Battery

Abstract

The present invention relates to a battery having a plurality of series bodies including a first series body and a second series body. Each of the plurality of series bodies has a plurality of electrode bodies, and has at least one intermediate current collector. The plurality of series bodies are electrically connected in parallel with each other. In each of the plurality of series bodies, the plurality of electrode bodies are electrically connected in series with each other via the intermediate current collector, and the intermediate current collectors of the first series body and the second series body are directly electrically connected to each other.

Description

Technical Field

[0001] The present invention relates to a battery. Background Art

[0002] A technique of electrically connecting a plurality of bipolar batteries in parallel with each other is disclosed in Japanese Unexamined Patent Application Publication No. 2014-116156. In other words, the battery disclosed in Japanese Unexamined Patent Application Publication No. 2014-116156 includes a plurality of series-connected bodies, which are obtained by electrically connecting a plurality of electrode bodies (which may also be referred to as a plurality of unit cells) in series with each other, and the battery is formed by electrically connecting the plurality of series-connected bodies in parallel with each other. In addition, a technique of electrically connecting at least two unit cells in parallel with each other inside a bipolar battery is disclosed in Japanese Unexamined Patent Application Publication No. 2018-028978. Summary of the Invention

[0003] In the battery disclosed in Japanese Unexamined Patent Application Publication No. 2014-116156, if a part of a plurality of electrode bodies undergoes abnormal capacity reduction, the voltage deviation in the series-connected body including the electrode body becomes significant, and accordingly, the battery may deteriorate rapidly. It is difficult to suppress such rapid deterioration by using the technique disclosed in Japanese Unexamined Patent Application Publication No. 2018-028978.

[0004] An aspect of the present invention provides a battery, wherein

[0005] it has a plurality of series-connected bodies including a first series-connected body and a second series-connected body,

[0006] each of the plurality of series-connected bodies has a plurality of electrode bodies,

[0007] each of the plurality of series-connected bodies has at least one intermediate current collector,

[0008] the plurality of series-connected bodies are electrically connected in parallel with each other,

[0009] in each of the plurality of series-connected bodies, the plurality of electrode bodies are electrically connected in series with each other via the intermediate current collector,

[0010] the intermediate current collector of the first series-connected body and the intermediate current collector of the second series-connected body are directly electrically connected to each other.

[0011] In an aspect of the present invention, it may also be that at least one of the plurality of series-connected bodies has a bipolar structure.

[0012] In an aspect of the present invention, it may also be that the intermediate current collector includes a resin and a conductive material.

[0013] The battery in an aspect of the present invention may also be that in the first series-connected body, the number of the plurality of electrode bodies electrically connected in series with each other via the intermediate current collector is 2 or 3.

[0014] In the embodiment of the present invention, it is also possible that the plurality of tandem bodies are housed inside one outer package.

[0015] In the embodiment of the present invention,

[0016] the plurality of tandem bodies may also be stacked on one another,

[0017] in each of the plurality of tandem bodies, the plurality of electrode bodies may also be stacked on one another,

[0018] the stacking direction of the plurality of tandem bodies may also be the same as the stacking direction of the plurality of electrode bodies.

[0019] The battery in the embodiment of the present invention may also be an all-solid-state battery.

[0020] According to the embodiment of the present invention, even if a part of the plurality of electrode bodies undergoes abnormal capacity reduction, it is easy to suppress the voltage deviation in the tandem body including the electrode body. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Hereinafter, the features, advantages, and technical and industrial significance of the exemplary embodiments of the present invention will be described with reference to the drawings, in which the same reference numerals indicate the same elements, and in which:

[0022] Figure 1 is a diagram schematically showing the structure of a battery.

[0023] Figure 2 is a diagram schematically showing the structure of a battery.

[0024] Figure 3 is a diagram schematically showing the structure of a battery.

[0025] Figure 4 is a diagram schematically showing the structure of a battery.

[0026] Figure 5 is a diagram showing the voltage deviation in the battery of the embodiment.

[0027] Figure 6 is a diagram showing the voltage deviation in the battery of the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0028] As Figures 1 to 3As shown, the battery 100 of the embodiment has a plurality of tandem bodies 10 including a first tandem body 10 and a second tandem body 10. In addition, each of the plurality of tandem bodies 10 has a plurality of electrode bodies 1. In addition, each of the plurality of tandem bodies 10 has at least one intermediate current collector 3. In addition, the plurality of tandem bodies 10 are electrically connected in parallel with each other. In addition, in each of the plurality of tandem bodies 10, the plurality of electrode bodies 1 are electrically connected in series with each other via the intermediate current collector 3. Moreover, the intermediate current collector 3 of the first tandem body 10 and the intermediate current collector 3 of the second tandem body 10 are directly electrically connected to each other.

[0029] 1. Tandem body

[0030] As Figure 1 and Figure 2 shown, the battery 100 has a plurality of tandem bodies 10 including a first tandem body 10 and a second tandem body 10. Each of the plurality of tandem bodies 10 has a plurality of electrode bodies 1 and also has at least one intermediate current collector 3. In each of the tandem bodies 10, the number of the plurality of electrode bodies 1 may be two or more, which may be two, three, or four or more. In addition, in each of the tandem bodies 10, the number of the intermediate current collectors 3 may be one or more, which may be one, two, or three or more.

[0031] 2. Electrode body

[0032] As Figure 1 and Figure 2 shown, each electrode body 1 can constitute a unit cell. As Figure 1 shown, each electrode body 1 may have a positive electrode active material layer 1a, a negative electrode active material layer 1b, and an electrolyte layer 1c. The positive electrode active material layer 1a, the negative electrode active material layer 1b, and the electrolyte layer 1c can be easily obtained by known forming methods such as coating, transfer printing, or stamping.

[0033] 2.1 Positive electrode active material layer

[0034] The positive electrode active material layer 1a can include at least a positive electrode active material. When the battery 100 is a all-solid-state battery, the positive electrode active material layer 1a may also optionally include a solid electrolyte, a binder, a conductive additive, etc. in addition to the positive electrode active material. In addition, when the battery 100 is an electrolyte-based battery, the positive electrode active material layer 1a may also optionally include a binder and a conductive additive, etc. in addition to the positive electrode active material.

[0035] As the positive electrode active material, a known active material can be used. Two kinds of substances with different potentials (charge-discharge potentials) for occluding and releasing a predetermined ion in the known active materials can be selected. The substance with a high potential is used as the positive electrode active material, and the substance with a low potential is used as the negative electrode active material described later. For example, in the case of constructing a lithium ion battery, lithium cobaltate, lithium nickelate, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 , lithium manganate, spinel-type lithium compounds, and various lithium-containing composite oxides can be used as the positive electrode active material. In the case where the battery 100 is a all-solid-state battery, in order to suppress the reaction caused by the contact between the positive electrode active material and the solid electrolyte, a coating layer such as a lithium niobate layer, a lithium titanate layer, or a lithium phosphate layer can also be provided on the surface of the positive electrode active material. The positive electrode active material can be, for example, granular, and its size is not particularly limited.

[0036] In the case where the battery 100 is a all-solid-state battery, the solid electrolyte can be either an organic solid electrolyte (polymer solid electrolyte) or an inorganic solid electrolyte. In particular, the inorganic solid electrolyte has a higher ionic conductivity than the organic polymer electrolyte and is more excellent in heat resistance than the organic polymer electrolyte. As the inorganic solid electrolyte, for example, lithium lanthanum zirconate, LiPON, Li 1+X Al X Ge 2-X (PO 4 ) 3 , Li-SiO-based glass, Li-Al-S-O-based glass and other oxide solid electrolytes; Li 2 S-P 2 S 5 , Li 2 S-SiS 2 , LiI-Li 2 S-SiS 2 , LiI-Si 2 S-P 2 S 5 , Li 2 S-P 2 S 5 -LiI-LiBr, LiI-Li 2 S-P 2 S 5 , LiI-Li 2 S-P 2 O 5 , LiI-Li 3 PO 4 -P 2 S 5 , Li 2 S-P2 S 5 -GeS 2 sulfide solid electrolytes such as these. Among them, sulfide solid electrolytes, particularly those containing Li 2 S-P 2 S 5 have relatively high performance. The solid electrolyte can also be granular, for example, and its size is not particularly limited.

[0037] Examples of the binder include butadiene rubber (BR)-based binders, butene rubber (IIR)-based binders, styrene-butadiene rubber (SBR)-based binders, acrylate butadiene rubber (ABR)-based binders, polyvinylidene fluoride (PVdF)-based binders, polytetrafluoroethylene (PTFE)-based binders, and the like.

[0038] Examples of the conductive additive include carbon materials such as acetylene black and Ketjen black, and metal materials such as nickel, aluminum, and stainless steel. The conductive additive can also be granular or fibrous, for example, and its size is not particularly limited.

[0039] The content of each component in the positive electrode active material layer 1a may be the same as that of a known battery. The shape of the positive electrode active material layer 1a may also be the same as that of a known battery. From the viewpoint of being able to more easily construct the battery 100, the positive electrode active material layer 1a may also be in a sheet shape. The thickness of the positive electrode active material layer 1a is not particularly limited. For example, it may be 0.1 μm or more and 2 mm or less. The lower limit may also be 1 μm or more, and the upper limit may also be 1 mm or less.

[0040] 2.2 Negative electrode active material layer

[0041] The negative electrode active material layer 1b can include at least a negative electrode active material. In the case where the battery 100 is a all-solid-state battery, the negative electrode active material layer 1b may also optionally include a solid electrolyte, a binder, a conductive additive, etc. in addition to the negative electrode active material. Further, in the case where the battery 100 is an electrolyte-based battery, the negative electrode active material layer 1b may also include a binder and a conductive additive, etc. in addition to the negative electrode active material, and whether to include a binder and a conductive additive, etc. is optional.

[0042] As the negative electrode active material, a known active material can be used. For example, in the case of constructing a lithium-ion battery, as the negative electrode active material, silicon-based active materials such as Si, Si alloys, and silicon oxides; carbon-based active materials such as graphite and hard carbon; various oxide-based active materials such as lithium titanate; metallic lithium, lithium alloys, etc. can be used. The negative electrode active material can also be granular, for example, and its size is not particularly limited. The solid electrolyte, the binder, and the conductive additive can be appropriately selected from the substances exemplified as those used in the positive electrode active material layer 1a.

[0043] The content of each component in the negative electrode active material layer 1b may be the same as that of a known battery. The shape of the negative electrode active material layer 1b may also be the same as that of a known battery. From the viewpoint of being able to more easily construct the battery 100, the negative electrode active material layer 1b may also be in a sheet shape. The thickness of the negative electrode active material layer 1b is not particularly limited. For example, it may be 0.1 μm or more and 2 mm or less. The lower limit may also be 1 μm or more, and the upper limit may also be 1 mm or less. The thickness and the stacked area (electrode area) of the negative electrode active material layer 1b may be adjusted so that the capacity of the negative electrode is larger than the capacity of the positive electrode.

[0044] 2.3 Electrolyte layer

[0045] In addition to being able to be disposed as shown above in the positive electrode active material layer 1a and the negative electrode active material layer 1b, the electrolyte can also be disposed as an electrolyte layer 1c between the positive electrode active material layer 1a and the negative electrode active material layer 1b. As the electrolyte layer 1c of the battery, any usual electrolyte layer can be adopted. The electrolyte layer 1c includes at least an electrolyte. In the case where the battery 100 is a all-solid-state battery, the electrolyte layer 1c may also include a solid electrolyte and a binder, and whether to include a binder is optional. Regarding the solid electrolyte, as described above, especially an inorganic solid electrolyte, and among them, the sulfide solid electrolyte has higher performance. The binder can be appropriately selected and used the same binder as that used in the positive electrode active material layer 1a.

[0046] The content of each component in the electrolyte layer 1c may be the same as that of a known battery. The shape of the electrolyte layer 1c may also be the same as that of a known battery. From the viewpoint of being able to more easily construct the battery 100, the electrolyte layer 1c may also be in a sheet shape. The thickness of the electrolyte layer 1c may also be, for example, 0.1 μm or more and 2 mm or less. The lower limit may also be 1 μm or more, and the upper limit may also be 1 mm or less.

[0047] On the other hand, in the case where the battery 100 is an electrolyte-based battery, the electrolyte layer 1c can include an electrolyte solution and a separator. The electrolyte solution and the separator may be known substances. And, when comparing the case where the electrolyte layer 1c is a liquid-based electrolyte layer with the case where the electrolyte layer 1c is a solid electrolyte layer, it is generally considered that the case where the electrolyte layer 1c is a solid electrolyte layer, that is, the case where the battery 100 is an all-solid-state battery, is easier to construct the battery 100. In particular, compared with an electrolyte-based battery, an all-solid-state battery is easier to form a bipolar structure in the tandem body 10.

[0048] 2.4 Positive electrode current collector and negative electrode current collector

[0049] As Figure 1As shown, in the battery 100, at least a part of the electrode body 1 may also have a positive current collector 1d and a negative current collector 1e. The positive current collector 1d and the negative current collector 1e can adopt any usual current collectors as the current collectors of the battery. The positive current collector 1d and the negative current collector 1e may also be a metal foil or a metal mesh. In particular, the operability of the metal foil is excellent. The positive current collector 1d and the negative current collector 1e may also be composed of multiple metal foils respectively.

[0050] Examples of the metal constituting the positive current collector 1d and the negative current collector 1e include Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, stainless steel, etc. In particular, from the viewpoint of maintaining oxidation resistance, the positive current collector 1d may include Al, and from the viewpoint of maintaining reduction resistance, the negative current collector 1e may also include Cu.

[0051] For the purpose of adjusting resistance, etc., the positive current collector 1d and the negative current collector 1e may also have an arbitrary coating on their surfaces. In addition, when the positive current collector 1d and the negative current collector 1e are composed of multiple metal foils, an arbitrary layer may also be provided between the multiple metal foils. The thickness of the positive current collector 1d and the negative current collector 1e is not particularly limited. For example, it may be 0.1 μm or more or 1 μm or more, and may also be 1 mm or less or 100 μm or less.

[0052] 3. Intermediate current collector

[0053] As Figure 1 and Figure 2 shown, in one series body 10, multiple electrode bodies 1 are electrically connected in series with each other via an intermediate current collector 3. That is, the intermediate current collector 3 can be arranged between the positive electrode active material layer 1a of one electrode body 1 and the negative electrode active material layer 1b of another electrode body 1. From the viewpoints of being able to easily maintain a high voltage, improving the energy density, etc., the series body 10 may also have a bipolar structure, and in this case, the intermediate current collector 3 may also be a bipolar current collector. That is, as Figure 1 shown, a positive electrode active material layer 1a may be laminated on one surface of the intermediate current collector 3, and a negative electrode active material layer 1b may be laminated on the other surface.

[0054] The intermediate current collector 3 can also be made of metal. Alternatively, as described later, it may contain a resin and a conductive material. The intermediate current collector 3 can also be composed of multiple layers (or foils). When the intermediate current collector 3 is made of metal, examples of the metal constituting the intermediate current collector 3 include Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, stainless steel, etc. For the purpose of adjusting resistance, etc., the intermediate current collector 3 may have a certain coating on its surface. The thickness of the intermediate current collector 3 is not particularly limited. For example, it may be 0.1 μm or more or 1 μm or more, and may also be 1 mm or less or 100 μm or less.

[0055] When the intermediate current collector 3 includes a resin and a conductive material, it is easy to make the battery 100 lighter, and in addition, it is easy to improve the safety of the battery 100. The resin can be, for example, an ethylene resin. In addition, the conductive material can be, for example, a carbon material or a metal material. As the metal material, the same metal materials as those described above can be used. The shape of the conductive material is not particularly limited. For example, it can be granular. The intermediate current collector 3 can be obtained, for example, by forming a mixture of the above resin and the conductive material into a thin sheet. The ratio of the resin and the conductive material in the intermediate current collector 3 is not particularly limited, as long as the shape stability and mechanical properties as a current collector are maintained and the conductivity sufficient to electrically connect the electrode bodies 1 in series with each other is maintained.

[0056] 4. Electrical connection

[0057] As Figures 1 to 3 shown, the battery 100 has at least three types of electrical connections: parallel connection between the series bodies 10, series connection between the electrode bodies 1 in the series body 10, and direct connection between the intermediate current collector 3 of the first series body 10 and the intermediate current collector 3 of the second series body 10.

[0058] 4.1 Parallel connection between series bodies

[0059] As Figures 1 to 3 shown, in the battery 100, multiple series bodies 10 are electrically connected in parallel to each other. The electrical connection between the series bodies 10 can be carried out, for example, by making the positive electrode collector tab 20 protrude from the positive electrode current collector 1d, making the negative electrode collector tab 30 protrude from the negative electrode current collector 1e, and bundling and integrating the positive electrode collector tabs 20 with each other and bundling and integrating the negative electrode collector tabs 30 with each other, or by fixing or integrating terminals, etc. on the positive electrode current collector 1d and the negative electrode current collector 1e and electrically connecting the terminals to each other, or by other methods.

[0060] In addition, as described later, although a high voltage can be maintained by connecting the electrode bodies 1 in series with each other to form a series body 10, when only the electrode bodies 1 are connected in series with each other, it is difficult to maintain a sufficient capacity as the entire battery. In contrast, in the battery 100, by electrically connecting a plurality of series bodies 10 in parallel, the capacity of the entire battery 100 is increased. The number of series bodies 10 connected in parallel can be appropriately determined according to the capacity of the battery as the purpose. In the battery 100, it is sufficient that there are a plurality of series bodies 10, which can be two or more, three or more, four or more, or five or more.

[0061] 4.2 Series connection between electrode bodies

[0062] As Figures 1 to 3 shown, in one series body 10, a plurality of electrode bodies 1 are electrically connected in series with each other via an intermediate current collector 3. In the battery 100, the electrode bodies 1 can be electrically connected in series with each other by a known method. For example, by disposing the positive electrode of one electrode body 1 on one surface of the intermediate current collector 3 and disposing the negative electrode of another electrode body 1 on another surface, the one electrode body 1 and the another electrode body 1 can be electrically connected in series. As described above, the series body 10 may have a bipolar structure, that is, the intermediate current collector 3 may also be a bipolar current collector.

[0063] The number of electrode bodies 1 included in one series body 10 is not particularly limited. However, when the number is small, it is easy to monitor and estimate the voltage of each electrode body 1, and it is also easy to improve safety. In this regard, in one series body 10, the number of a plurality of electrode bodies 1 electrically connected in series with each other via the intermediate current collector 3 can be two or three. And when one electrode body has a voltage of about 3.5V to 4.5V, by connecting three such electrode bodies in series, a series body and a battery having a voltage of about 12V can be obtained. The battery having a voltage of about 12V has good usability and high demand.

[0064] 4.3 Direct connection between intermediate current collectors

[0065] As Figures 1 to 3 shown, in the battery 100, the intermediate current collector 3 of the first series body 10 and the intermediate current collector 3 of the second series body 10 are directly electrically connected to each other. "Direct electrical connection" means that there is a direct conductive path between the intermediate current collector 3 of the first series body 10 and the intermediate current collector 3 of the second series body 10 without passing through the electrode body 1. That is, in addition to the parallel connection between the series bodies 10 and the series connection between the electrode bodies 1, the battery 100 also has a direct conductive path between the intermediate current collectors 3.

[0066] The direct connection between the intermediate current collector 3 of the first tandem body 10 and the intermediate current collector 3 of the second tandem body 10 can be achieved, for example, as follows. Figures 1 to 3 As shown, it can be carried out by protruding the intermediate current collector tabs 40 from the intermediate current collectors 3 and bundling and integrating these intermediate current collector tabs 40 with each other, or by fixing or integrating terminals or the like to the intermediate current collectors 3 and electrically connecting these terminals with each other, or by other methods.

[0067] In the battery 100, when one tandem body 10 contains a plurality of intermediate current collectors 3 (that is, when the number of electrode bodies connected in series is three or more), at least one of the plurality of intermediate current collectors 3 included in the first tandem body 10 and at least one of the plurality of intermediate current collectors 3 included in the second tandem body 10 may be directly electrically connected. In addition, the plurality of intermediate current collectors 3 of the second tandem body 10 may also be directly electrically connected to one intermediate current collector 3 of the first tandem body 10.

[0068] In this way, by directly electrically connecting the intermediate current collectors 3 with each other in addition to the parallel connection between the tandem bodies 10 and the series connection between the electrode bodies 1, even if an abnormal capacity reduction occurs in a specific electrode body 1, the current is dispersed and the voltage is balanced between the tandem body 10 containing this electrode body 1 and other tandem bodies 10, and it is easy to suppress the voltage deviation in the tandem body 10 containing the electrode body 1 with the capacity reduction.

[0069] 5. Laminated structure

[0070] The battery 100 may also have a predetermined laminated structure. For example, as Figure 1 and Figure 3 shown, in the battery 100, a plurality of tandem bodies 10 may be laminated with each other, and in each of the plurality of tandem bodies 10, a plurality of electrode bodies 1 may be laminated with each other, and the lamination directions of the plurality of tandem bodies 10 and the lamination directions of the plurality of electrode bodies 1 may also be the same. More specifically, a positive electrode active material layer 1a of one electrode body 1 may be laminated on one surface of the intermediate current collector 3, and a negative electrode active material layer 1b of another electrode body 1 may be laminated on the other surface, or a positive electrode active material layer 1a of one electrode body 1 may be laminated on one surface of the positive current collector 1d, and a positive electrode active material layer 1a of another electrode body 1 may be laminated on the other surface, or a negative electrode active material layer 1b of one electrode body 1 may be laminated on one surface of the negative current collector 1e, and a negative electrode active material layer 1b of another electrode body 1 may be laminated on the other surface. Thus, one electrode body 1 and another electrode body 1 can be electrically connected in series, and in addition, the first tandem body 10 and the second tandem body 10 can be electrically connected in parallel. In other words, a laminate of a plurality of electrode bodies 1 and the intermediate current collectors 3 is obtained, and this laminate has both a series connection structure (which may be a bipolar structure) and a parallel connection structure. As Figure 1As shown, on the side surface of the thus obtained laminate, the battery 100 can also be formed by electrically connecting the positive current collectors 1d to each other, the negative current collectors 1e to each other, and the intermediate current collectors 3 to each other via the above-mentioned tabs or the like.

[0071] 6. Other components

[0072] The battery 100 may also have other components in addition to the above. The components described below are an example of other components that the battery 100 can have.

[0073] 6.1 Outer package

[0074] As Figure 4 shown, in the battery 100, a plurality of series bodies 10 may be housed inside one outer package 50. More specifically, portions other than the tabs 20, 30 (or terminals, etc.) for taking out electric power from the battery 100 to the outside may be housed inside one outer package 50. In addition, in the battery 100, at least a part of the intermediate current collector 3 and the tab 40 may be outside the outer package 50, or the entire tab 40 and the intermediate current collector 3 may be housed inside the outer package 50. In particular, when the entire tab 40 and the intermediate current collector 3 are housed inside the outer package 50 (in other words, when the intermediate current collector 3 is not led out to the outside of the outer package 50), it is easy to avoid interference between the intermediate current collector 3 and the positive current collector tab 20 and the negative current collector tab 30, and in addition, the sealing of the outer package 50 is also easy.

[0075] As the outer package of the battery, any known outer package can be adopted for the outer package 50. For example, a laminated film can also be used as the outer package 50. In addition, a plurality of batteries 100 may be electrically connected and arbitrarily stacked to form a battery pack. In this case, the battery pack may also be housed inside a known battery case.

[0076] 6.2 Encapsulating resin

[0077] In the battery 100, the series body 10 may be sealed with resin. For example, as Figure 1 shown, on the basis of laminating a plurality of series bodies 10 to form a laminate, at least the side surface (the surface along the lamination direction) of the laminate may be sealed with resin. Thereby, it is easy to suppress the intrusion of moisture into the inside of the electrode body 1, etc. As the encapsulating resin, known thermosetting resins and thermoplastic resins can be adopted. In the battery 100, a plurality of series bodies 10 may also be housed inside the above-mentioned outer package 50 in a state of being sealed with resin.

[0078] 6.3 Voltage monitoring device

[0079] The battery 100 may also have a device for monitoring the voltage of each of the plurality of electrode bodies 1. Regarding the device for monitoring the voltage of the electrode body 1, any known device can be adopted.

[0080] 6.4 Constraint member

[0081] The battery 100 may also have a constraint member for constraining the electrode body 1. For example, as described above, in the case where a laminate is formed by laminating a plurality of series bodies 10, a constraint pressure may be applied to the laminate in the lamination direction by using the constraint member. In particular, in the case where the battery 100 is an all-solid-state battery, by applying a constraint pressure by the constraint member, it is easy to reduce the internal resistance of the electrode body 1.

[0082] Hereinafter, embodiments will be shown and the effects of the battery of the present disclosure will be described in more detail. However, the battery of the present disclosure is not limited to the following embodiments. In the following embodiments, an all-solid-state battery using a solid electrolyte as an electrolyte is exemplified. However, the application target of the technology of the present disclosure is not limited to all-solid-state batteries. It is generally considered that the same effects are also exhibited when the technology of the present disclosure is applied to a liquid-based battery. However, an all-solid-state battery is more easily configured into a bipolar structure than a liquid-based battery.

[0083] 1. Embodiment

[0084] 1.1 Preparation of positive electrode mixture

[0085] A positive electrode active material (LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 ), a solid electrolyte (LiI-LiBr-Li 2 S-P 2 S 5 ), a conductive additive (VGCF), and an adhesive (ABR) are mixed at a predetermined ratio to obtain a positive electrode mixture.

[0086] 1.2 Preparation of negative electrode mixture

[0087] A negative electrode active material (graphite), a solid electrolyte (LiI-LiBr-Li 2 S-P 2 S 5 ), and an adhesive (ABR) are mixed at a predetermined ratio to obtain a negative electrode mixture.

[0088] 1.3 Preparation of electrolyte mixture

[0089] A solid electrolyte (LiI-LiBr-Li 2 S-P 2 S 5) and an adhesive (ABR) to obtain an electrolyte mixture.

[0090] 1.4 Fabrication of the battery

[0091] Using the positive electrode active material layer obtained from the above positive electrode mixture, the negative electrode active material layer obtained from the negative electrode mixture, the electrolyte layer obtained from the electrolyte mixture, the positive electrode current collector (aluminum foil), the negative electrode current collector (copper foil), and the intermediate current collector (a resin foil formed by shaping a mixture of ethylene resin and conductive particles into a thin sheet), a laminate having the Figure 1 shown structure is fabricated. Here, in one series body, the number of electrode bodies electrically connected in series via the intermediate current collector is 2. In addition, three series bodies are electrically connected in parallel. Further, as Figure 1 and Figure 3 shown, on the side surface of the laminate, while making the electrode tabs protrude from each current collector, the positive electrode current collectors, the negative electrode current collectors, and the intermediate current collectors are directly electrically connected to each other using these electrode tabs. After connecting these current collectors, the laminate is sealed in a laminated film as an exterior body to obtain a battery for evaluation. Here, as Figure 4 shown, a part of the positive electrode collector tab and the negative electrode collector tab is led out to the outside of the laminated film via a sealing material.

[0092] 2. Comparative example

[0093] A battery is obtained in the same manner as in the example except that the intermediate current collectors are not directly electrically connected to each other.

[0094] 3. Evaluation results

[0095] In Figure 5 is shown an example of the voltage deviation in the case where the structure of the battery of the example and the capacity of a part of the electrode body are abnormally reduced. As Figure 5 shown, in the battery of the example, by directly electrically connecting the intermediate current collectors to each other, even if an abnormal capacity reduction occurs in a specific electrode body, the voltage is balanced between the series body containing the electrode body and other series bodies, and it is easy to suppress the voltage deviation in the series body containing the electrode body.

[0096] In Figure 6 is shown an example of the voltage deviation in the case where the structure of the battery of the comparative example and the capacity of a part of the electrode body are abnormally reduced. As Figure 6 shown, in the battery of the comparative example, if an abnormal capacity reduction occurs in a specific electrode body, the voltage deviation becomes significant in the series body containing the electrode body, and there is a possibility of rapid deterioration of the battery.

[0097] As described above, it can be said that in a battery in which a plurality of electrode bodies have a plurality of series-connected bodies connected in series with each other, and the plurality of series-connected bodies are connected in parallel with each other, it is effective to electrically connect the intermediate current collectors to each other in order to suppress the deviation of the voltages of the plurality of electrode bodies. Specifically, it is preferable that the battery has the following structure.

[0098] The battery has a plurality of series-connected bodies including a first series-connected body and a second series-connected body,

[0099] Each of the plurality of series-connected bodies has a plurality of electrode bodies,

[0100] Each of the plurality of series-connected bodies has at least one intermediate current collector,

[0101] The plurality of series-connected bodies are electrically connected in parallel with each other,

[0102] In each of the plurality of series-connected bodies, the plurality of electrode bodies are electrically connected in series with each other via the intermediate current collector,

[0103] The intermediate current collector of the first series-connected body and the intermediate current collector of the second series-connected body are directly electrically connected to each other.

Claims

1. A battery, characterized in that, it has a plurality of series bodies including a first series body and a second series body, each of the plurality of series bodies has a plurality of electrode bodies, each of the plurality of series bodies has at least one intermediate current collector, the plurality of series bodies are stacked on one another and electrically connected in parallel, in each of the plurality of series bodies, the plurality of electrode bodies are electrically connected in series with each other via the intermediate current collector, the intermediate current collector of the first series body and the intermediate current collector of the second series body are directly electrically connected to each other through a direct conductive path that does not pass through the electrode body.

2. The battery according to claim 1, characterized in that, at least one of the plurality of series bodies has a bipolar structure.

3. The battery according to claim 1 or 2, characterized in that, the intermediate current collector includes a resin and a conductive material.

4. The battery according to claim 1 or 2, characterized in that, in the first series body, the number of the plurality of electrode bodies electrically connected in series with each other via the intermediate current collector is 2 or 3.

5. The battery according to claim 1 or 2, characterized in that, the plurality of series bodies are housed inside one outer package.

6. The battery according to claim 1 or 2, characterized in that, in each of the plurality of series bodies, the plurality of electrode bodies are stacked on one another, the stacking direction of the plurality of series bodies is the same as the stacking direction of the plurality of electrode bodies.

7. The battery according to claim 1 or 2, characterized in that, this battery is an all-solid-state battery.

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