the current collector 41 may be constituted only by the separable first resin layer 101 and second resin layer 102. Even if the bipolar battery is a battery other than the lithium ion battery, the present invention can be applied.

DESCRIPTION OF SYMBOLS 1 Bipolar battery 10 Electric power generation element 11 Bipolar electrode 12 Electrolyte layer (separator)
13 Seal 20 Electrode Tab 30 Exterior Body (Case)
41 current collector 41a first layered portion 41b second layered portion 42 positive electrode
43 Negative electrode
101 First resin layer
102 Second resin layer
103 metal layer (first metal layer)
104 Second metal layer
200 nails

Claims (4)

A bipolar battery including an exterior body and a power generation element housed in the exterior body, the power generation element including a stacked bipolar electrode and an electrolyte layer,
The bipolar electrode comprises a positive electrode, a negative electrode, and a current collector disposed between the positive electrode and the negative electrode,
The current collector includes a first laminar part and a second laminar portion which can spatially separated in the product layer direction,
The first laminar portion of the current collector is provided with a positive electrode in contact with the conductive first resin layer and a metal layer bonded thereto the bipolar electrode,
The second layered portion of the current collector includes a conductive second resin layer in contact with the negative electrode of the bipolar electrode,
The first resin layer and the second resin layer can move spatially apart in the stacking direction ,
Before Symbol metal layer is disposed between the second resin layer and the first resin layer,
Wherein said metal layer of the first layered portion, the second and the second resin layer of the layered portion is a bi-pole battery you characterized in that could spatially separated in the stacking direction. A bipolar battery including an exterior body and a power generation element housed in the exterior body, the power generation element including a stacked bipolar electrode and an electrolyte layer,
The bipolar electrode comprises a positive electrode, a negative electrode, and a current collector disposed between the positive electrode and the negative electrode,
The current collector includes a first laminar part and a second laminar portion which can spatially separated in the product layer direction,
The first layered portion of the current collector includes a conductive first resin layer in contact with a positive electrode of the bipolar electrode,
The second layered portion of the current collector includes a conductive second resin layer in contact with the negative electrode of the bipolar electrode and a metal layer bonded thereto.
The first resin layer and the second resin layer can move spatially apart in the stacking direction ,
Before Symbol metal layer is disposed between the second resin layer and the first resin layer,
Wherein a second of said metal layer of the layered portion, said a first of said first resin layer of the layered portion is a bi-pole battery you characterized in that could spatially separated in the stacking direction. A bipolar battery including an exterior body and a power generation element housed in the exterior body, the power generation element including a stacked bipolar electrode and an electrolyte layer,
The bipolar electrode comprises a positive electrode, a negative electrode, and a current collector disposed between the positive electrode and the negative electrode,
The current collector includes a first layered portion and a second layered portion that can be spatially separated in the stacking direction ,
The first laminar portion of the current collector is provided with a positive electrode in contact with the conductive first resin layer of a first metal layer bonded thereto the bipolar electrode,
The second layered portion of the current collector comprises a conductive second resin layer in contact with the negative electrode of the bipolar electrode and a second metal layer bonded thereto.
The first resin layer and the second resin layer can move spatially apart in the stacking direction ,
The first metal layer of the first layered portion and the second metal layer of the second layered portion are disposed between the first resin layer and the second resin layer, twin electrode type battery you characterized in that it could spatially separated in the stacking direction. The bipolar battery according to any one of claims 1 to 3 , wherein the metal layer is made of copper.

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