JP2013114796A - Bipolar battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bipolar battery capable of restraining malfunction of an entire battery.SOLUTION: The bipolar battery comprises: plural electrode bodies having positive electrodes and negative electrodes, and electrolyte layers arranged between the positive electrodes and the negative electrodes; a positive electrode collector connected to the positive electrodes; a negative electrode collector connected to the negative electrodes; and a series collector arranged between the two laminated electrode bodies and connected to the positive electrodes constituting one electrode body and the negative electrodes constituting the other electrode body. A conductive deformation material deformed according to a temperature is connected to ends of at least one or more collectors selected from a group of the positive electrode collector, the negative electrode collector and the series collector. The conductive deformation material is arranged so that it extends in an outer peripheral direction of the collector, and that the deformed deformation material is in contact with the adjacent other collectors in a lamination direction and the conductive deformation material connected to the other collectors.

Description

  The present invention relates to a bipolar battery having a current collector in which a positive electrode active material is disposed on one surface side and a negative electrode active material is disposed on the other surface side.

  A lithium ion secondary battery has the characteristics that it has a higher energy density than other secondary batteries and can operate at a high voltage. For this reason, it is used as a secondary battery that can be easily reduced in size and weight in information equipment such as a mobile phone, and in recent years, there is an increasing demand for large motive power such as for electric vehicles and hybrid vehicles.

  A lithium ion secondary battery includes a positive electrode and a negative electrode, and an electrolyte layer disposed between them. Examples of the electrolyte used for the electrolyte layer include non-aqueous liquid and solid substances. It has been. When a liquid electrolyte (hereinafter referred to as “electrolytic solution”) is used, the electrolytic solution easily penetrates into the positive electrode and the negative electrode. Therefore, an interface between the active material contained in the positive electrode or the negative electrode and the electrolytic solution is easily formed, and the performance is easily improved. However, since the widely used electrolyte is flammable, it is necessary to mount a system for ensuring safety. On the other hand, when a solid electrolyte that is flame retardant (hereinafter referred to as “solid electrolyte”) is used, the above system can be simplified. Therefore, development of a lithium ion secondary battery in a form provided with a layer containing a solid electrolyte (hereinafter referred to as a “solid electrolyte layer”) is in progress.

  As a technique related to such a lithium ion secondary battery, for example, in Patent Document 1, a positive electrode in which a positive electrode active material layer is formed on the surface of a current collector, a separator, and a negative electrode active material layer on the surface of the current collector are disclosed. There is disclosed a bipolar lithium ion secondary battery having a battery element in which a formed negative electrode is laminated in this order, and at least one positive electrode active material layer and a separator including a heat-resistant material.

JP 2007-335294 A

  In a bipolar battery as disclosed in Patent Document 1, a plurality of electrode bodies having a positive electrode and a negative electrode and an electrolyte layer disposed between the positive electrode and the negative electrode are electrically connected in series via a conductive material. It is connected. Therefore, even if, for example, one electrode body among the plurality of electrode bodies is destroyed, there is a possibility that the current does not flow and the entire bipolar battery cannot be used.

  Then, this invention makes it a subject to provide the bipolar battery which can suppress the malfunction of the whole battery.

  As a result of intensive studies, the present inventors have developed a conductive deformable material that deforms depending on temperature on a current collector of a bipolar battery having a plurality of electrode bodies electrically connected in series via the current collector. If any of the electrode bodies is abnormally heated, the conductive deformable material is deformed and short-circuited, and the current is bypassed to the abnormally heated electrode body, so that any electrode body It has been found that even when abnormality occurs, it is possible to prevent malfunction of the entire bipolar battery. The present invention has been completed based on this finding.

In order to solve the above problems, the present invention takes the following means. That is,
The present invention includes a positive electrode and a negative electrode, a plurality of electrode bodies having an electrolyte layer disposed between the positive electrode and the negative electrode, a positive electrode current collector connected to the positive electrode, and a negative electrode current collector connected to the negative electrode. A positive electrode current collector comprising: a positive electrode that is disposed between two stacked electrode bodies, and that is connected to a positive electrode that constitutes one electrode body; and a negative electrode that constitutes the other electrode body. A conductive deformable material that deforms according to temperature is connected to an end of at least one current collector selected from the group consisting of a negative electrode current collector and a series current collector, The conductive deformable material that extends in the outer peripheral direction of the current collector is in contact with another current collector adjacent to the stacking direction or the conductive deformable material connected to the other current collector. In other words, the bipolar battery is arranged.

  Here, “the conductive deformable material is arranged so as to extend in the outer peripheral direction of the current collector” means that the deformed conductive deformable material does not come into contact with the positive electrode or the negative electrode, for example, as shown in FIG. In addition, it means that the conductive deformation materials 5a and 5b are disposed outside the positive electrode and the negative electrode when viewed from the stacking direction of the positive electrode, the electrolyte layer, and the negative electrode. The “stacking direction” refers to a direction in which the positive electrode current collector, the electrode body, the series current collector, and the negative electrode current collector are stacked. Further, “another current collector adjacent in the stacking direction” refers to a current collector connected to the deformed conductive deformable material and a current collector adjacent to the stacking direction.

  The conductive deformable material that deforms depending on the temperature is arranged so as to be in contact with another current collector or the conductive deformable material connected to the other current collector at the time of deformation. When an abnormally heated electrode body heats up, current is routed around only the electrode body that has heated up abnormally (the electrode body that has heated up abnormally is removed from the series circuit), and the current flow path that flows through the part that does not heat up abnormally Can be maintained. By adopting such a configuration, a situation in which an abnormally heated electrode body is destroyed, a situation in which heat is propagated to another electrode body having no abnormality, and a situation in which another electrode body having no abnormality is also destroyed are avoided. Therefore, even if an abnormality occurs in any of the electrode bodies, it is possible to prevent malfunction of the entire bipolar battery.

  In the present invention, the positive electrode current collector is connected to a conductive deformable material that bends toward the positive electrode connected to the positive electrode current collector, and the negative electrode current collector is connected to the negative electrode current collector. A conductive deformation material that bends to the side is connected, and the series current collector includes a conductive deformation material that bends to the positive electrode side connected to the series current collector, and a conductive property that bends to the negative electrode side connected to the series current collector. It is preferable that the sexually deformable material is connected. By adopting such a configuration, even if any of the electrode bodies included in the plurality of electrode bodies has an abnormality, the conductive deformable material is deformed so that only the electrode body in which the abnormality has occurred can be bypassed and a current can flow. Therefore, it becomes easy to prevent malfunction of the entire bipolar battery.

  ADVANTAGE OF THE INVENTION According to this invention, the bipolar battery which can suppress the malfunction of the whole battery can be provided.

1 is a side view illustrating a bipolar battery 10. 1 is a top view illustrating a bipolar battery 10. FIG. It is a side view explaining bipolar battery 10 '.

  The present invention will be described below with reference to the drawings. In the following drawings, description of an exterior body etc. is abbreviate | omitted and a part of repeated code | symbol may be abbreviate | omitted. In addition, the form shown below is an illustration of this invention and this invention is not limited to the form shown below. In the following description, “%” means mass% unless otherwise specified.

  FIG. 1 is a side view illustrating a bipolar battery 10 of the present invention. FIG. 2 is a top view illustrating the bipolar battery 10. In FIG. 1, only a part of the bipolar battery 10 is extracted and shown.

  As shown in FIG. 1, the bipolar battery 10 includes a plurality of electrode bodies 1, 1,..., And the positive electrode current collector 2, the negative electrode current collector 3, or the series current collectors 4, 4, ... and electrode bodies 1, 1, ... are alternately laminated. The electrode body 1 includes a positive electrode 1a and a negative electrode 1c, and an electrolyte layer 1b disposed between the positive electrode 1a and the negative electrode 1c. In the bipolar battery 10, the positive electrode 1 a is arranged on the upper side in the drawing of FIG. 1, and the negative electrode 1 c is arranged on the lower side of the drawing in FIG. 1, and the positive electrode 1 a of the electrode body 1 arranged at the top in the stacking direction. The positive electrode current collector 2 is connected to the negative electrode 1c of the electrode body 1 arranged at the bottom in the stacking direction, and the negative electrode current collector 3 is connected to the negative electrode current collector 3 respectively. As shown in FIGS. 1 and 2, a conductive deformation material 5a that is curved toward the positive electrode 1a connected to the positive electrode current collector 2 is connected to the end of the positive electrode current collector 2 at a high temperature. A conductive deformation material 5b that is curved toward the negative electrode 1c connected to the negative electrode current collector 3 is connected to the end of the negative electrode current collector 3 at a high temperature. Further, at the end of the series current collectors 4, 4,..., The conductive deformation material 5 a that curves toward the positive electrodes 1 a, 1 a,... Connected to the series current collectors 4, 4,. Are connected to the negative electrodes 1c, 1c,... Connected to the series current collectors 4, 4,..., Respectively, at high temperatures.

  FIG. 3 is a side view for explaining the bipolar battery 10 ′ in which the abnormality occurs in only one electrode body 1 and the electrode body 1 in which the abnormality has occurred (hereinafter referred to as “electrode body 1 x”) generates heat. is there. FIG. 3 corresponds to a view of the bipolar battery 10 ′ viewed from the left side of FIG. 1.

  When an abnormality occurs in the electrode body 1 constituting the bipolar battery 10 and heat is generated, and the bipolar battery 10 is in a state of a bipolar battery 10 ′ having the heated electrode body 1 x, the series current collector connected to the electrode body 1 x The temperature of the bodies 4 and 4 rises. When the temperature of the series current collector 4 connected to the positive electrode 1a of the electrode body 1x rises, the conductive deformation material 5a connected to the series current collector 4 becomes the positive electrode 1a side of the electrode body 1x (in FIG. 3). When the temperature of the series current collector 4 that is curved to the lower side of the paper and becomes the conductive deformable material 5a ′ and connected to the negative electrode 1c of the electrode body 1x rises, it is connected to the series current collector 4 The conductive deformable material 5b is curved toward the negative electrode 1c side (upper side of the drawing in FIG. 3) of the electrode body 1x to become a conductive deformable material 5b ′. In the bipolar battery 10 ′, the conductive deformable material 5 a ′ and the conductive deformable material 5 b ′ are in contact with each other. When the curved conductive deformable material 5a ′ and the curved conductive deformable material 5b ′ are brought into contact, the electrode body 1x is bypassed, and an electric current is passed through the contacted conductive deformable material 5a ′ and the conductive deformable material 5b ′. Can do. When a current is passed in this way, no current flows through the electrode body 1x, so the voltage of the bipolar battery 10 'is lower than the voltage of the bipolar battery 10. However, unlike the conventional bipolar battery in which the current cannot flow when the electrode bodies included in the plurality of electrode bodies connected in series are destroyed, the bipolar battery 10 continues the current even if the electrode body 1x is destroyed. Malfunction of the entire battery can be avoided. Further, according to the bipolar battery 10, since it is possible to prevent the current from flowing through the electrode body 1x, the situation in which the electrode body 1x is destroyed and the other electrode bodies 1, 1,. It is also possible to avoid the situation of propagation. Therefore, according to the present invention, it is possible to provide the bipolar battery 10 capable of suppressing the malfunction of the entire battery. In a conventional bipolar battery not provided with a conductive deformable material, the state of each electrode body is monitored in order to prevent a situation in which the entire battery becomes malfunctioning even when an abnormality occurs in the cell. If an attempt is made to provide a monitoring circuit, the structure becomes complicated, for example, wiring is required for all the current collectors, and there is a concern about a decrease in energy density and an increase in cost. On the other hand, according to the bipolar battery 10, only the conductive deformation materials 5a and 5b are connected to the current collectors (the positive electrode current collector 2, the negative electrode current collector, and the series current collectors 4, 4,...). Therefore, it is possible to suppress the complexity of the structure, the decrease in energy density, and the increase in cost.

  In the bipolar battery 10, the conductive deformable material 5 a is connected to the positive electrode current collector 2, and the conductive deformable material 5 b is connected to the negative electrode current collector 3, and all the series current collectors 4, 4,. In addition, two conductive deformation materials (conductive deformation material 5a and conductive deformation material 5b) are connected to each other. By adopting such a configuration, even if an abnormality occurs in any of the electrode bodies 1 included in the plurality of electrode bodies 1, 1,... Since the conductive deformable members 5a and 5b can be deformed, it is possible to obtain the bipolar battery 10 that can easily prevent malfunction of the entire battery.

In the bipolar battery 10, the positive electrode active material contained in the positive electrode 1a may be appropriately selected according to the metal ions that move between the positive electrode 1a and the negative electrode 1c. For example, when the bipolar battery 10 is a lithium ion battery, examples of the positive electrode active material include layered active materials such as lithium cobaltate (LiCoO ₂ ) and lithium nickelate (LiNiO ₂ ), and olivine-type lithium iron phosphate (LiFePO 4). ₄ ) and other known positive electrode active materials such as spinel type active materials such as spinel type lithium manganate (LiMn ₂ O ₄ ) can be used as appropriate. When the bipolar battery 10 is a sodium ion battery, a known positive electrode active material such as sodium ferrate (NaFeO ₂ ) or fluorinated sodium iron phosphate (Na ₂ FePO ₄ F) is appropriately used as the positive electrode active material. Can do. In addition, when the bipolar battery 10 is a potassium ion battery, a magnesium ion battery, or a calcium ion battery, a positive electrode active material that can be used for each battery can be appropriately used as the positive electrode active material.

  The shape of the positive electrode active material can be, for example, particulate or thin film. The average particle diameter (D50) of the positive electrode active material is, for example, preferably from 1 nm to 100 μm, and more preferably from 10 nm to 50 μm. Moreover, the content of the positive electrode active material in the positive electrode 1a is not particularly limited, but is preferably 40% or more and 99% or less, for example.

From the viewpoint of making it easy to prevent an increase in battery resistance by making it difficult to form a high resistance layer at the interface between the positive electrode active material and the solid electrolyte, in the present invention, the positive electrode active material is an ion conductive oxide. It is preferably coated. Examples of the lithium ion conductive oxide that coats the positive electrode active material include a general formula Li _x AO _y (where A is B, C, Al, Si, P, S, Ti, Zr, Nb, Mo, Ta, and the like). Or W and x and y are positive numbers.) Specifically, Li ₃ BO ₃ , LiBO ₂ , Li ₂ CO ₃ , LiAlO ₂ , Li ₄ SiO ₄ , Li ₂ SiO ₃ , Li ₃ PO ₄ , Li ₂ SO ₄ , Li ₂ TiO ₃ , Li ₄ Ti ₅ Examples include O ₁₂ , Li ₂ Ti ₂ O ₅ , Li ₂ ZrO ₃ , LiNbO ₃ , Li ₂ MoO ₄ , Li ₂ WO _{4 and the} like. The lithium ion conductive oxide may be a complex oxide. As the composite oxide covering the positive electrode active material, any combination of the above lithium ion conductive oxides can be employed. For example, Li ₄ SiO ₄ —Li ₃ BO ₃ , Li ₄ SiO ₄ —Li ₃ PO ₄ etc. can be mentioned. Moreover, the ion conductive oxide should just coat | cover at least one part of a positive electrode active material, and may coat | cover the positive electrode active material whole surface. In addition, the thickness of the ion conductive oxide covering the positive electrode active material is, for example, preferably from 0.1 nm to 100 nm, and more preferably from 1 nm to 20 nm. The thickness of the ion conductive oxide can be measured using, for example, a transmission electron microscope (TEM).

The positive electrode 1a only needs to contain at least a positive electrode active material. In addition, a known solid electrolyte, a binder that binds the positive electrode active material and another material, a conductive material that improves conductivity, and the like are included. It may be contained. For example, when the bipolar battery 10 is a lithium ion battery, as the solid electrolyte that can be contained in the positive electrode 1a, _Li 3 PS ₄ and, Li ₂ S and _P 2 _{S 5} mixture of _Li 2 was produced S it can be exemplified -P ₂ S sulfide-based solid electrolytes such as _5. When the positive electrode 1a contains a solid electrolyte, the form of the solid electrolyte is not particularly limited. In addition to a crystalline solid electrolyte, an amorphous solid electrolyte, glass ceramic, polyethylene oxide (PEO), or polyvinylidene fluoride is used. -A polymer electrolyte such as hexafluoropropylene copolymer (PVdF-HFP) may be used. Examples of the binder that can be contained in the positive electrode 1a include styrene butadiene rubber (SBR) and polyvinylidene fluoride (PVdF). As the conductive material that can be contained in the positive electrode 1a, In addition to carbon materials such as vapor grown carbon fiber and carbon black, metal materials that can withstand the environment when the battery is used can be exemplified. Although content of the solid electrolyte in the positive electrode 1a is not specifically limited, For example, it is preferable to set it as 10% or more and 90% or less. Further, when the positive electrode 1a is produced through a process in which the slurry-like composition prepared by dispersing the positive electrode active material or the like in a liquid is applied to the positive electrode current collector 2 or the series current collector 4 or the like, Examples of the liquid in which the liquid is dispersed include heptane and a nonpolar solvent can be preferably used. The thickness of the positive electrode 1a is, for example, preferably from 0.1 μm to 1 mm, and more preferably from 1 μm to 100 μm.

  Moreover, as an electrolyte to be contained in the electrolyte layer 1b, a known electrolyte that can be used for a bipolar battery can be appropriately used. As such an electrolyte, the said solid electrolyte etc. which can be contained in the positive electrode 1a can be illustrated. In addition, the electrolyte layer 1b may contain a binder that binds the solid electrolytes from the viewpoint of developing plasticity. Examples of such a binder include styrene butadiene rubber (SBR). However, in order to easily increase the output, the electrolyte layer 1b is included from the viewpoint of preventing the excessive aggregation of the solid electrolyte and enabling the formation of the electrolyte layer 1b having a uniformly dispersed solid electrolyte. The binder is preferably 5% or less. In addition, when the electrolyte layer 1b is manufactured through a process of applying the slurry-like composition prepared by dispersing the solid electrolyte or the like in a liquid to the positive electrode 1a or the negative electrode 1c, as a liquid for dispersing the solid electrolyte or the like, A heptane etc. can be illustrated and a nonpolar solvent can be used preferably. The content of the solid electrolyte material in the electrolyte layer 1b is, for example, preferably 60% or more, more preferably 70% or more, and particularly preferably 80% or more. The thickness of the electrolyte layer 1b varies greatly depending on the configuration of the battery. For example, the thickness is preferably 0.1 μm or more and 1 mm or less, and more preferably 1 μm or more and 100 μm or less.

The negative electrode 1c only needs to contain a negative electrode active material. In addition, the negative electrode 1c contains a solid electrolyte, a binder that binds the negative electrode active material and another material, a conductive material that improves conductivity, and the like. May be. As the negative electrode active material contained in the negative electrode 1c, for example, a known negative electrode active material capable of occluding and releasing metal ions can be used as appropriate. As such a negative electrode active material, a carbon active material, an oxide active material, a metal active material, etc. can be illustrated. The carbon active material is not particularly limited as long as it contains carbon, and examples thereof include mesocarbon microbeads (MCMB), highly oriented graphite (HOPG), hard carbon, and soft carbon. Examples of the oxide active material include Nb ₂ O ₅ , Li ₄ Ti ₅ O ₁₂ , and SiO. Examples of the metal active material include In, Al, Si, and Sn. Further, a lithium-containing metal active material may be used as the negative electrode active material. The lithium-containing metal active material is not particularly limited as long as it is an active material containing at least Li, and may be Li metal or Li alloy. Examples of the Li alloy include an alloy containing Li and at least one of In, Al, Si, and Sn.

  The shape of the negative electrode active material can be, for example, particulate or thin film. The average particle diameter (D50) of the negative electrode active material is, for example, preferably from 1 nm to 100 μm, and more preferably from 10 nm to 30 μm. Moreover, the content of the negative electrode active material in the negative electrode 1c is not particularly limited, but is preferably 40% or more and 99% or less, for example.

  Furthermore, the negative electrode 1c can contain the solid electrolyte that can be contained in the positive electrode 1a. In addition, the negative electrode 1c may contain a binder for binding the negative electrode active material and the solid electrolyte, and a conductive material for improving conductivity. Examples of the binder and conductive material that can be contained in the negative electrode 1c include the binder and conductive material that can be contained in the positive electrode 1a. When the conductive material is contained in the negative electrode 1c, the amount of the conductive material is set to 10% or more of the weight of the negative electrode including the conductive material from the viewpoint of easily exerting the effect of improving the electronic conductivity, From the standpoint of facilitating the decrease, the weight of the negative electrode including the conductive material is 80% or less. The addition amount of the conductive material is preferably 20% to 60% of the weight of the negative electrode including the conductive material. In the case where the negative electrode 1c is manufactured through a process in which a slurry-like composition prepared by dispersing the negative electrode active material or the like in a liquid is applied to the negative electrode current collector 3 or the series current collector 4 or the like, Examples of the liquid in which the liquid is dispersed include heptane and a nonpolar solvent can be preferably used. Further, the thickness of the negative electrode 1c is, for example, preferably from 0.1 μm to 1 mm, and more preferably from 1 μm to 100 μm. In the present invention, the mass ratio of the positive electrode 1a and the negative electrode 1c is not particularly limited, but from the viewpoint of sufficiently accepting ions moving between the positive electrode 1a and the negative electrode 1c, the capacity of the negative electrode 1c is positive electrode 1a. It is preferable to increase the capacity.

  The positive electrode current collector 2, the negative electrode current collector 3, and the series current collector 4 can be made of a known metal that can be used as a current collector of a bipolar battery. As such a metal, a metal containing one or more elements selected from the group consisting of Cu, Ni, Al, V, Au, Pt, Mg, Fe, Ti, Co, Cr, Zn, Ge, and In. Materials can be exemplified. From the viewpoint of easily increasing the volume energy density, etc., in the bipolar battery 10, the thickness of the positive electrode current collector 2, the negative electrode current collector 3, and the series current collector 4 is preferably 10 μm or less.

  In addition, as the conductive deformable members 5a and 5b, plate-like members in which a plurality of metals having different linear expansion coefficients, in which the amount of warpage changes with a temperature change, can be used. Specifically, a bimetal obtained by laminating two kinds of metals having different linear expansion coefficients, a trimetal obtained by laminating three kinds of metals having different linear expansion coefficients, and the like can be used as the conductive deformation materials 5a and 5b. . From the viewpoint of making the conductive deformable materials 5a and 5b easy to deform, it is preferable to use a metal having a small linear expansion coefficient as one metal among a plurality of metals constituting the conductive deformable materials 5a and 5b. preferable. Examples of the metal having a small linear expansion coefficient include amber steel (Invar steel). The term “amber steel” as used herein is a concept including an amber steel that is an Fe—Ni alloy, a super amber steel that is an Fe—Ni—Co alloy, and a stainless amber steel that is an Fe—Co—Cr alloy. May be used. From the viewpoint of availability and cost, it is more preferable to use amber steel that is an Fe—Ni alloy. Further, in a scene where corrosion resistance is required, such as when vacuum-depositing a corrosive material, stainless amber steel may be preferable. The second metal laminated with the one metal constituting the conductive deformation material 5a, 5b can withstand the environment when the bipolar battery 10 is used, and the bimetal has a higher coefficient of thermal expansion. A known metal material that can be used as the metal can be appropriately used. Examples of such second metal include nickel, Fe—Ni—Mn alloy, Fe—Ni—Cr alloy and the like.

  In the bipolar battery 10, the same member can be used for the conductive deformation members 5a and 5b. When used as the conductive deformable material 5a, the metal having a relatively small linear expansion coefficient may be disposed so as to face the lower side of the drawing in FIG. What is necessary is just to arrange | position so that a metal with a small coefficient of linear expansion may face the upper surface of the paper of FIG.

  In the bipolar battery 10, the method of connecting the conductive deformable materials 5 a and 5 b to the positive electrode current collector 2, the negative electrode current collector 3, and the series current collector 4 is not particularly limited. The connection may be made by a known method typified by welding or the like, or may be made using a known adhesive or the like.

  In the above description of the present invention, the form in which the curved conductive deformation material 5a 'and the curved conductive deformation material 5b' are brought into contact with each other has been exemplified. However, the bipolar battery of the present invention is not limited to this form. In the bipolar battery of the present invention, the deformed conductive deformation body is brought into contact with another current collector adjacent to the current collector to which the deformed conductive deformation body is connected in the stacking direction. Is also possible.

  In the above description of the present invention, the conductive deformable materials 5a and 5b that are deformed according to temperature are used as current collectors (positive electrode current collector 2, negative electrode current collector 3, serial current collectors 4, 4,...). Although the connected form was illustrated, the bipolar battery of the present invention is not limited to the form. The bipolar battery of the present invention can be configured such that a part of the current collector functions as a conductive deformable material by joining a metal having a coefficient of linear expansion different from that of the current collector to the current collector. is there. In the case of such a configuration, for example, a current collector having a surface in which the lamination direction is a normal direction (lamination surface) is larger than that of the positive electrode and the negative electrode, and the current collector is disposed on the outer edge of the current collector. What is necessary is just to join the metal from which a coefficient of linear expansion differs from a body. For example, instead of the conductive deformation materials 5a and 5b, a metal having a smaller linear expansion coefficient than the current collector is joined to the current collector (the lower surface side of the positive electrode current collector 2, the upper surface of the negative electrode current collector 3). Are joined to the upper surface side and the lower surface side of the current collectors 4, 4,...), A bipolar battery having the same effect as the bipolar battery 10 can be obtained.

DESCRIPTION OF SYMBOLS 1, 1x ... Electrode body 1a ... Positive electrode 1b ... Electrolyte layer 1c ... Negative electrode 2 ... Positive electrode collector 3 ... Negative electrode collector 4 ... Series collector 5a, 5b, 5a ', 5b' ... Conductive deformation material 10, 10 '... bipolar battery

Claims (2)

A plurality of electrode bodies having a positive electrode and a negative electrode, and an electrolyte layer disposed between the positive electrode and the negative electrode;
A positive electrode current collector connected to the positive electrode;
A negative electrode current collector connected to the negative electrode;
Arranged between the two stacked electrode bodies, the positive electrode constituting one electrode body, and a series current collector connected to the negative electrode constituting the other electrode body,
A conductive deformable material that deforms according to temperature is connected to an end of at least one current collector selected from the group consisting of the positive electrode current collector, the negative electrode current collector, and the series current collector. And
The conductive deformable material extends in the outer peripheral direction of the current collector, and the deformed conductive deformable material is connected to another current collector adjacent to the stacking direction or the other current collector. A bipolar battery arranged to be in contact with the conductive deformation material. The positive electrode current collector is connected to the conductive deformable material bent to the positive electrode side connected to the positive electrode current collector,
The negative electrode current collector is connected to the conductive deformable material bent to the negative electrode side connected to the negative electrode current collector,
The series current collector includes the conductive deformation material bent to the positive electrode side connected to the series current collector, and the conductive deformation material bent to the negative electrode side connected to the series current collector. The bipolar battery according to claim 1, which is connected.

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