Laminate type battery, battery stack, and method for manufacturing laminate type battery

Abstract

To provide a laminated battery capable of improving structural efficiency.SOLUTION: The laminate type battery of the present disclosure is a laminate type battery. The laminated battery includes an electrode body, a side member disposed on a side surface of the electrode body, a laminate sheet covering the electrode body, and a tab film disposed between the side member and the laminate sheet. The side surface member and the laminate sheet are welded via the tab film. The tab film has an inner excess resin portion protruding from an end of the side member on the electrode body side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a laminated battery, a battery stack, and a method for manufacturing a laminated battery. [Background technology]

[0002] Laminated batteries are known as thin and lightweight batteries. In laminated batteries, an electrode assembly is housed in an exterior body made of a laminate sheet (hereinafter also referred to as a "laminated exterior body").

[0003] Patent Document 1 discloses a laminated battery. As shown in FIG. 14, the laminated battery 900 disclosed in Patent Document 1 includes an electrode assembly 910, a laminated exterior body 920, and a tab film 930. The electrode assembly 910 includes an electrode body portion 911, a flat terminal portion 912, and a tab lead portion 913 that electrically connects the electrode body portion 911 and the terminal portion 912. The tab lead portion 913 is attached to a main surface S912 of the terminal portion 912. The laminated exterior body 920 includes a bag-shaped portion 920A that houses the electrode body portion 911 and an edge portion 920B that sandwiches and seals the terminal portion 912. The laminated exterior body 920 is formed by laminating a thermoplastic resin layer 921, a metal layer 922, and an exterior resin layer 923 in this order. The tab film 930 is made of a thermoplastic resin. The tab film 930 is sandwiched between the terminal portion 912 and the thermoplastic resin layer 921, and has a welding portion 930A that welds the terminal portion 912 to the edge portion 920B. A side surface S920 of the laminate exterior body 920 on the terminal portion 912 side is exposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-194949 Summary of the Invention [Problem to be solved by the invention]

[0005] In the laminated battery 900 disclosed in Patent Document 1, the metal layer 922 on the side surface S920 of the laminated outer casing 920 is exposed. Therefore, to ensure electrical insulation between the terminal portion 912 and the metal layer 922 (e.g., to prevent creeping discharge between the terminal portion 912 and the metal layer 922), it is necessary to ensure a creeping distance L900 (see FIG. 14 ) between the terminal portion 912 and the metal layer 922. The creeping distance L900 does not function as a power-generating element of the laminated battery 900. In other words, ensuring the creeping distance L900 may reduce the structural efficiency of the laminated battery 900. "Structural efficiency" refers to the ratio of the total volume of the power-generating elements included in the battery to the total volume of the battery.

[0006] The present disclosure has been made in consideration of the above circumstances. An object of one embodiment of the present disclosure is to provide a laminated battery and a battery stack that can improve structural efficiency. Another problem to be solved by another embodiment of the present disclosure is to provide a method for manufacturing a laminated battery that can manufacture a laminated battery that can improve structural efficiency. [Means for solving the problem]

[0007] The means for solving the above problems include the following embodiments.

[0008] <1> A laminated battery of a first aspect of the present disclosure is a laminated battery comprising an electrode body, a side member arranged on a side of the electrode body, a laminate sheet covering the electrode body, and a side resin member attached to the side of the laminate sheet facing the side member, wherein the side member and the laminate sheet are welded together, the laminate sheet has a metal layer, and the side resin member covers the metal layer on the side of the laminate sheet.

[0009] In the present disclosure, the "side surface of the laminate sheet on the side of the side member" refers to the surface adjacent to the welding surface of the laminate sheet.

[0010] In the first embodiment, the side resin member covers the metal layer (hereinafter also referred to as the "side metal layer") on the side of the laminate sheet facing the side member. Therefore, electrical insulation between the side member and the side metal layer can be ensured without considering the creepage distance between the side member and the side metal layer. In other words, in the first embodiment, the volume of a portion that does not function as a power generating element of the laminate battery (for example, the volume of a portion necessary to ensure the creepage distance L900 (see FIG. 14)) can be omitted. As a result, the laminate battery of the first embodiment can improve structural efficiency compared to conventional laminate batteries.

[0011] <2> In a second aspect of the present disclosure, there is provided a laminated battery, wherein the side member and the laminate sheet are directly welded together. <1> 1. The laminated battery according to claim 1.

[0012] In the present disclosure, "the side member and the laminate sheet are directly welded together" means that no other member is interposed between the side member and the laminate sheet.

[0013] In the second embodiment, the side surface member and the laminate sheet are directly welded together. Therefore, the sealing area of ​​the side surface member (i.e., the contact area between the side surface member and the laminate sheet) is larger. This prevents moisture (water vapor) from penetrating into the electrode assembly from the outside of the laminate battery. As a result, the laminate battery of the second embodiment can prevent deterioration of battery performance and has excellent adhesion between the side surface member and the laminate sheet.

[0014] <3> A laminated battery according to a third aspect of the present disclosure further includes a resin film disposed between the side surface member and the laminate sheet, and the side surface member and the laminate sheet are welded together via the resin film. <1> 1. The laminated battery according to claim 1.

[0015] In the third embodiment, the side surface member and the laminate sheet are welded together via a resin film, resulting in excellent productivity of the laminated battery of the third embodiment.

[0016] <4> In a fourth aspect of the present disclosure, there is provided a laminated battery, wherein the side resin member includes the resin film. <3> 1. The laminated battery according to claim 1.

[0017] In a fourth aspect, the side surface resin member includes a resin film, which ensures electrical insulation between the side surface member and the side surface metal layer.

[0018] <5> In a fifth aspect of the present disclosure, there is provided a laminated battery, wherein the side resin member does not include the resin film. <3> 1. The laminated battery according to claim 1.

[0019] In the fifth aspect, the side surface resin member does not include a resin film, that is, in the fifth aspect, electrical insulation between the side surface member and the side surface metal layer is ensured by the side surface resin member, which is different from the resin film.

[0020] <6> In a sixth aspect of the present disclosure, there is provided a laminated battery, wherein the resin film has an inner excess resin portion protruding from an end of the side member on the electrode body side. <3> ~ <5> The laminated battery according to any one of the above items.

[0021] In a sixth aspect, the resin film has an inner excess resin portion that protrudes from the end of the side member on the electrode body side. In other words, the laminated battery has a space on the side of the inner excess resin portion opposite the laminate sheet side in the thickness direction of the resin film. This makes the inner excess resin portion more likely to expand in volume on the side opposite the laminate sheet side when the laminated battery is exposed to high temperatures. In other words, the stress that the laminate sheet receives due to the volume expansion of the inner excess resin portion is less severe than in the past. As a result, the laminated battery of the sixth aspect has excellent structural reliability of the laminate sheet even when exposed to high-temperature environments.

[0022] <7> A laminated battery according to a seventh aspect of the present disclosure is characterized in that the electrode body includes at least one unit electrode body, and the unit electrode body is formed by laminating a positive electrode current collector, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector in this order. <1> ~ <6> The laminated battery according to any one of the above items.

[0023] In the seventh aspect, the unit electrode body is formed by laminating a positive electrode current collector, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector in this order, resulting in a laminated battery of the seventh aspect with a higher energy density.

[0024] <8> In an eighth aspect of the present disclosure, there is provided a laminated battery, wherein the side surface member is a terminal, the terminal has an opposing surface that faces the side surface of the electrode body, and the opposing surface is electrically connected to the electrode body. <1> ~ <7> The laminated battery according to any one of the above items.

[0025] Conventionally, flat terminals have been used as terminals. In flat terminals, the side surface opposite the main surface of the terminal is the surface facing the electrode body of the terminal. The area of ​​the side surface of the terminal is small. Therefore, the electrode body is electrically connected to the main surface of the terminal. In the eighth aspect, the terminal has an opposing surface that faces the side surface of the electrode body, and the opposing surface is electrically connected to the electrode body. As a result, it is not necessary to ensure a sufficient length in the direction perpendicular to the opposing surface of the terminal (in other words, the length of the main surface in the direction perpendicular to the opposing surface of a conventional flat terminal) to electrically connect the terminal and the electrode body. In other words, in the eighth aspect, the length in the direction perpendicular to the opposing surface of the terminal can be made shorter than conventional. As a result, the structural efficiency of the laminated battery of the eighth aspect is superior.

[0026] <9> A laminated battery according to a ninth aspect of the present disclosure includes a pair of the terminals facing each other via the electrode body, <8> 1. The laminated battery according to claim 1.

[0027] <10> A battery stack according to a tenth aspect of the present disclosure includes a plurality of the electrode bodies stacked in a direction parallel to the side surfaces of the electrode bodies. <9> and a plurality of inter-battery connection terminals electrically connected to the terminals and connecting a plurality of the laminated batteries in series.

[0028] <11> A laminated battery of an eleventh aspect of the present disclosure is a manufacturing method for a laminated battery, the laminated battery comprising an electrode body, a side member arranged on a side of the electrode body, a laminate sheet covering the electrode body, and a side resin member attached to the side of the laminate sheet facing the side member, the side member and the laminate sheet being directly welded together, the laminate sheet having a metal layer, the manufacturing method for a laminated battery including forming the side resin member on the side of the laminate sheet so as to cover the metal layer on the side of the laminate sheet, and welding the side member and the laminate sheet together with a heat bar.

[0029] According to the method for producing a laminated battery of the eleventh aspect, it is possible to suppress deterioration of battery performance and obtain a laminated battery having superior adhesion between the side surface member and the laminate sheet.

[0030] <12> A laminated battery according to a first aspect of the present disclosure is a method for manufacturing a laminated battery, the laminated battery comprising an electrode body, a side surface member disposed on a side surface of the electrode body, a laminate sheet covering the electrode body, and a side surface resin member attached to the side surface of the laminate sheet facing the side surface member, the side surface resin member including a resin film disposed between the side surface member and the laminate sheet, the side surface member and the laminate sheet being welded together via the resin film, and the laminate sheet having a metal layer a resin film is disposed on the side member so that the side resin member covers the metal layer on the side of the laminate sheet and the resin film has a protruding portion protruding from the side of the laminate sheet; welding the side member and the laminate sheet together with the resin film interposed therebetween using a heat bar; and deforming the protruding portion by utilizing residual heat of the resin film generated when welding the side member and the laminate sheet to form the side resin member.

[0031] In the present disclosure, "utilizing the residual heat of the resin film when welding the side member and the laminate sheet" means that the temperature of the resin film is a temperature equal to or higher than the glass transition temperature or softening point of the resin contained in the resin film.

[0032] According to the method for manufacturing a laminated battery of the eleventh aspect, a laminated battery that can improve structural efficiency can be manufactured efficiently. [Effects of the Invention]

[0033] According to the present disclosure, a laminated battery and a battery stack are provided that can improve structural efficiency. According to the present disclosure, a method for manufacturing a laminated battery is provided that can manufacture a laminated battery that can improve structural efficiency. [Brief explanation of the drawings]

[0034] [Figure 1]FIG. 1 is a perspective view showing the appearance of a laminated battery according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of the laminated battery of FIG. 1 taken along line C2-C2. [Figure 3] 3 is a partially enlarged cross-sectional view of the laminated battery of FIG. 1 taken along line C3-C3. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of a unit electrode body according to the first embodiment of the present disclosure. [Figure 5] FIG. 5 is a perspective view showing the appearance of the battery stack according to the first embodiment of the present disclosure. [Figure 6] FIG. 6 is a perspective view showing the appearance of a laminated battery according to a second embodiment of the present disclosure. [Figure 7] FIG. 7 is a cross-sectional view of the laminated battery of FIG. 6 taken along line C7-C7. [Figure 8] 8 is a partially enlarged cross-sectional view of the laminated battery of FIG. 6 taken along line C8-C8. [Figure 9] FIG. 9 is a diagram for explaining a method for manufacturing a laminated battery according to the second embodiment of the present disclosure. [Figure 10] FIG. 10 is a perspective view showing the appearance of a laminated battery according to a third embodiment of the present disclosure. [Figure 11] FIG. 11 is a cross-sectional view of the laminated battery of FIG. 10 taken along the line C11-C11. [Figure 12] 12 is a partially enlarged cross-sectional view of the laminated battery of FIG. 10 taken along the line C12-C12. [Figure 13] FIG. 13 is a perspective view showing the appearance of a battery stack according to a fourth embodiment of the present disclosure. [Figure 14] FIG. 14 is a cross-sectional view of a conventional laminated battery. DETAILED DESCRIPTION OF THE INVENTION

[0035] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0036] Hereinafter, embodiments of a laminated battery, a battery stack, and a method for manufacturing a laminated battery according to the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0037] (1) First embodiment (1.1) Laminated battery As shown in FIG. 1, a laminated battery 1A according to a first embodiment of the present disclosure includes a side surface resin member 10A, a pair of terminals 20 which are an example of side surface members, a laminate sheet 30, and an electrode assembly 40. One of the pair of terminals 20 is a positive electrode terminal. The other of the pair of terminals 20 is a negative electrode terminal. The electrode assembly 40 is a rectangular parallelepiped.

[0038] In the first embodiment, one longitudinal side of the main surface of the electrode body 40 is defined as the positive X-axis direction (hereinafter also referred to as the "front side"), and the opposite side is defined as the negative X-axis direction (hereinafter also referred to as the "rear side"). One lateral side of the main surface of the electrode body 40 is defined as the positive Y-axis direction (hereinafter also referred to as the "right side"), and the opposite side is defined as the negative Y-axis direction (hereinafter also referred to as the "left side"). One thickness direction side of the electrode body 40 is defined as the positive Z-axis direction (hereinafter also referred to as the "upper side"), and the opposite side is defined as the negative Z-axis direction (hereinafter also referred to as the "lower side"). The X-axis, Y-axis, and Z-axis are perpendicular to each other. Note that these directions do not limit the orientation of the laminated battery 1A of the present disclosure during use.

[0039] As shown in FIG. 2 , the pair of terminals 20 are arranged opposite each other with the electrode body 40 interposed therebetween. Specifically, one of the pair of terminals 20 is arranged on the front surface SA40 of the electrode body 40. The other of the pair of terminals 20 is arranged on the rear surface SB40 of the electrode body 40. Each of the pair of terminals 20 is electrically connected to the electrode body 40. The laminate sheet 30 covers the electrode body 40. The side surface resin member 10A is attached to the side surface S30 of the laminate sheet 30 on the terminal 20 side. Specifically, the side surface resin member 10A covers the entire side surface S30 of the laminate sheet 30. Each of the pair of terminals 20 and the laminate sheet 30 are directly welded together. The electrode body 40 is sealed by the pair of terminals 20 and the laminate sheet 30.

[0040] In the first embodiment, the laminated battery 1A is a laminated lithium secondary battery using a solid electrolyte. Applications of the laminated battery 1A include, for example, a power source for an in-vehicle device, a power source for an information processing device (for example, a personal computer, a smartphone, etc.), a power source for storing electricity, etc.

[0041] (1.1.1) Terminal The terminal 20 is a rectangular parallelepiped object with its longitudinal direction in the left-right direction (Y-axis direction) and its lateral direction in the front-rear direction (X-axis direction).

[0042] As shown in FIG. 2, one of the pair of terminals 20 has an opposing surface SA20 that faces the front surface SA40 of the electrode body 40. The other of the pair of terminals 20 has an opposing surface SA20 that faces the rear surface SB40 of the electrode body 40. The opposing surface SA20 of each of the pair of terminals 20 is electrically connected to the electrode body 40. The length L1 (see FIG. 2) of the opposing surface SA20 of each of the pair of terminals 20 in the up-down direction (Z-axis direction) is longer than that of conventional terminals. The length L1 is, for example, 0.1 cm or more. The length L2 (see FIG. 2) of each of the pair of terminals 20 in the front-to-back direction (X-axis direction) is shorter than that of conventional terminals. The length L2 is, for example, 2.0 cm or less. The length L3 (see FIG. 3) of each of the pair of terminals 20 in the left-to-right direction (Y-axis direction) is, for example, 4.0 cm or more. The terminal 20 may be made of a metal (for example, stainless steel (SUS)).

[0043] (1.1.2) Laminated sheet The laminate sheet 30 covers the electrode body 40 and seals the electrode body 40 together with the pair of terminals 20. One laminate sheet 30 is used. The single laminate sheet 30 is folded to function as a laminate exterior material.

[0044] 2, the laminate sheet 30 has a metal layer 31, a first resin layer 32, and a second resin layer 33. The first resin layer 32, the metal layer 31, and the second resin layer 33 are stacked in this order in the vertical direction (Z-axis direction). The first resin layer 32 is disposed on the electrode body 40 side of the second resin layer 33.

[0045] The metal layer 31 blocks the passage of gas (for example, moisture, air, etc.) between the outside and the inside of the laminated battery 1 A. The material of the metal layer 31 is a metal (for example, aluminum, etc.). The first resin layer 32 enables welding of the terminal 20 and the laminate sheet 30, and electrically insulates the pair of terminals 20 and electrode body 40 from the metal layer 31. The first resin layer 32 is made of a first thermoplastic resin composition. The first thermoplastic resin composition includes a first thermoplastic resin. Examples of the first thermoplastic resin include olefin-based resins (e.g., polypropylene, polyethylene, etc.), polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polystyrene-based resins, acrylonitrile-styrene copolymer (AS) resins, acrylonitrile-butadiene-styrene copolymer (ABS) resins, polyester-based resins, poly(meth)acrylic resins, polyvinyl alcohol, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polyacetal-based resins, fluorine-based resins, polysulfone-based resins, polyphenylene sulfide resins, and polyketone-based resins. Among these, it is preferable that the first thermoplastic resin include polypropylene. The first thermoplastic resin composition may include a compounding agent as needed. Examples of the compounding agents include heat stabilizers, antioxidants, pigments, weathering agents, flame retardants, plasticizers, dispersants, lubricants, release agents, and antistatic agents. The second resin layer 33 improves the durability of the laminate sheet 30. The second resin layer 33 is made of a second thermoplastic resin composition. The second thermoplastic resin composition is not particularly limited, and examples include those similar to those exemplified as the first thermoplastic resin. The second thermoplastic resin composition may be the same as or different from the first thermoplastic resin composition. In particular, the resin contained in the second thermoplastic resin preferably has high affinity with the resin contained in the electrical insulating resin composition of the side resin member 10A (described later), from the viewpoint of ensuring that the side resin member 10A reliably covers the metal layer 31 on the side surface S30 of the laminate sheet 30. Specifically, the difference between the melting point or glass transition temperature of the resin contained in the second thermoplastic resin and the melting point or glass transition temperature of the resin contained in the electrical insulating resin composition of the side resin member 10A (described later) is preferably 15°C or less. The second thermoplastic resin may include polyethylene terephthalate.

[0046] Terminal 20 has an outer surface SB20 on the opposite side of facing surface SA20 in the front-to-rear direction (X-axis direction). Side surface S30 of laminate sheet 30 and outer surface SB20 of terminal 20 are arranged to be flush with each other, as shown in Figures 2 and 3. That is, in the first embodiment, the creepage distance between metal layer 31 of laminate sheet 30 and terminal 20 is 0 mm.

[0047] (1.1.3) Side resin parts 2 and 3, the side surface resin member 10A electrically insulates the terminal 20 from the metal layer 31 on the side surface S30 of the laminate sheet 30. The side surface resin member 10A covers the metal layer 31 on the side surface S30 of the laminate sheet 30. The side surface resin member 10A is welded to each of the first resin layer 32 and the second resin layer 33 on the side surface S30 of the laminate sheet 30.

[0048] As shown in FIG. 2, in a cross section of the laminated battery 1A cut along the front-rear direction (X-axis direction) perpendicular to the front surface SA40 of the electrode body 40, the side resin member 10A preferably has the following dimensions: In the vertical direction (Z-axis direction), the length LA1 (see Figure 2) of the portion of the side resin member 10A protruding from the end EA33 of the second resin layer 33 opposite the electrode body 40 is preferably less than 0.1 mm, and more preferably 0 mm. In the vertical direction (Z-axis direction), it is more preferable that the length LA2 (see Figure 2) of the portion of the side resin member 10A protruding from the end EA32 of the first resin layer 32 on the electrode body 40 side is 0 mm, from the viewpoint of ensuring a wider contact area between the terminal 20 and the laminate sheet 30 (i.e., from the viewpoint of reliably preventing the side resin member 10A from entering between the terminal 20 and the laminate sheet 30). In the front-rear direction (X-axis direction), the length LA3 (see FIG. 2) of the side resin member 10A from the side surface S30 of the laminate sheet 30 is preferably less than 1 mm from the standpoint of efficiently connecting the laminated batteries 1A to each other.

[0049] As shown in FIG. 3, in a cross section of the laminated battery 1A cut along the front-rear direction (X-axis direction) perpendicular to the front surface SA40 of the electrode body 40, the side resin member 10A preferably has the following dimensions: In the left-right direction (Y-axis direction), the length LA4 (see FIG. 3) of the portion of the side surface resin member 10A that protrudes from the end EB33 of the second resin layer 33 opposite to the electrode body 40 is preferably less than 0.1 mm, more preferably 0 mm. The length LA4 may be the same as or different from the length LA1 (see FIG. 2). In the left-right direction (Y-axis direction), the length LA5 (see FIG. 3) of the portion of side surface resin member 10A protruding from end EB32 of first resin layer 32 on the electrode body 40 side is more preferably 0 mm, from the viewpoint of ensuring a wider contact area between terminal 20 and laminate sheet 30 (i.e., from the viewpoint of reliably preventing side surface resin member 10A from entering between terminal 20 and laminate sheet 30). Length LA5 may be the same as or different from length LA2 (see FIG. 2). In the front-rear direction (X-axis direction), the length LA6 (see FIG. 3) of the side resin member 10A from the side surface S30 of the laminate sheet 30 is preferably less than 1 mm from the viewpoint of efficiently connecting the laminate-type batteries 1A to each other. The length LA6 may be the same as or different from the length LA3 (see FIG. 2).

[0050] The side resin member 10A is made of a cured product of an electrical insulating resin composition (e.g., a photocurable resin composition, a thermosetting resin composition, or a third thermoplastic resin composition). The photocurable resin composition contains a compound having multiple photopolymerizable carbon-carbon double bonds (e.g., a (meth)acrylic resin composition, an epoxy resin composition, etc.) and may contain a photopolymerization initiator (e.g., a benzophenone-based, anthraquinone-based, etc.) as needed. The thermosetting resin composition contains a resin (e.g., an acrylic resin or a polyester resin) having two or more crosslinkable functional groups (e.g., a hydroxyl group, an epoxy group, an isocyanate group, or a carboxyl group) per molecule and may contain a crosslinker (e.g., an amino resin, a polyisocyanate compound, or a carboxyl group-containing compound) as needed. Examples of the third thermoplastic resin composition include those similar to those exemplified as the first thermoplastic resin. The third thermoplastic resin composition may be the same as or different from the first thermoplastic resin composition. In particular, in the first embodiment, from the viewpoint of ensuring the adhesiveness of the terminal 20, it is preferable that the third thermoplastic resin composition is the same as the first thermoplastic resin composition.

[0051] (1.1.4) Electrode body The electrode assembly 40 functions as a power generating element of the laminated battery 1A.

[0052] The electrode assembly 40 has a plurality of unit electrode bodies 41 and a pair of current collecting tabs 42. One of the pair of current collecting tabs 42 is a positive electrode current collecting tab and is electrically connected to a positive electrode terminal. The other of the pair of current collecting tabs 42 is a negative electrode current collecting tab and is electrically connected to a negative electrode terminal. Each of the pair of current collecting tabs 42 is electrically connected to a plurality of unit electrode bodies 41.

[0053] The plurality of unit electrode bodies 41 are rectangular parallelepiped objects. In the first embodiment, the length L4 (see FIG. 2) of the plurality of unit electrode bodies 41 in the up-down direction (Z-axis direction) is longer than the length L1 (see FIG. 2) of each opposing surface SA20 of the pair of terminals 20 in the up-down direction (Z-axis direction). The length L5 (see FIG. 3) of the plurality of unit electrode bodies 41 in the left-right direction (Y-axis direction) is longer than the length L3 (see FIG. 3) of each opposing surface SA20 of the pair of terminals 20 in the left-right direction (Y-axis direction).

[0054] (1.1.4.1)Battery structure The unit electrode body 41 includes a so-called all-solid-state battery that uses an inorganic solid electrolyte as the electrolyte, and the solid electrolyte may contain an electrolytic solution in an amount of less than 10 mass % relative to the total amount of the electrolyte. The solid electrolyte may also be a composite solid electrolyte that contains an inorganic solid electrolyte and a polymer electrolyte. The structure of the electrode unit 41 may be a structure in which a positive electrode current collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector are stacked in this order along the vertical direction (Z-axis direction), for example, as shown in FIG. 4. The solid electrolyte layer B in FIG. 4 may have a two-layer structure. FIG. 4 is a schematic cross-sectional view showing an example of the electrode unit 41. The electrode unit 41 shown in FIG. 4 includes a negative electrode including a negative electrode current collector 410 and a negative electrode layer A, a solid electrolyte layer B, and a positive electrode including a positive electrode current collector 411 and a positive electrode layer C. The negative electrode layer A includes a negative electrode active material 412, a conductive additive 413, a binder 414, and a solid electrolyte 415. The positive electrode layer C includes a positive electrode active material 416, a conductive additive 417, a binder 418, and a solid electrolyte 419.

[0055] The plurality of unit electrode bodies 41 may be connected in series or in parallel.

[0056] The plurality of unit electrode bodies 41 may be configured by sealing the stacking end faces (side faces) of the stacking structure of the positive electrode layer / solid electrolyte layer / negative electrode layer with resin.

[0057] (1.1.4.1.1) Solid electrolyte layer The unit electrode body 41 includes a solid electrolyte layer. The solid electrolyte layer preferably includes one selected from the group consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte.

[0058] The sulfide solid electrolyte preferably contains sulfur (S) as the main anion element, and further preferably contains, for example, Li and / or A. The A element is at least one selected from the group consisting of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In. The sulfide solid electrolyte may further contain at least one of O and a halogen element. Examples of the halogen element (X) include F, Cl, Br, and I. The composition of the sulfide solid electrolyte is not particularly limited, and examples include xLiS·(100-x)P2S5 (70≦x≦80), yLiI·zLiBr·(100-yz)(xLiS·(1-x)P2S5) (0.7≦x≦0.8, 0≦y≦30, 0≦z≦30). The sulfide solid electrolyte may have a composition represented by the following general formula (1): Formula (1): Li 4-x Ge 1-x P x S4(0 <x<1) In formula (1), at least a portion of the Ge may be substituted with at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. At least a portion of the P may be substituted with at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. At least a portion of the Li may be substituted with at least one selected from the group consisting of Na, K, Mg, Ca, and Zn. At least a portion of the S may be substituted with a halogen. The halogen is at least one of F, Cl, Br, and I.

[0059] As the oxide solid electrolyte, it is preferable to contain oxygen (O) as the main component of the anion element. For example, it may contain Li, Q element (Q represents at least one of Nb, B, Al, Si, P, Ti, Zr, Mo, W, and S), and O. Examples of the oxide solid electrolyte include garnet-type solid electrolyte, perovskite-type solid electrolyte, NASICON-type solid electrolyte, Li-P-O-based solid electrolyte, Li-B-O-based solid electrolyte, and the like. Examples of the garnet-type solid electrolyte include, for example, Li7La3Zr2O 12 、Li 7-x La3(Zr 2-x Nb x )O 12 (0 ≦ x ≦ 2), Li5La3Nb2O 12 and the like. Examples of the perovskite-type solid electrolyte include, for example, (Li, La)TiO3, (Li, La)NbO3, (Li, Sr)(Ta, Zr)O3, and the like. Examples of the NASICON-type solid electrolyte include, for example, Li(Al, Ti)(PO4)3, Li(Al, Ga)(PO4)3, and the like. Examples of the Li-P-O-based solid electrolyte include Li3PO4, LIPON (a compound in which a part of O in Li3PO4 is substituted by N), and examples of the Li-B-O-based solid electrolyte include Li3BO3, a compound in which a part of O in Li3BO3 is substituted by C, and the like.

[0060] As the halide solid electrolyte, a solid electrolyte containing Li, M, and X (M represents at least one of Ti, Al, and Y, and X represents F, Cl, or Br) is suitable. Specifically, Li 6-3z Y z X6 (X represents Cl or Br, and z satisfies 0 < z < 2), Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≦ 1.5) is preferable. Among Li 6-3z Y z X6, Li3YX6 (X represents Cl or Br) is more preferable in terms of excellent lithium ion conductivity, and further, Li3YCl6 is preferable. Also, Li 6-(4-x)b (Ti 1-x Al x ) bF6 (0 < x < 1, 0 < b ≤ 1.5) is preferably included together with a solid electrolyte such as a sulfide solid electrolyte from the viewpoint of suppressing, for example, the oxidative decomposition of the sulfide solid electrolyte.

[0061] The solid electrolyte layer may have a single-layer structure or a multilayer structure of two or more layers.

[0062] The solid electrolyte layer may contain a binder or may not contain a binder. Examples of the binder that can be included in the solid electrolyte layer include, for example, vinyl halide resins, rubbers, polyolefin resins, etc. Examples of the vinyl halide resin include polyvinylidene fluoride (PVdF), a copolymer of polyvinylidene fluoride and hexafluoropropylene (PVdF-HFP), etc. Examples of the polyolefin resin include butadiene rubber (BR), acrylate butadiene rubber (ABR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (isobutylene-isoprene rubber), etc. Examples of the polyolefin resin include polyethylene, polypropylene, etc. The binder may be a diene-based rubber containing a double bond in the main chain, for example, a butadiene-based rubber in which butadiene occupies 30 mol% or more of the whole.

[0063] (1.1.4.1.2) Positive electrode layer The unit electrode body 41 includes a positive electrode layer. The positive electrode layer contains a positive electrode active material. The positive electrode layer may contain at least one of a solid electrolyte for positive electrode, a conductive assistant, and a binder, if necessary.

[0064] Preferably, the positive electrode active material includes a lithium composite oxide. The lithium composite oxide may contain at least one selected from the group consisting of F, Cl, N, S, Br, and I. Further, the lithium composite oxide may have a crystal structure belonging to at least one space group selected from the space groups R-3m, Immm, and P63-mmc (also referred to as P63mc and P6 / mmc). Further, the main arrangement of transition metal, oxygen, and lithium in the lithium composite oxide may be an O2-type structure.

[0065] Examples of lithium composite oxides having a crystal structure belonging to R-3m include Li x Me y O α X β (Me represents at least one selected from the group consisting of Mn, Co, Ni, Fe, Al, Cu, V, Nb, Mo, Ti, Cr, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, W, B, Si, and P, and X represents at least one selected from the group consisting of F, Cl, N, S, Br, and I, and satisfy the conditions 0.5≦x≦1.5, 0.5≦y≦1.0, 1≦α<2, and 0<β≦1.)

[0066] Examples of lithium composite oxides having a crystal structure belonging to Immm include Li x1 M 1 A 1 2(1.5≦x1≦2.3, M 1 contains at least one selected from the group consisting of Ni, Co, Mn, Cu and Fe, and A 1 contains at least oxygen, and A 1 The ratio of oxygen in the oxide is 85 atomic % or more. x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y (0≦x2≦0.5, 0≦y≦0.3, and at least one of x2 and y is not 0, M 1A represents at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, and M 1B represents at least one selected from the group consisting of Al, Mg, Sc, Ti, Cr, V, Zn, Ga, Zr, Mo, Nb, Ta and W, and A2 represents at least one selected from the group consisting of F, Cl, Br, S and P.

[0067] Examples of lithium composite oxides having a crystal structure belonging to P63-mmc include M1x M2 y O2 (M1 represents an alkali metal (preferably at least one of Na and K), M2 represents a transition metal (preferably at least one selected from the group consisting of Mn, Ni, Co, and Fe), and 0 < x + y ≦ 2 is satisfied.) The composite oxide represented by is mentioned.

[0068] As the lithium composite oxide having an O2-type structure, for example, Li x [Li α (Mn a Co b M c ) 1-α O2 (0.5 < x < 1.1, 0.1 < α < 0.33, 0.17 < a < 0.93, 0.03 < b < 0.50, 0.04 < c < 0.33, and M represents at least one selected from the group consisting of Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi.) The composite oxide represented by is mentioned, and specific examples include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2 and the like.

[0069] The solid electrolyte for the positive electrode preferably contains one selected from the group consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte. As the sulfide solid electrolyte, those similar to those exemplified as the sulfide solid electrolyte contained in the solid electrolyte are mentioned. As the oxide solid electrolyte, those similar to those exemplified as the oxide solid electrolyte contained in the solid electrolyte are mentioned. As the halide solid electrolyte, those similar to those exemplified as the halide solid electrolyte contained in the solid electrolyte are mentioned.

[0070] Examples of conductive additives include carbon materials, metal materials, and conductive polymer materials. Examples of carbon materials include carbon black (e.g., acetylene black, furnace black, ketjen black, etc.), fibrous carbon (e.g., vapor-grown carbon fiber, carbon nanotube, carbon nanofiber, etc.), graphite, and carbon fluoride. Examples of metallic materials include metal powder (e.g., aluminum powder, etc.), conductive whiskers (e.g., zinc oxide, potassium titanate, etc.), and conductive metal oxides (e.g., titanium oxide, etc.). Examples of conductive polymer materials include polyaniline, polypyrrole, and polythiophene. One type of conductive additive may be used alone, or two or more types may be mixed and used.

[0071] Examples of the binder include the same binders as those exemplified as the binder contained in the solid electrolyte layer.

[0072] (1.1.4.1.3) Positive electrode current collector The unit electrode body 41 includes a positive electrode current collector. The positive electrode current collector collects current from the positive electrode layer. The positive electrode current collector is disposed on the opposite side of the positive electrode layer from the solid electrolyte layer. The positive electrode current collector may be made of, for example, stainless steel, aluminum, copper, nickel, iron, titanium, or carbon, and is preferably an aluminum alloy foil or aluminum foil. The aluminum alloy foil or aluminum foil may be manufactured using powder. The positive electrode current collector may be, for example, in the form of a foil or a mesh. The positive electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer disposed on the surface thereof.

[0073] (1.1.4.1.4) Negative electrode layer The unit electrode body 41 includes a negative electrode layer. The negative electrode layer contains a negative electrode active material. The negative electrode layer may contain at least one of a negative electrode solid electrolyte, a conductive additive, and a binder, as necessary. Examples of negative electrode active materials include Li-based active materials such as metallic lithium, carbon-based active materials such as graphite, oxide-based active materials such as lithium titanate, and Si-based active materials such as elemental Si. The conductive additive, negative electrode solid electrolyte, and binder used in the negative electrode layer may be the same as those exemplified as the conductive additive contained in the positive electrode layer, the solid electrolyte contained in the solid electrolyte layer, and the binder.

[0074] (1.1.4.1.5) Negative electrode current collector The unit electrode body 41 includes a negative electrode current collector. The negative electrode current collector collects current from the negative electrode layer. The negative electrode current collector is disposed on the opposite side of the negative electrode layer from the solid electrolyte layer. The negative electrode current collector may be made of, for example, stainless steel, aluminum, copper, nickel, iron, titanium, or carbon, with copper being preferred. The negative electrode current collector may be in the form of, for example, a foil or mesh. The negative electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer disposed on the surface thereof.

[0075] (1.1.5) Action and effect As described with reference to Figures 1 to 4, the laminated battery 1A includes an electrode assembly 40, a pair of terminals 20, a laminated sheet 30, and a side surface resin member 10A. The pair of terminals 20 and the laminated sheet 30 are welded together. The side surface resin member 10A covers the metal layer 31 on the side surface S30 of the laminated sheet 30. This ensures electrical insulation between the pair of terminals 20 and the metal layer 31 on the side surface S30 of the laminate sheet 30, without considering the creepage distance between the pair of terminals 20 and the metal layer 31 on the side surface S30 of the laminate sheet 30. In other words, the volume of parts of the laminate battery 1A that do not function as power-generating elements (for example, the volume of parts necessary to ensure the creepage distance L900 (see FIG. 14)) can be eliminated. As a result, the laminate battery 1A can achieve improved structural efficiency compared to conventional laminate batteries.

[0076] As described with reference to FIGS. 1 to 4, in the laminated battery 1A, the pair of terminals 20 and the laminated sheet 30 are directly welded together. That is, the sealing area of ​​the pair of terminals 20 (i.e., the contact area between the pair of terminals 20 and the laminate sheet 30) is wider. This prevents moisture (water vapor) from penetrating from outside the laminate battery 1A into the electrode assembly 40. As a result, the laminate battery 1A can prevent deterioration of battery performance and has better adhesion between the pair of terminals 20 and the laminate sheet 30.

[0077] 1 to 4, in the laminated battery 1A, the electrode assembly 40 includes a plurality of unit electrode bodies. Each unit electrode body is formed by laminating a positive electrode current collector, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector in this order. This allows the laminated battery 1A to have a higher energy density.

[0078] As described with reference to FIGS. 1 to 4, in the laminated battery 1A, the opposing surface SA20 of the terminal 20 is electrically connected to the electrode body 40. As a result, it is not necessary to ensure a sufficient length L2 (see FIGS. 2 and 3) in the front-rear direction (X-axis direction) perpendicular to the opposing surface SA20 of the terminal 20 to electrically connect the terminal 20 and the electrode body 40. In other words, the length L2 in the front-rear direction (X-axis direction) of the terminal 20 can be made shorter than before. As a result, the structural efficiency of the laminated battery 1A is improved.

[0079] (1.2) Battery stack As shown in Fig. 5, the battery stack 2A according to the first embodiment of the present disclosure includes multiple laminated batteries 1A and multiple inter-battery connection terminals 60A. The multiple laminated batteries 1A are stacked in a vertical direction (Z-axis direction) parallel to the front surface SA40 of the electrode assembly 40. The multiple inter-battery connection terminals 60A are electrically connected to terminals 20, connecting the multiple laminated batteries 1A in series.

[0080] The inter-battery connection terminal 60A is a component (bus bar) for electrically connecting the multiple laminated batteries 1A in series. The inter-battery connection terminal 60A is a single plate-like member. The terminal 20 of the laminated battery 1A has an outer surface SB20 on the opposite side of the facing surface SA20 in the front-to-rear direction (X-axis direction). The inter-battery connection terminal 60A is attached to the outer surface SB20 of the terminal 20. The method for attaching the inter-battery connection terminal 60A is not particularly limited, and examples include methods using fastening parts and welding. Fastening parts include bolts, nuts, screws, rivets, or pins. Welding includes metal welding and brazing. The material of the inter-battery connection terminal 60A is metal (for example, stainless steel).

[0081] (1.3) Manufacturing method of laminated battery The method for manufacturing a laminated battery according to the first embodiment of the present disclosure is a method for manufacturing a laminated battery 1A. The method for manufacturing a laminated battery according to the first embodiment includes a preparation step, a covering step, a fixing step, a forming step, and a welding step. In the first embodiment, the preparation step, covering step, fixing step, forming step, and welding step are performed in this order.

[0082] (1.3.1) Preparation process In the preparation step, a structure and one laminate sheet 30 are prepared. The structure includes an electrode assembly 40 and a pair of terminals 20 electrically connected to the electrode assembly 40. The structure and the laminate sheet 30 may be prepared by any known method.

[0083] (1.3.2) Coating process In the covering step, the laminate sheet 30 is folded to cover the electrode assembly 40 included in the structure with one laminate sheet 30. The method for covering the electrode assembly 40 with the laminate sheet 30 is not particularly limited, and may be, for example, a method in which folds are formed in the laminate sheet 30 according to the shape of the electrode assembly 40 using a known method, and the laminate sheet 30 is folded along the folds.

[0084] (1.3.3) Fixing process In the fixing step, the area where the ends of the folded laminate sheet 30 overlap (hereinafter also referred to as the "overlapping area") is thermocompression-bonded to fix the shape of the laminate sheet 30 in a state where it covers the electrode body 40. The method for thermocompression-bonding the overlapping area may be any known method, and examples thereof include a method using a heat bar.

[0085] (1.3.4) Formation process In the forming step, the side surface resin member 10A is formed on the side surface S30 of the laminate sheet 30.

[0086] The method for forming the side surface resin member 10A is not particularly limited, and includes a first method, a second method, and the like. The first method includes applying a photocurable resin composition (i.e., an example of the electrical insulating resin composition for the side surface resin member 10A) to the side surface S30 of the laminate sheet 30 to form a photocurable coating film, and irradiating the photocurable coating film with light to form the side surface resin member 10A. The method for applying the photocurable resin composition is not particularly limited, and examples include a method using a dispenser, a method using an inkjet device, and a spray coating method. The light used for irradiation may be any active energy ray (e.g., visible light, ultraviolet light, X-rays, electron beams, etc.), and is appropriately selected depending on the type of photocurable resin composition, etc. Examples of light sources include metal halide lamps, high-pressure mercury lamps, xenon lamps, halogen lamps, pulsed xenon lamps, black lights (wavelength: approximately 365 nm), ultraviolet light-emitting diodes (wavelength: approximately 375 nm), and light-emitting diode lamps (wavelength: approximately 405 nm). The second method includes applying a thermosetting resin composition (i.e., an example of the electrically insulating resin composition of the side resin member 10A described above) to the side S30 of the laminate sheet 30 to form an electrically insulating coating film, and drying the electrically insulating coating film to form the side resin member 10A.

[0087] (1.3.5) Welding process In the welding process, the terminal 20 and the laminate sheet 30 are welded together using a heat bar, thereby producing a laminated battery 1A. The heating conditions of the heat bar (e.g., heating temperature, heating time, pressure, etc.) are appropriately selected depending on the material of the laminate sheet 30, etc.

[0088] (1.3.6) Action and effect As described above, the method for manufacturing the laminated battery of the first embodiment includes a forming step and a welding step. As a result, the laminated battery manufacturing method of the first embodiment can manufacture the laminated battery 1A.

[0089] (2) Second embodiment (2.1) Laminated battery The laminated battery 1B of the second embodiment of the present disclosure is similar to the laminated battery 1A of the first embodiment, except that it has a resin film that functions mainly as a side resin member. As shown in Fig. 6, the laminated battery 1B includes a side surface resin member 10B, a pair of terminals 20, a laminate sheet 30, an electrode assembly 40, and a resin film 50A (hereinafter also referred to as "tab film 50A"). The side surface resin member 10B includes the tab film 50A. The side surface resin member 10B covers the entire side surface S30 of the laminate sheet 30. Each of the pair of terminals 20 and the laminate sheet 30 are directly welded via the tab film 50A.

[0090] As shown in FIGS. 7 and 8, the side surface S30 of the laminate sheet 30 and the outer surface SB20 of the terminal 20 are not disposed so as to be flush with each other.

[0091] (2.1.1) Side resin parts 7 and 8, the side surface resin member 10B electrically insulates the terminal 20 from the metal layer 31 on the side surface S30 of the laminate sheet 30. The side surface resin member 10B covers the metal layer 31 on the side surface S30 of the laminate sheet 30. The side surface resin member 10B is welded to each of the first resin layer 32 and the second resin layer 33 on the side surface S30 of the laminate sheet 30.

[0092] As shown in FIG. 7, in a cross section of the laminated battery 1B cut along the front-rear direction (X-axis direction) perpendicular to the front surface SA40 of the electrode body 40, the side resin member 10B preferably has the following dimensions: In the vertical direction (Z-axis direction), the length LB1 (see Figure 7) of the portion of the side resin member 10B protruding from the end EA33 of the second resin layer 33 opposite the electrode body 40 is preferably less than 0.1 mm, and more preferably 0 mm. In the front-rear direction (X-axis direction), the length LB2 (see FIG. 7) of the side resin member 10B from the side surface S30 of the laminate sheet 30 is preferably less than 1 mm from the standpoint of efficiently connecting the laminated batteries 1B together.

[0093] As shown in FIG. 8, in a cross section of the laminated battery 1B cut along the front-rear direction (X-axis direction) perpendicular to the front surface SA40 of the electrode body 40, the side resin member 10B preferably has the following dimensions: In the left-right direction (Y-axis direction), the length LB3 (see FIG. 8) of the portion of the side surface resin member 10B protruding from the end EB33 of the second resin layer 33 opposite to the electrode body 40 is preferably less than 0.1 mm, more preferably 0 mm. Length LB3 may be the same as or different from length LB1 (see FIG. 7). In the front-rear direction (X-axis direction), the length LB4 (see FIG. 8) of the side resin member 10B from the side surface S30 of the laminate sheet 30 is preferably less than 1 mm from the viewpoint of efficiently connecting the laminate-type batteries 1B together. The length LB4 may be the same as or different from the length LB2 (see FIG. 7).

[0094] The side resin member 10B is made of a tab film 50A.

[0095] (2.1.2) Tab Film The tab film 50A has a function of electrically insulating the laminate sheet 30 and the terminals 20, a function of joining the laminate sheet 30 and the terminals 20, and a function as the side surface resin member 10B.

[0096] As shown in Figures 7 and 8, the tab film 50A has an inner excess resin portion 51. The inner excess resin portion 51 protrudes from the entire periphery of the end E20 of the terminal 20 on the electrode body 40 side toward the electrode body 40. The inner excess resin portion 51 is formed, for example, by extruding a molten material of the tab film 50A from the end E20 of the terminal 20 on the electrode body 40 side when the terminal 20 and the laminate sheet 30 are welded by thermocompression bonding. The inner excess resin portion 51 may be welded to the laminate sheet 30 (specifically, the first resin layer 32).

[0097] The tab film 50A is made of a third thermoplastic resin composition. The third thermoplastic resin composition includes a third thermoplastic resin. The third thermoplastic resin is not particularly limited and may be the same as the first thermoplastic resin. In particular, the third thermoplastic resin preferably includes a resin compatible with the first thermoplastic resin. This facilitates welding between the tab film 50A and the first resin layer 32. "Compatible" means that the first thermoplastic resin and the third thermoplastic resin are mixed without separating in an atmosphere in which they melt. The resin compatible with the first thermoplastic resin is appropriately selected depending on the type of first thermoplastic resin. In particular, the third thermoplastic resin preferably includes acid-modified polypropylene to improve adhesion to the terminal 20. When the third thermoplastic resin includes acid-modified polypropylene, the first thermoplastic resin preferably includes unmodified polypropylene. Acid-modified polypropylene has excellent metal adhesion, while unmodified polypropylene has poor metal adhesion. Therefore, when the third thermoplastic resin contains acid-modified polypropylene and the first thermoplastic resin contains unmodified polypropylene, the tab film 50A and the first resin layer 32 are welded together, while welding between the first resin layer 32 and the electrode body 40 is prevented. The third thermoplastic resin composition may contain additives as needed. The additives are the same as those exemplified as the additives for the first thermoplastic resin composition.

[0098] (2.1.3) Action and effect As described with reference to Figures 6 to 8, the laminated battery 1B includes an electrode assembly 40, a pair of terminals 20, a laminate sheet 30, and a side surface resin member 10B. The pair of terminals 20 and the laminate sheet 30 are welded together. The side surface resin member 10B covers the metal layer 31 on the side surface S30 of the laminate sheet 30. As a result, the laminated battery 1B, like the laminated battery 1A, can achieve improved structural efficiency compared to conventional laminated batteries.

[0099] As described with reference to FIGS. 6 to 8, in the laminated battery 1B, a pair of terminals 20 and a laminated sheet 30 are welded together via a tab film 50A. This allows the laminated battery 1B to be produced with excellent productivity.

[0100] As described with reference to FIGS. 6 to 8, in the laminated battery 1B, the side resin member 10B includes a tab film 50A. As a result, in the laminated battery 1B, electrical insulation between the pair of terminals 20 and the metal layer 31 on the side surface S30 of the laminated sheet 30 is ensured by the tab film 50A.

[0101] As described with reference to FIGS. 6 to 8, in the laminated battery 1B, the tab film 50A has an inner excess resin portion 51 that protrudes from the end E20 of the pair of terminals 20 on the electrode body 40 side. In other words, the laminated battery 1B has a space on the side of the inner excess resin portion 51 opposite the laminate sheet 30 side in the thickness direction (Z-axis direction or Y-axis direction) of the tab film 50A. This makes the inner excess resin portion 51 more likely to expand in volume on the side opposite the laminate sheet 30 side when the laminated battery 1B is exposed to high temperatures. In other words, the stress that the laminate sheet 30 receives due to the volume expansion of the inner excess resin portion 51 is less severe than in conventional batteries. As a result, the laminated battery 1B has excellent structural reliability of the laminate sheet 30 even when exposed to high-temperature environments.

[0102] (2.2) Manufacturing method of laminated battery The method for manufacturing a laminated battery according to a second embodiment of the present disclosure is a method for manufacturing a laminated battery 1B. The method for manufacturing a laminated battery according to the second embodiment is similar to the method for manufacturing a laminated battery according to the first embodiment, except that it includes an arrangement step and a deformation step instead of a formation step. The method for manufacturing a laminated battery according to the second embodiment includes a preparation step, an arrangement step, a covering step, a fixing step, a welding step, and a deformation step. In the second embodiment, the preparation step, arrangement step, covering step, fixing step, welding step, and deformation step are performed in this order.

[0103] (2.2.1) Preparation process In the preparation step, a structure and one laminate sheet 30 are prepared. The structure includes an electrode assembly 40 and a pair of terminals 20 electrically connected to the electrode assembly 40. The structure and the laminate sheet 30 may be prepared by any known method.

[0104] (2.2.2) Placement process In the arrangement step, the tab film 50A is arranged on the pair of terminals 20 so that the tab film 50A has a protruding portion 52 protruding from the side surface S30 of the laminate sheet 30. This results in a structure with the tab film. The method for arranging the tab film 50A may be any known method.

[0105] (2.2.3) Coating process In the covering step, the laminate sheet 30 is folded to cover the electrode assembly 40 included in the structure with the tab film with one laminate sheet 30. The method for covering the electrode assembly 40 with the laminate sheet 30 is not particularly limited, and may be, for example, a method in which folds are formed in the laminate sheet 30 by a known method to match the shape of the electrode assembly 40, and the laminate sheet 30 is folded along the folds.

[0106] (2.2.4) Fixing process In the fixing step, the area where the ends of the folded laminate sheet 30 overlap (hereinafter also referred to as the "overlapping area") is thermocompression-bonded to fix the shape of the laminate sheet 30 in a state where it covers the electrode body 40. The method for thermocompression-bonding the overlapping area may be any known method, and examples thereof include a method using a heat bar.

[0107] (2.2.5) Welding process In the welding step, a heat bar is used to weld the terminal 20 to the laminate sheet 30. The heating conditions of the heat bar (for example, heating temperature, heating time, pressure, etc.) are appropriately selected depending on the material of the laminate sheet 30, etc.

[0108] (2.2.6) Deformation process In the deformation process, residual heat of the tab film 50A generated when welding the pair of terminals 20 to the laminate sheet 30 (i.e., heat remaining in the tab film 50A after the welding process) is utilized to deform the protruding portion 52 of the tab film 50A to form the side resin member 10B, thereby obtaining a laminate-type battery 1B.

[0109] The method for deforming the protruding portion 52 of the tab film 50A is not particularly limited, and examples include a method using a jig 70. FIG. 9 shows an example of a method using the jig 70. In the method using the jig 70 shown in FIG. 9, the protruding portion 52 of the tab film 50A is pressed forward in the direction D (positive direction of the X-axis) using the jig 70 while the temperature of the tab film 50A is equal to or higher than the glass transition temperature of the third thermoplastic resin. This allows the protruding portion 52 of the tab film 50A to be deformed so that the protruding portion 52 covers the metal layer 31 on the side surface S30 of the laminate sheet 30. The shape of the side surface resin member 10B can be adjusted by adjusting the shape of the contact surface 70A of the jig 70 with the protruding portion 52.

[0110] (2.2.7) Action and effect As described with reference to FIG. 9, the method for manufacturing the laminated battery of the second embodiment includes an arrangement step and a deformation step. As a result, the laminated battery manufacturing method of the second embodiment can efficiently manufacture the laminated battery 1B.

[0111] (3) Third embodiment (3.1) Laminated battery The laminated battery 1C of the third embodiment of the present disclosure is similar to the laminated battery 1B of the second embodiment, mainly except that the resin film and the side resin member are different members. As shown in Fig. 10, the laminated battery 1C includes a side surface resin member 10C, a pair of terminals 20, a laminate sheet 30, an electrode assembly 40, and a resin film 50B (hereinafter also referred to as "tab film 50B"). The side surface resin member 10C does not include the tab film 50B. The side surface resin member 10C covers the entire side surface S30 of the laminate sheet 30. Each of the pair of terminals 20 and the laminate sheet 30 are directly welded via the tab film 50B.

[0112] As shown in FIGS. 11 and 12, the side surface S30 of the laminate sheet 30 and the outer surface SB20 of the terminal 20 are arranged so as to be flush with each other.

[0113] (3.1.1) Side resin parts 11 and 12, the side surface resin member 10C electrically insulates the terminal 20 from the metal layer 31 on the side surface S30 of the laminate sheet 30. The side surface resin member 10C covers the metal layer 31 on the side surface S30 of the laminate sheet 30. The side surface resin member 10C is welded to each of the first resin layer 32 and the second resin layer 33 on the side surface S30 of the laminate sheet 30.

[0114] As shown in FIG. 11, in a cross section of a laminated battery 1C cut along the front-rear direction (X-axis direction) perpendicular to the front surface SA40 of the electrode body 40, the side resin member 10C preferably has the following dimensions: In the vertical direction (Z-axis direction), the length LC1 (see Figure 11) of the portion of the side resin member 10C protruding from the end EA33 of the second resin layer 33 opposite the electrode body 40 is preferably less than 0.1 mm, and more preferably 0 mm. In the vertical direction (Z-axis direction), the length LC2 (see FIG. 11) of the portion of the side surface resin member 10A that protrudes from the end EA32 of the first resin layer 32 on the electrode body 40 side is preferably equal to or greater than the thickness L6 (see FIG. 11) of the tab film 50B, from the viewpoint of preventing the tab film 50B from protruding from the outer surface S20 of the terminal 20. Preventing the tab film 50B from protruding from the outer surface S20 of the terminal 20 can prevent problems from occurring in other processes (for example, the portion of the tab film 50B protruding from the outer surface S20 of the terminal 20 interfering with the electrical connection between laminate-type batteries 1C). In the front-rear direction (X-axis direction), the length LC3 (see FIG. 11) of the side resin member 10C from the side surface S30 of the laminate sheet 30 is preferably less than 1 mm from the standpoint of efficiently connecting the laminated batteries 1C to each other.

[0115] As shown in FIG. 12, in a cross section of a laminated battery 1C cut along the front-rear direction (X-axis direction) perpendicular to the front surface SA40 of the electrode body 40, the side resin member 10C preferably has the following dimensions: In the left-right direction (Y-axis direction), the length LC3 (see FIG. 12) of the portion of the side surface resin member 10C that protrudes from the end EB33 of the second resin layer 33 opposite to the electrode body 40 is preferably less than 0.1 mm, more preferably 0 mm. The length LC3 may be the same as or different from the length LC1 (see FIG. 11). In the vertical direction (Z-axis direction), the length LC4 (see FIG. 12) of the portion of the side surface resin member 10A protruding from the end EA32 of the first resin layer 32 on the electrode body 40 side is preferably equal to or greater than the thickness L6 (see FIG. 12) of the tab film 50B, from the viewpoint of preventing the tab film 50B from protruding from the outer surface S20 of the terminal 20. The length LC5 may be the same as or different from the length LC2 (see FIG. 11). In the front-rear direction (X-axis direction), the length LC6 (see FIG. 11) of the side resin member 10C from the side surface S30 of the laminate sheet 30 is preferably less than 1 mm from the viewpoint of efficiently connecting the laminate-type batteries 1C to each other. The length LC6 may be the same as or different from the length LC3 (see FIG. 11).

[0116] The material of the side surface resin member 10C is the same as the example material of the side surface resin member 10A.

[0117] (3.1.2) Tab Film The tab film 50B has a function of electrically insulating the laminate sheet 30 and the terminal 20 and a function of joining the laminate sheet 30 and the terminal 20 together. The tab film 50B is similar to the tab film 50A in the second embodiment, except that it does not function as a side resin member.

[0118] (3.1.3) Action and effect 10 to 12, the laminated battery 1C includes an electrode assembly 40, a pair of terminals 20, a laminated sheet 30, and a side surface resin member 10C. The pair of terminals 20 and the laminated sheet 30 are welded together. The side surface resin member 10C covers the metal layer 31 on the side surface S30 of the laminated sheet 30. As a result, the laminated battery 1C, like the laminated battery 1A, can achieve improved structural efficiency compared to conventional laminated batteries.

[0119] As described with reference to FIGS. 10 to 12, in the laminated battery 1C, a pair of terminals 20 and a laminated sheet 30 are welded together via a tab film 50B. This makes the laminated battery 1C highly productive.

[0120] As described with reference to FIGS. 10 to 12, in the laminated battery 1C, the side resin member 10C does not include the tab film 50B. As a result, in the laminated battery 1C, electrical insulation between the pair of terminals 20 and the metal layer 31 on the side surface S30 of the laminated sheet 30 is ensured by the side surface resin member 10C.

[0121] As described with reference to FIGS. 10 to 12, in the laminated battery 1C, the tab film 50B has an inner excess resin portion 51 that protrudes from the end E20 of the pair of terminals 20 on the electrode body 40 side. As a result, the laminated battery 1C, like the laminated battery 1B, has excellent structural reliability of the laminated sheet 30 even when exposed to a high-temperature environment.

[0122] (3.2) Manufacturing method of laminated battery The manufacturing method for a laminated battery according to a third embodiment of the present disclosure is a method for manufacturing a laminated battery 1C. The manufacturing method for a laminated battery according to the third embodiment is similar to the manufacturing method for a laminated battery according to the first embodiment, except that it further includes an arrangement step. The manufacturing method for a laminated battery according to the third embodiment includes a preparation step, an arrangement step, a covering step, a fixing step, a forming step, and a welding step. In the third embodiment, the preparation step, arrangement step, covering step, fixing step, formation step, and welding step are performed in this order.

[0123] (3.2.1) Preparation process In the preparation step, a structure and one laminate sheet 30 are prepared. The structure includes an electrode assembly 40 and a pair of terminals 20 electrically connected to the electrode assembly 40. The structure and the laminate sheet 30 may be prepared by any known method.

[0124] (3.2.2) Placement process In the disposing step, the tab film 50B is disposed on the pair of terminals 20. This provides a structure with the tab film 50B. The method for disposing the tab film 50B may be any known method.

[0125] (3.2.3) Coating process In the covering step, the laminate sheet 30 is folded to cover the electrode assembly 40 included in the structure with the tab film with one laminate sheet 30. The method for covering the electrode assembly 40 with the laminate sheet 30 is not particularly limited, and may be, for example, a method in which folds are formed in the laminate sheet 30 by a known method to match the shape of the electrode assembly 40, and the laminate sheet 30 is folded along the folds.

[0126] (3.2.4) Fixing process In the fixing step, the area where the ends of the folded laminate sheet 30 overlap (hereinafter also referred to as the "overlapping area") is thermocompression-bonded to fix the shape of the laminate sheet 30 in a state where it covers the electrode body 40. The method for thermocompression-bonding the overlapping area may be any known method, and examples thereof include a method using a heat bar.

[0127] (3.2.5) Formation process In the forming step, the side surface resin member 10C is formed on the side surface S30 of the laminate sheet 30. The method for forming the side surface resin member 10A is the same as the method exemplified as the forming method in the forming step of the first embodiment.

[0128] In this case, it is preferable that the length LC2 (see FIG. 11) and the length LC4 (see FIG. 12) of the side surface resin member 10C are each equal to or greater than the thickness L6 (see FIGS. 11 and 12) of the tab film 50B. As a result, in the welding process, the side surface resin member 10C functions as a wall that prevents the molten material of the tab film 50B from being extruded onto the side surface S30 of the laminate sheet 30. In this way, by adjusting the length LC2 (see FIG. 11) and the length LC4 (see FIG. 12) of the side surface resin member 10C, it is possible to adjust the amount of the molten material of the tab film 50B that protrudes from the outer surface S20 of the terminal 20. As a result, the tab film 50B is prevented from protruding from the outer surface S20 of the terminal 20.

[0129] (3.2.6) Welding process In the welding step, a heat bar is used to weld the terminal 20 to the laminate sheet 30. The heating conditions of the heat bar (for example, heating temperature, heating time, pressure, etc.) are appropriately selected depending on the material of the laminate sheet 30, etc.

[0130] (3.2.7) Action and effect As described above, the method for manufacturing the laminated battery of the third embodiment includes the arranging step and the forming step. As a result, the laminated battery manufacturing method of the third embodiment can efficiently manufacture the laminated battery 1C.

[0131] (4) Fourth embodiment A battery stack 2B according to the fourth embodiment of the present disclosure is similar to the battery stack 2A according to the first embodiment, except that the shape of the inter-battery connection terminals is different. 13, the battery stack 2B includes multiple laminated batteries 1A and multiple inter-battery connection terminals 60B. The multiple inter-battery connection terminals 60B are electrically connected to terminals 20, connecting the multiple laminated batteries 1A in series.

[0132] The inter-battery connection terminals 60B are components (bus bars) for electrically connecting the multiple laminated batteries 1A in series. The inter-battery connection terminal 60B has a first terminal component 61 and a second terminal component 62. The first terminal component 61 is an L-shaped bent plate-like member. The first terminal component 61 is electrically connected to one of a pair of terminals 20 included in a laminated battery 1A. Hereinafter, a laminated battery 1A electrically connected to the first terminal component 61 will be referred to as a "battery with first terminal component." The second terminal component 62 is an L-shaped bent plate-like member. The second terminal component 62 is electrically connected to one of a pair of terminals 20 included in a laminated battery 1A adjacent to the battery with the first terminal component, among multiple laminated batteries 1A. Hereinafter, a laminated battery 1A electrically connected to the second terminal component 62 will be referred to as a "battery with second terminal component." The first terminal component 61 and the second terminal component 62 are electrically connected. The first terminal component 61 is attached to the outer surface SB20 of the terminal 20 of the battery with the first terminal component. The second terminal component 62 is attached to the outer surface SB20 of the terminal 20 of the battery with the second terminal component. The first terminal component 61 is attached to the second terminal component 62. The method of attaching the first terminal component 61 and the second terminal component 62 is not particularly limited, and may be the same as the method exemplified as the method of attaching the inter-battery connection terminal 60A of the first embodiment.

[0133] 13, the battery stack 2B includes multiple laminated batteries 1A and multiple inter-battery connection terminals 60B. Each inter-battery connection terminal 60B has a first terminal component 61 and a second terminal component 62. This allows for better productivity of the battery stack 2B than when the inter-battery connection terminal 60B does not have the first terminal part 61 and the second terminal part 62.

[0134] (5) Variations In the first to fourth embodiments, the electrode assembly 40 has a plurality of unit electrode bodies 41, but may have a single unit electrode body 41. In the first to fourth embodiments, the unit electrode body 41 has a solid electrolyte layer, but a non-aqueous electrolyte solution may be used instead of the solid electrolyte layer.

[0135] In the first to fourth embodiments, the side surface members are terminals, but they do not have to be terminals. For example, the side surface members may be metal lids that do not function as terminals. The metal lids may have through holes for electrically connecting the terminals of the laminated battery to inter-battery connection terminals outside the laminated battery.

[0136] In the first to fourth embodiments, the opposing surfaces of the terminals are electrically connected to the electrode body, but the opposing surfaces of the terminals do not have to be electrically connected to the electrode body.

[0137] In the first to fourth embodiments, the pair of terminals face each other across the electrode body, but they do not have to face each other across the electrode body.

[0138] In the first to fourth embodiments, the laminated battery is a laminated lithium secondary battery using a solid electrolyte, but it may also be a secondary battery such as a nickel-metal hydride battery.

[0139] In the first to fourth embodiments, the terminals have a rectangular parallelepiped shape, but they do not have to have a rectangular parallelepiped shape.

[0140] In the first to fourth embodiments, the length L4 (see FIG. 2) is longer than the length L1 (see FIG. 2), but it may be the same as or shorter than the length L1.

[0141] In the second and third embodiments, the tab film 50A or the tab film 50B has the inner excess resin portion 51, but the inner excess resin portion 51 may not be included.

[0142] In the first embodiment, the battery connection terminal is a single plate-like member, but the shape of the battery connection terminal is not limited as long as it connects multiple laminated batteries 1A in series. In the fourth embodiment, the first and second terminal components are each L-shaped plate-like members, but the shapes of the first and second terminal components are not particularly limited as long as they connect multiple laminated batteries 1A in series and electrically connect the first and second terminal components. [Explanation of symbols]

[0143] 1A, 1B, 1C laminated battery 2A, 2B battery stack 10A, 10B, 10C Side resin parts 20 terminals 30 Laminate Sheet 40 Electrode body 50A, 50B tab film

Claims

1. A laminated battery, An electrode body; a side surface member disposed on a side surface of the electrode body; a laminate sheet covering the electrode body; a side resin member attached to a side surface of the laminate sheet on the side surface member side; Equipped with the side member and the laminate sheet are welded together, the laminate sheet has a metal layer, A laminated battery, wherein the side resin member covers the metal layer on the side of the laminate sheet.

2. 2. The laminated battery according to claim 1, wherein the side member and the laminate sheet are directly welded together.

3. Further provided is a resin film disposed between the side member and the laminate sheet, The laminated battery according to claim 1 , wherein the side surface member and the laminate sheet are welded together via the resin film.

4. The laminated battery according to claim 3 , wherein the side resin member includes the resin film.

5. The laminated battery according to claim 3 , wherein the side resin member does not include the resin film.

6. The laminated battery according to claim 3 , wherein the resin film has an inner excess resin portion that protrudes from an end of the side member on the electrode body side.

7. the electrode assembly includes at least one unit electrode assembly, 2. The laminated battery according to claim 1, wherein the unit electrode body is formed by laminating a positive electrode current collector, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector in this order.

8. the side member is a terminal, the terminal has an opposing surface facing the side surface of the electrode body, 8. The laminated battery according to claim 1, wherein the opposing surface is electrically connected to the electrode body.

9. The laminated battery according to claim 8 , comprising a pair of the terminals facing each other with the electrode body interposed therebetween.

10. a plurality of laminated batteries according to claim 9 stacked in a direction parallel to the side surfaces of the electrode bodies; a plurality of inter-battery connection terminals electrically connected to the terminals and connecting a plurality of the laminated batteries in series.

11. A method for manufacturing a laminated battery, comprising: The laminated battery comprises: An electrode body; a side surface member disposed on a side surface of the electrode body; a laminate sheet covering the electrode body; a side resin member attached to a side surface of the laminate sheet on the side surface member side; Equipped with the side member and the laminate sheet are directly welded together, the laminate sheet has a metal layer, forming the side surface resin member on the side surface of the laminate sheet to cover the metal layer on the side surface of the laminate sheet; welding the side member and the laminate sheet together with a heat bar; A method for manufacturing a laminated battery, comprising:

12. A method for manufacturing a laminated battery, comprising: The laminated battery comprises: An electrode body; a side surface member disposed on a side surface of the electrode body; a laminate sheet covering the electrode body; a side resin member attached to a side surface of the laminate sheet on the side surface member side; Equipped with the side surface resin member includes a resin film disposed between the side surface member and the laminate sheet, the side surface member and the laminate sheet are welded together via the resin film, the laminate sheet has a metal layer, the side surface resin member covers the metal layer on the side surface of the laminate sheet, disposing a resin film on the side member so that the resin film has a protruding portion protruding from the side surface of the laminate sheet; welding the side surface member and the laminate sheet together with the resin film interposed therebetween using a heat bar; deforming the protruding portion by utilizing residual heat of the resin film when the side surface member and the laminate sheet are welded together, thereby forming the side surface resin member; A method for manufacturing a laminated battery, comprising:

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