JP2014086388A - Battery pack and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack and a manufacturing method thereof, capable of easily enlarging a capacity, improving output density, and manufacturing with high productivity.SOLUTION: A battery pack includes two or more battery modules each connected in series, and each of battery modules consists of a plurality of secondary battery cells having a first group to nth group (N is two or larger integral number). A positive-electrode current collecting foil and a negative-electrode current collecting foil of each secondary battery cell have extending parts extending to the outer side from two end portions at the opposite side, respectively. In an arbitrary adjacent two battery modules, the extending parts of the positive-electrode current collecting foil and negative-electrode current collecting foil of the plurality of secondary battery cells having the first group to nth group in one of the battery modules are connected to extending parts of a plurality of current collecting foils with a different polarity of the plurality of secondary battery cells having the first group to nth group in the other battery module existing at a position overlapping to the former extending parts.

Description

  The present invention relates to an assembled battery, and more particularly, to an assembled battery in which the output density is improved by reducing the volume of a junction between electrodes of two or more battery modules arranged side by side, and a method for manufacturing the assembled battery.

  An all-solid secondary battery in which the electrolyte is a solid electrolyte does not use a flammable organic solvent in the battery. Therefore, it is considered that the safety device can be simplified and the manufacturing cost and productivity are excellent. Furthermore, in recent years, as the demand for hybrid vehicles and the like increases, it is required to achieve higher energy density and output density and further miniaturization of all solid state secondary batteries. For example, Patent Document 1 describes that by reducing the thickness of the current collector foil, the power storage element can be reduced in size without reducing the current capacity. In order to obtain a higher output density, it is necessary to make the positive electrode and the negative electrode current collector foil thinner (see, for example, Patent Document 1). It has high energy density and high output density by juxtaposing and connecting a plurality of battery modules formed by stacking a plurality of secondary battery cells having a positive electrode current collector foil and a negative electrode current collector foil via an insulator. An assembled battery can be obtained.

  However, as shown in FIGS. 1 (a) and 1 (b), a plurality of positive current collectors extending from the ends of a plurality of secondary battery cells (unit cells) (110, 120) in the battery module. A plurality of negative electrode current collector foils (or positive electrode current collectors) extending from the extending portions (111, 112, 113) of the foil (or negative electrode current collector foils) and end portions of the plurality of secondary battery cells in the adjacent battery modules In the case where the extending portions (121, 122, 123) of the electric foil) are joined in an alternately superposed state, the lengths of the extending portions of the positive current collecting foil and the negative current collecting foil are adjacent to each other. Because the current collector foil extending portion that is closer to the junction (boundary portion) with the battery module needs to be shorter (that is, the length of the extending portion 111 <the length of the extending portion 112 <the extending portion) 113, and the length of the extended portion 121 <the length of the extended portion 122 <the length of the extended portion 123), the positive electrode It is difficult to bond superimposed on the alternating foil and the anode current collector foil has a problem of poor productivity. In particular, as the number of secondary battery cells is increased in order to obtain a higher energy density, it is difficult to alternately overlap and join. It is conceivable that the lengths of the extending portions of the positive electrode current collector foil and the negative electrode current collector foil are all the same, and the positive electrode current collector foil and the negative electrode current collector foil are alternately overlapped and joined. When the extension portions are alternately stacked, the current collector foil extension portion on the joint portion side between adjacent battery modules is pressed from the extension portion on the outer side to cause bending or wrinkles. There was a problem in that the current collector foil could cause damage. Furthermore, even when the lengths of the extending portions of the plurality of positive electrode current collector foils (or negative electrode current collector foils) extending from the end portions of the plurality of secondary battery cells are different or the same, the plurality of adjacent battery modules As the number of current collector foil extending portions alternately superposed with the extended portions of the plurality of negative electrode current collector foils (or positive current collector foils) extending from the end of the secondary battery cell of FIG. ), The height (h) of the junction between the positive electrode current collector foil and the negative electrode current collector foil from the end of the secondary battery cell is increased, and the bulkiness of the junction is increased accordingly. However, as a result of an increase in the volume of the joint between the current collector foil electrodes, there is a problem that the output density is lowered.

JP 2007-335150 A

  In view of the above-described problems of the conventional technology, an object of the present invention is to provide an assembled battery that can easily realize a large capacity, has an improved output density, and can be manufactured with high productivity, and a manufacturing method thereof. And

According to the present invention, in one embodiment, an assembled battery including two or more battery modules connected in series,
Each battery module includes a plurality of secondary battery cells of the first group to the Nth group (N is an integer of 2 or more), and the plurality of secondary battery cells of the first group to the Nth group are respectively in the thickness direction. A positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil, which are laminated in order, each of the positive electrode current collector foil and the negative electrode current collector foil of each secondary battery cell, Each having an extending portion extending outward from the end portion;
In each group of the plurality of secondary battery cells of each of the first group to the Nth group of each battery module, the plurality of secondary batteries are stacked via an electrical insulating layer to form a stacked body, A stack of a plurality of secondary battery cells of Group 1 to Group N is stacked via an electrical insulating layer,
In each battery module, the positions of the extending portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the N group are different from each other between the first group to the N group,
In any two adjacent battery modules, the extension portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the Nth group in one battery module are respectively extended. A plurality of secondary battery cells of the first group to the N-th group in the other battery module existing at a position overlapping with the portion are connected to the extending portions of the current collector foils having different polarities, An assembled battery is provided.

  In the assembled battery of the present invention, a positive current collector foil and a negative electrode extending outward from two opposite ends of a plurality of secondary battery cells (unit cells) constituting each battery module of the current collector foil The extending portions of the current collector foil do not extend from the same position of each end toward the outside of the cell so that they all overlap when they are joined in series between the battery modules, but a plurality of components constituting each battery module The secondary battery cells are divided into N groups (N is an integer of 2 or more), and a plurality of secondary batteries of the first group to the Nth group are provided in each battery module corresponding to the number of divisions (N). The positions of the extending portions of the positive electrode current collector foil and the negative electrode current collector foil of the cell are different from each other between the first group to the Nth group (that is, the first group to the Nth group when joined in series between the battery modules). Different from each other at the two opposite ends. By providing an extending portion extending outward from each of the N locations, the volume of the joint between the electrodes of the battery module can be reduced by connecting current collecting foils having different polarities in any two adjacent battery modules, Thereby, the output density of the assembled battery can be increased.

According to still another embodiment of the present invention, there is provided a method of manufacturing a battery pack including two or more battery modules connected in series,
A method of manufacturing an assembled battery including two or more battery modules connected in series,
(A) Each secondary battery cell includes a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil that are sequentially stacked in the thickness direction. , A plurality of secondary battery cells in the first group to the Nth group (N is an integer of 2 or more) each having an extending portion extending outward from two opposite ends of each secondary battery cell. Here, the positions of the extending portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells in the first group to the N group are different from each other in the first group to the N group). Prepare one set for each module,
(B) In each group of the plurality of secondary battery cells of the first group to the Nth group, a plurality of secondary battery cells are stacked via an electrical insulating layer to form a stacked body, and the first obtained A battery module is formed by laminating a stack of secondary battery cells of group N to group N via an electrical insulating layer,
(C) Prepare two or more battery modules by repeating the steps (A) and (B) at least once,
(D) In any adjacent battery module, the extension portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the Nth group in one battery module are respectively Two or more by connecting with the extension part of several current collector foil from which the polarity of the several secondary battery cell of the 1st group-N group in the other battery module which exists in the position which overlaps with an existing part differs Connecting battery modules in series,
A method for manufacturing an assembled battery is provided.

  According to the present invention, the productivity is improved by dispersing the positions of the joints when connecting any two adjacent battery modules in series, and the battery is obtained by dispersing the positions of the joints. Since the volume of the junction between the electrodes of the module can be reduced, the power density can be increased. Furthermore, the number of secondary battery cells in the battery module can be increased by dispersing the positions of the joints. Therefore, according to the present invention, the capacity can be easily increased, and an assembled battery having a high output density can be obtained with high productivity.

1 (a) to 1 (c) show, according to the prior art, alternately extending portions of a plurality of current collector foils having different polarities extending from end portions of a plurality of secondary battery cells in adjacent battery modules. It is the schematic which shows the method of superimposing and joining. FIG. 2 is an exploded perspective view schematically showing a secondary battery cell incorporated in each battery module in the assembled battery according to one embodiment of the present invention. FIG. 3 is a schematic perspective view schematically showing an example of a secondary battery cell according to an embodiment of the present invention. 4 (a) to 4 (b) are front views showing aspects of a positive electrode current collector foil and a negative electrode current collector foil that can be used for manufacturing a secondary battery cell according to an embodiment of the present invention. FIG. 5 is a schematic perspective view schematically showing one aspect of a method for connecting battery modules. FIG. 6 is a schematic perspective view schematically showing another aspect of the method for connecting the battery modules.

Next, the present invention will be described with reference to the drawings.
FIG. 2 is an exploded perspective view schematically showing a secondary battery cell incorporated in each battery module in the assembled battery according to one embodiment of the present invention. As shown in FIG. 2, the secondary battery cell 20 includes a positive electrode current collector foil 21, a positive electrode layer 22, a solid electrolyte layer 23, a negative electrode layer 24, and a negative electrode current collector foil 25 stacked in the thickness direction. In the secondary battery cell 20, a positive electrode layer 22 is provided on the positive electrode current collector foil 21, and a negative electrode layer 24 is provided on the negative electrode current collector foil 25. The positive electrode current collector foil 21 and the negative electrode current collector foil 25 have extending portions 21a and 25a, respectively. In the secondary battery cell 20 shown in FIG. 2, the extension part 21 a of the positive electrode current collector foil and the extension part 25 a of the negative electrode current collector foil are provided at diagonal positions of the secondary battery cell 20. . If the extending portions 21a and 25a extend outward from two different locations of the two opposite ends of the secondary battery cell, respectively, the positions of the extending portions 21a and 25a are mutually It is not limited to the diagonal position. In the secondary battery cell 20 shown in FIG. 2, the positive electrode current collector foil 21, the positive electrode layer 22, the solid electrolyte layer 23, the negative electrode layer 24, and the negative electrode current collector foil 25 are viewed from the stacking direction. And the area | region except the extension part of each collector foil of the negative electrode collector foil 25 is a rectangle.

  FIG. 3 is a perspective view schematically showing the secondary battery cell 20 formed by laminating the positive electrode current collector foil 21, the positive electrode layer 22, the solid electrolyte layer 23, the negative electrode layer 24, and the negative electrode current collector foil 25. .

  FIG. 4A is a front view schematically showing the positive electrode current collector foil 21 and the negative electrode current collector foil 25 in the secondary battery cell of the embodiment shown in the perspective view in FIGS. FIG. 4B is a front view schematically showing another embodiment of the positive electrode current collector foil and the negative electrode current collector foil that can be used together with the positive electrode current collector foil 21 and the negative electrode current collector foil 25 shown in FIG. FIG. The positive electrode current collector foil 31 has an extension part 31a, and the negative electrode current collector foil 32 has an extension part 32a. The positive electrode current collector foil 21 and the positive electrode current collector foil 31 are different in the position of the extending portion. In the positive electrode current collector foil 21, the extending portion 21 a is provided at one end of one side (left end portion in FIG. 4B), whereas in the positive electrode current collector foil 31, the extended portion 31 a is at the center of one side. Provided in the department. Similarly, in the negative electrode current collector foil 25, the extending portion 25a is provided at one end of one side (the right end portion in FIG. 4B), whereas in the positive electrode current collector foil 32, the extending portion 32a is provided on one side. It is provided in the central part.

  Four types of secondary battery cells can be manufactured by using two types of positive electrode current collector foils having different extension portions and two types of negative electrode current collector foils having different extension portions. it can. For example, in addition to the combination of the positive electrode current collector foil 21 and the negative electrode current collector foil 25 illustrated in FIGS. 2 and 3, the combination of the positive electrode current collector foil 21 and the negative electrode current collector foil 32, the positive electrode current collector foil 31 and the negative electrode current collector Four types of secondary battery cells can be manufactured using the combination of the electric foil 25 and the combination of the positive electrode current collector foil 31 and the negative electrode current collector foil 32. As long as the extension part of the positive electrode current collector foil and the extension part of the negative electrode current collector foil respectively extend outward from different locations of the two opposite ends of the secondary battery cell, respectively, any A plurality of current collector foils can be used in combination. A plurality of secondary battery cells in which the positions of the extension part 21a of the positive electrode current collector foil and the extension part 25a of the negative electrode current collector foil are the same are defined as a plurality of secondary battery cells of the same group. The secondary battery cell is laminated with another group of secondary battery cells via an electrical insulating layer to form a laminate. Each battery module is provided with a stack of a plurality of secondary battery cells of the first group to the Nth group (N is an integer of 2 or more). A stack of a plurality of secondary battery cells of the first group to the Nth group (a stack of a plurality of secondary battery cells of the first group, a stack of a plurality of secondary battery cells of the second group, ... A stack of a plurality of secondary battery cells of the Nth group is stacked with an electric insulating layer therebetween. Although the laminated body of the secondary battery cells of the first group to the Nth group is not shown, the battery module can be formed by pressing after further alignment with a tape or the like.

  After forming a plurality of battery modules by the above method, the battery modules are connected in series. With reference to FIGS. 5 and 6, the present invention will be described with reference to an example in which two battery modules are connected in series. 5 and 6, in order to facilitate understanding of a method of connecting battery modules in series, only a stack of a plurality of secondary battery cells in two battery modules is shown, and a plurality of secondary battery cells are shown. The electrical insulation layer disposed between them and other components of the battery module are omitted. FIG. 5 is a schematic perspective view schematically showing one aspect of a method for connecting battery modules. In the embodiment shown in FIG. 5, each battery module is composed of two secondary battery cell groups using a pair of current collector foils as shown in FIG. That is, in the embodiment shown in FIG. 5, the battery module 310 includes a first group of secondary battery cells 311, 312, 313 and a second group of secondary battery cells 314, 315, 315, and the battery module 320 includes the first group. Secondary battery cells 321, 322, and 323 and a second group of secondary battery cells 324, 325, and 326. The secondary battery cells 321, 322, and 323 of the first group of the battery module 320 and the secondary battery cells 324, 325, and 326 of the second group are the secondary battery cells 311, 312, and 313 of the first group of the battery module 310. And the second group of secondary battery cells 314, 315, and 315 are rotated by 180 ° with their stacking direction as the central axis.

  The extending portions of the positive electrode current collector foils of the plurality of secondary battery cells in the same group in each battery module are in positions overlapping each other in the stacking direction of the secondary battery cells, and the plurality of secondary battery cells in the same group The extending part of the negative electrode current collector foil is at a position where they overlap each other in the stacking direction of the secondary battery cells. That is, in FIG. 5, the extending portions 311a, 312a, and 313a of the positive electrode current collector foils of the first group of secondary battery cells 311, 312, and 313 in the battery module 310 are mutually connected in the stacking direction of the secondary battery cells. The extending portions 311b, 312b, and 313b of the negative electrode current collector foil are in positions that overlap each other in the stacking direction of the secondary battery cells. Similar to the first group of secondary battery cells 311, 312, 313, the extension portions 314 a, 315 a of the positive electrode current collector foils of the second group of secondary battery cells 314, 315, 316 in the battery module 310, 316a is in a position where they overlap each other in the stacking direction of the secondary battery cells, and the extending portions 314b, 315b, 316b of the negative electrode current collector foil are in positions where they overlap each other in the stacking direction of the secondary battery cells. Similarly to the battery module 310, the extending portions 321a, 322a, and 323a of the positive electrode current collector foils of the first group of secondary battery cells 321, 322, and 323 in the battery module 320 are arranged in the stacking direction of the secondary battery cells. The extending portions 321b, 322b, and 323b of the negative electrode current collector foil are in positions that overlap each other in the stacking direction of the secondary battery cells. Similarly to the first group of secondary battery cells 321, 322, and 323, the extension portions 324a, 325a, and 326a of the positive electrode current collector foils of the second group of secondary battery cells 324, 325, and 326 are secondary batteries. The extending portions 324b, 325b, and 326b of the negative electrode current collector foil are in positions that overlap each other in the stacking direction of the secondary battery cells. Furthermore, the extending portions 311 a, 312 a, and 313 a of the positive electrode current collector foils of the first group of secondary battery cells 311, 312, and 313 in the battery module 310 are the first group of secondary batteries in the battery module 320. Respective positive electrodes of the second group of secondary battery cells 314, 315, and 316 in the battery module 310, at positions overlapping with the extending portions 321 b, 322 b, and 323 b of the negative electrode current collector foils of the cells 321, 322, and 323, respectively. The extension portions 314 a, 315 a, and 316 a of the current collector foil overlap the extension portions 324 b, 325 b, and 326 b of the negative electrode current collector foil of the second group of secondary battery cells 324, 325, and 326 in the battery module 320. In position. In FIG. 5, a pair of extended portions of the plurality of positive electrode current collector foils and extended portions of the plurality of negative electrode current collector foils to be joined is indicated by double-ended arrow lines.

  FIG. 6 is a schematic perspective view schematically showing another aspect of the method for connecting the battery modules. Similar to the embodiment shown in FIG. 5, in FIG. 6, only a stack of a plurality of secondary battery cells in two battery modules is shown in order to facilitate understanding of a method of connecting battery modules in series. In addition, the electrical insulation layer disposed between the plurality of secondary battery cells and other components of the battery module are omitted. In FIG. 6, the extending portions 311 a, 312 a, and 313 a of the positive electrode current collector foils of the first group of secondary battery cells 311, 312, and 313 in the battery module 310 overlap each other in the stacking direction of the secondary battery cells. The extending portions 311b, 312b, and 313b of the negative electrode current collector foil are in positions that overlap each other in the stacking direction of the secondary battery cells. Similar to the first group of secondary battery cells 311, 312, 313, the extension portions 314 a, 315 a of the positive electrode current collector foils of the second group of secondary battery cells 314, 315, 316 in the battery module 310, 316a is in a position where they overlap each other in the stacking direction of the secondary battery cells, and the extending portions 314b, 315b, 316b of the negative electrode current collector foil are in positions where they overlap each other in the stacking direction of the secondary battery cells. Similarly to the battery module 310, the extending portions 331a, 332a, 333a of the positive electrode current collector foils of the first group of secondary battery cells 331, 332, 333 in the battery module 330 are arranged in the stacking direction of the secondary battery cells. The extending portions 331b, 332b, and 333b of the negative electrode current collector foil are in positions that overlap each other in the stacking direction of the secondary battery cells. Similar to the first group of secondary battery cells 331, 332, and 333, the extending portion (not shown) of the positive electrode current collector foil of each of the second group of secondary battery cells 334, 335, and 336 is a secondary battery. The extending portions 334b, 335b, and 336b of the negative electrode current collector foil are in positions that overlap each other in the stacking direction of the secondary battery cells. Furthermore, the extending portions 311 a, 312 a, and 313 a of the positive electrode current collector foils of the first group of secondary battery cells 311, 312, and 313 in the battery module 310 are the second group of secondary batteries in the battery module 330. Respective positive electrodes of the second group of secondary battery cells 314, 315, and 316 in the battery module 310 at positions overlapping with the extending portions 334 b, 335 b, and 336 b of the negative electrode current collector foils of the cells 334, 335, and 336, respectively. The current collector foil extending portions 314 a, 315 a, and 316 a overlap the negative electrode current collector foil extending portions 331 b, 332 b, and 333 b of the first group of secondary battery cells 331, 332, and 333 in the battery module 330, respectively. In position. In FIG. 6, a pair of extended portions of the plurality of positive electrode current collector foils and extended portions of the plurality of negative electrode current collector foils to be joined is indicated by double-ended arrow lines.

  The extension part of the positive electrode current collector foil and the extension part of the negative electrode current collector foil extending from a plurality of secondary battery cells in one battery module respectively extend from a plurality of secondary battery cells in another battery module When joining with the extended part of the negative electrode current collector foil and the extended part of the positive electrode current collector foil, as shown in FIG. 1C, the extended part of the plurality of positive electrode current collector foils and the plurality of negative electrode current collector foils Or a plurality of positive electrode current collector foils and a plurality of negative electrode current collector foil bundles may be overlapped and joined together. Good. It is said that the flow of current becomes smooth by joining the first layer, the first layer, the second layer, the second layer, ..., the nth layer and the nth layer of both the secondary battery cells to be joined. For the reason, it is preferable that the extending portions of the plurality of positive electrode current collector foils and the extending portions of the plurality of negative electrode current collector foils are alternately overlapped and joined. In order to enhance the adhesiveness of the joint portion when the extension portions of the plurality of positive electrode current collector foils and the extension portions of the plurality of negative electrode current collector foils are alternately overlapped and joined, the thickness of about 100 μm to 1 mm You may arrange | position between the extension parts which are going to join a copper plate.

  An extension part of a positive electrode current collector foil extending from a plurality of secondary battery cells in one battery module, and an extension part of a negative electrode current collector foil extending from a plurality of secondary battery cells in another battery module; Examples of the method of joining are ultrasonic welding and spot welding. Among these, ultrasonic welding is preferable because the bonding area can be widened and the resistance of the bonding portion can be kept as low as possible. When joining by ultrasonic welding, in order to improve the adhesiveness of a joining part, you may ultrasonically weld after inserting the copper plate etc. of thickness of about 100 micrometers-1 mm between the extension parts of a welding part.

  As shown in FIGS. 5 and 6, when connecting two arbitrary adjacent battery modules in series, the positions of the joints are dispersed in two places, so that the batteries are joined in one place. The height of the junction between the electrodes of the module can be reduced by about half. 5 and 6, each of the battery modules 310 and 320 includes six secondary battery cells, and the six secondary battery cells include the first group of three secondary battery cells and the second battery cell. Since it is divided into two groups of three secondary battery cells in the group, two battery modules composed of six secondary battery cells in which the extension part of the current collector foil is at the same position are connected in series. Compared with the case where it connects to, the total thickness of the extension part of each junction part becomes a half. For example, two sets of secondary battery cells formed using the positive electrode current collector foil 31 and the negative electrode current collector foil 32 as shown in FIG. 4B are used as the second group of secondary battery cells. By forming and replacing the secondary battery cells 313, 314, 323, and 324 of FIG. 5, the positions of the joint portions can be dispersed in three places. As a result, the height of the joint between the electrodes of the battery module can be reduced to about one third. As described above, according to the present invention, the volume of the joint between the electrodes of the battery module can be significantly reduced, and the volume of the battery case that houses the battery module can be reduced. As a result, the assembled battery can be reduced in size and the output density can be improved.

Hereinafter, each process of the manufacturing method of the assembled battery of this invention is demonstrated.
(A) Production of Secondary Battery Cell This step is a step of forming a secondary battery cell including a laminate of at least a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil. The positive electrode current collector foil and the negative electrode current collector foil each have first to Nth groups (N is 2) each having an extending portion extending outward from two opposite ends of each secondary battery cell. A plurality of secondary battery cells (the integers above) (here, the positions of the extending portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the Nth group are the first group to 1 set each for each battery module. The laminate of the positive electrode current collector foil, the positive electrode layer, the solid electrolyte layer, the negative electrode layer, and the negative electrode current collector foil can be formed by a method known in the technical field. For example, the laminate is formed by forming a positive electrode layer and a negative electrode layer on a positive electrode current collector foil and a negative electrode current collector foil, respectively, laminating a solid electrolyte layer between the positive electrode layer and the negative electrode layer, and pressing in the laminating direction. Alternatively, a solid electrolyte layer is formed in advance, and a positive electrode forming material, a negative electrode forming material, a positive electrode current collector foil, and a negative electrode current collector foil are respectively arranged on the surface of the solid electrolyte layer in the stacking direction. It can be formed by pressing.

  The positive electrode current collector foil and the negative electrode current collector foil are not particularly limited as long as they are generally known as those capable of functioning as the positive electrode current collector foil and the negative electrode current collector foil. For example, what was manufactured from materials, such as aluminum, stainless steel (SUS), and iron, can be used. As an example of negative electrode current collector foil, what was manufactured from materials, such as copper, stainless steel, and iron, can be used, for example. The thickness of the positive electrode current collector foil and the negative electrode current collector foil varies depending on the constituent material of the current collector foil, the intended use of the assembled battery, the adhesion with the electrode mixture, the bondability with the current collector tab, etc. be able to. For example, when the positive electrode current collector foil is manufactured from aluminum, the thickness of the positive electrode current collector foil is typically 5 μm to 20 μm. When the negative electrode current collector foil is manufactured from copper, the thickness of the negative electrode current collector foil is typically 5 μm to 20 μm.

The positive electrode layer of the secondary battery cell is not particularly limited as long as it has a function as a positive electrode layer, and the same as that generally used in all-solid secondary batteries can be used. The positive electrode layer of the secondary battery cell is formed from a positive electrode forming material containing a positive electrode active material. The positive electrode forming material may further include other solid materials (for example, solid electrolytes (for example, sulfide-based solid electrolytes, polymer electrolytes, oxide-based solid electrolytes)), conductive assistants (for example, carbon black, carbon fibers) as necessary. Etc.), SUS powder, Ni powder, etc.). The positive electrode active material is not particularly limited as long as it shows a noble potential as compared with the charge / discharge potential or oxidation-reduction potential of the negative electrode active material. Examples of the positive electrode active material include LiCoO ₂ , LiMnO ₂ , Li ₂ NiMn ₃ O ₈ , LiVO ₂ , LiCrO ₂ , LiFePO ₄ , LiCoPO ₄ , LiNiO ₂ , LiNi _1/3 Co _1/3 Mn _1/3 O _2. Etc. The shape of the positive electrode active material is preferably particulate. The average particle diameter of the positive electrode active material is typically 0.1 μm to 20 μm, preferably 1 μm to 10 μm. The content of the positive electrode active material in the positive electrode layer is typically 50 to 80% by mass. Specific examples of the conductive assistant include carbon black (for example, acetylene black and ketjen black), carbon fiber, and the like. The binder is preferably chemically and electrically stable. Specific examples thereof include fluorine-based binder components such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), and styrene-butadiene rubber ( And rubber-based binder components such as SBR) and butadiene rubber (BR). The content of the binder in the positive electrode layer is preferably less as long as the positive electrode active material and the like can be stably fixed, and is typically 1 to 10% by mass based on the total mass of the positive electrode layer. Although the thickness of a positive electrode layer is not specifically limited, Usually, they are 30 micrometers-100 micrometers.

The solid electrolyte layer is not particularly limited as long as it is made of a material that can function as a solid electrolyte. As the solid electrolyte used in the solid electrolyte layer, the same one as that generally used in an all-solid secondary battery can be used. Examples of solid electrolytes include, for example, sulfide-based solid electrolytes (for example, Li ₂ S—P ₂ S ₅ , Li ₂ S—SiS ₂ , Li ₂ S—GeS ₂ , Li ₂ S—Al ₂ S _3). And oxide solid electrolytes (for example, LiPON, LAGP, LATP) and the like. The thickness of the solid electrolyte layer is not particularly limited, but is typically 1 μm to 100 μm.

  The negative electrode layer of the secondary battery cell is formed from a negative electrode forming material containing a negative electrode active material. The negative electrode forming material may further include other solid materials (for example, solid electrolytes (for example, sulfide-based solid electrolytes, polymer electrolytes, oxide-based solid electrolytes), conductive assistants (for example, carbon black, carbon fiber) as necessary. Etc.), SUS powder, Ni powder, etc.). Examples of the negative electrode active material include metal In, metal Li, Si—Li alloy, Sn—Li alloy, SnO—Li based material, and graphite. The thickness of the negative electrode layer is not particularly limited, but is typically 10 μm to 100 μm.

The solid electrolyte that can be used for the positive electrode layer and the negative electrode layer is not particularly limited as long as it has a function as a solid electrolyte. As the solid electrolyte, those similar to those generally used in all solid lithium secondary batteries can be used. Examples of solid electrolytes include, for example, sulfide-based solid electrolytes (for example, Li ₂ S—P ₂ S ₅ , Li ₂ S—SiS ₂ , Li ₂ S—GeS ₂ , Li ₂ S—Al ₂ S _3). And oxide solid electrolytes (for example, LiPON, LAGP, LATP) and the like.

(B) Production of battery module In each group of a plurality of secondary battery cells of the first group to the Nth group, a plurality of secondary battery cells are stacked through an electrical insulating layer to form a laminate. In addition, a stack of secondary battery cells of the first group to the Nth group can be stacked via an electrical insulating layer to form one battery module. By repeating these steps once or more, two or more battery modules can be prepared. For the production of a battery module, a plurality of secondary battery cells produced as described above are individually applied to an electrically insulating exterior material such as an electrically insulating material film such as polypropylene, polyethylene, or polyethylene terephthalate as necessary. It may be housed and stacked, or a plurality of secondary battery cells may be stacked via an electrical insulating layer without being housed in the exterior material. However, it is necessary that the extending portions of the positive electrode current collector foil and the negative electrode current collector foil extend to the outside of the secondary battery cell. A laminated body obtained by laminating a plurality of secondary battery cells via an electrical insulating layer is then placed so as not to shift its position and pressed (for example, a surface press, a roll press, a hydraulic press, In addition, the battery module can be obtained by bonding the secondary battery cells to each other with a press pressure. Note that “stacking a plurality of secondary battery cells via an electrical insulating layer” includes a case where a plurality of secondary batteries are individually housed and stacked in an electrically insulating exterior material such as an electrically insulating material film. .

  The arrangement of the plurality of secondary battery cells in each battery module is such that when an assembled battery is produced by connecting them in series, in any adjacent battery module, a plurality of first to N-th groups in one battery module. A plurality of current collector foils in which the positive electrode current collector foil and the negative electrode current collector foil of the secondary battery cell have different polarities of the plurality of secondary battery cells of the first group to the Nth group in the other battery module, respectively. A combination of the first group to the Nth group is selected so as to overlap with the extending portion. The shape and number of secondary battery cells included in each group of the plurality of secondary battery cells of the first group to the Nth group, the shape, size, and position of the positive electrode current collector foil and the extension part of the negative electrode current collector foil As described above, as described above, the extension portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the Nth group in one battery module are respectively the extension portions. As long as it is connected to the extending portions of the plurality of current collector foils having different polarities of the plurality of secondary battery cells of the first group to the Nth group in the other battery module existing at a position overlapping with respect to However, a person skilled in the art can select the assembled battery obtained by connecting a plurality of battery modules in series so that the performance can be maximized.

(C) Production of battery pack A battery pack can be produced by connecting a plurality of battery modules produced as described above in series and housing them in a battery case. In manufacturing the assembled battery, for example, first, a plurality of battery modules are prepared, and in any adjacent battery module, the stacking directions of the plurality of secondary battery cells in each battery module are the same and connected in series. They are arranged side by side so that the extending portions of the current collector foils to be overlapped. Next, as described above, the electrode current collector foils having different polarities are joined together by a joining method such as ultrasonic welding, and a plurality of battery modules are connected in series. In any adjacent battery module, the extension portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the Nth group in one battery module are respectively connected to the extension portions. Two or more battery modules by joining to the extending portions of the plurality of current collector foils having different polarities of the plurality of secondary battery cells of the first group to the Nth group in the other battery module existing at the overlapping position Can be connected in series. A plurality of battery modules connected in series, and then a positive current collecting tab and a negative current collecting tab are joined to the battery module located in the outermost layer, respectively, and the tip of the current collecting tab protrudes to the outside. An assembled battery can be obtained by covering those battery modules with an exterior (laminate, can, etc.) member and placing the inside in a vacuum.

  The assembled battery of the present invention can be suitably used as a power source for a motor mounted on a vehicle such as a hybrid vehicle or an electric vehicle.

110, 120 Secondary battery cell 111, 112, 113 Current collector foil extension 121, 122, 123 Current collector foil extension 20 Secondary battery cell 21 Positive electrode current collector foil 21
22 Positive electrode layer 23 Solid electrolyte layer 24 Negative electrode layer 24
25 Negative electrode current collector foil 25
21a Extension part of positive electrode current collector foil 25a Extension part of negative electrode current collector foil 31 Positive electrode current collector foil 31a Extension part 32 Positive electrode current collector foil 32a Extension part 310, 320, 330 Battery module 311, 312, 313 1st Group of secondary battery cells 321, 322, 323 first group of secondary battery cells 314, 315, 316 second group of secondary battery cells 324, 325, 326 second group of secondary battery cells 311 a, 312 a, 313 a Extension part of positive electrode current collector foil 314a, 315a, 316a Extension part of positive electrode current collector foil 311b, 312b, 313b Extension part of negative electrode current collector foil 314b, 315b, 316b Extension part of negative electrode current collector foil 321a, 322a 323a Positive current collector foil extension 324a, 325a, 326a Positive current collector foil extension 321b, 322b, 323b Negative current collector foil extension 324b, 325 326b Extension part of negative electrode current collector foil 331, 332, 333 First group of secondary battery cells 334, 335, 336 Second group of secondary battery cells 331a, 332a, 333a Extension part of positive electrode current collector foil 331b 332b, 333b Extension part of negative electrode current collector foil 334b, 335b, 336b Extension part of negative electrode current collector foil

Claims (4)

An assembled battery including two or more battery modules connected in series,
Each battery module includes a plurality of secondary battery cells of the first group to the Nth group (N is an integer of 2 or more), and the plurality of secondary battery cells of the first group to the Nth group are respectively in the thickness direction. A positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil, which are laminated in order, each of the positive electrode current collector foil and the negative electrode current collector foil of each secondary battery cell, Each having an extending portion extending outward from the end portion;
In each group of the plurality of secondary battery cells of each of the first group to the Nth group of each battery module, the plurality of secondary batteries are stacked via an electrical insulating layer to form a stacked body, A stack of a plurality of secondary battery cells of Group 1 to Group N is stacked via an electrical insulating layer,
In each battery module, the positions of the extending portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the N group are different from each other between the first group to the N group,
In any two adjacent battery modules, the extension portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the Nth group in one battery module are respectively extended. A plurality of secondary battery cells of the first group to the N-th group in the other battery module existing at a position overlapping with the portion are connected to the extending portions of the current collector foils having different polarities, Assembled battery.   N is 2, and in each of the secondary battery cells of the first group and the second group, the extension part of the positive electrode current collector foil and the extension part of the negative electrode current collector foil are at diagonal positions. The assembled battery as described. A method of manufacturing an assembled battery including two or more battery modules connected in series,
(A) Each secondary battery cell includes a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil that are sequentially stacked in the thickness direction. , A plurality of secondary battery cells in the first group to the Nth group (N is an integer of 2 or more) each having an extending portion extending outward from two opposite ends of each secondary battery cell. Here, the positions of the extending portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells in the first group to the N group are different from each other in the first group to the N group). Prepare one set for each module,
(B) In each group of the plurality of secondary battery cells of the first group to the Nth group, a plurality of secondary battery cells are stacked via an electrical insulating layer to form a stacked body, and the first obtained A battery module is formed by laminating a stack of secondary battery cells of group N to group N via an electrical insulating layer,
(C) Prepare two or more battery modules by repeating the steps (A) and (B) at least once,
(D) In any adjacent battery module, the extension portions of the positive electrode current collector foil and the negative electrode current collector foil of the plurality of secondary battery cells of the first group to the Nth group in one battery module are respectively Two or more by connecting with the extension part of several current collector foil from which the polarity of the several secondary battery cell of the 1st group-N group in the other battery module which exists in the position which overlaps with an existing part differs Connecting battery modules in series,
A method for producing an assembled battery, comprising:   N is 2, and in each of the secondary battery cells of the first group and the second group, the extension part of the positive electrode current collector foil and the extension part of the negative electrode current collector foil are at diagonal positions. The manufacturing method of the assembled battery as described.

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