Battery

Abstract

To provide a battery that can restrain moisture intrusion.SOLUTION: In a battery including an electrode body, a current collector terminal disposed at a side surface portion of the electrode body, and a laminate film covering the electrode body and the current collector terminal, the current collector terminal has a first surface facing the electrode body, a second surface facing the first surface, a third surface extending from the outer edge of the first surface to the second surface side, and a first connecting surface connecting the third surface and the second surface. When the battery is viewed in cross section in a thickness direction thereof, and the boundary between the third surface and the first connecting surface is represented by B1 and the boundary between the first connecting surface and the second surface is represented by B2, the B2 is located inside the B1 in the thickness direction, and the laminate film covers the third surface and the first connecting surface.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to batteries. [Background technology]

[0002] Batteries such as lithium-ion secondary batteries typically include an electrode assembly having a positive electrode current collector, a positive electrode active material layer, an electrolyte layer, a negative electrode active material layer, and a negative electrode current collector. The electrode assembly is sealed in an internal space surrounded by, for example, an exterior material. Patent Document 1 discloses a lithium polymer secondary battery that includes an electrode assembly, an exterior material surrounding the exterior of the electrode assembly, and first and second covers that seal the exterior material, with a first electrode terminal and a second electrode terminal extending to the outside via the first cover and the second cover, respectively. Patent Document 1 also describes a laminate film as the exterior material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-108623 Summary of the Invention [Problem to be solved by the invention]

[0004] A laminate film typically has a metal layer and a resin layer. The metal layer is not permeable to moisture, but the resin layer is. If moisture penetrates through the resin layer into the internal space sealed by the laminate film, deterioration of the electrode assembly occurs.

[0005] The present disclosure has been made in view of the above circumstances, and has as its main object to provide a battery capable of suppressing the intrusion of moisture. [Means for solving the problem]

[0006] [1] A battery comprising an electrode body, a current collecting terminal arranged on a side portion of the electrode body, and a laminate film covering the electrode body and the current collecting terminal, wherein the current collecting terminal has a first surface facing the electrode body, a second surface facing the first surface, a third surface extending from an outer edge of the first surface toward the second surface, and a first connecting surface connecting the third surface and the second surface, wherein when the battery is viewed in cross section in the thickness direction, the boundary between the third surface and the first connecting surface is defined as B1 and the boundary between the first connecting surface and the second surface is defined as B2, B2 is located inside B1 in the thickness direction, and the laminate film covers the third surface and the first connecting surface.

[0007] [2] The battery according to [1], wherein, when the battery is viewed in cross section in the thickness direction, B1 and B2 are connected by one straight line, multiple straight lines, or a curved line.

[0008] [3] The battery according to [1] or [2], wherein the current collecting terminal extends from the outer edge of the first surface toward the second surface and has a fourth surface opposite the third surface, and a second connecting surface connecting the fourth surface and the second surface, and when the battery is viewed in cross section in the thickness direction, the boundary between the fourth surface and the second connecting surface is defined as B3 and the boundary between the second connecting surface and the second surface is defined as B4, B4 is located inside B3 in the thickness direction, and the laminate film covers the fourth surface and the second connecting surface.

[0009] [4] The battery according to [3], wherein, when the battery is viewed in cross section in the thickness direction, B3 and B4 are connected by one straight line, multiple straight lines, or a curved line.

[0010] [5] The battery according to any one of [1] to [4], wherein a resin film is disposed between the current collecting terminal and the laminate film, and an end of the resin film protrudes beyond an end of the laminate film.

[0011] [6] A battery comprising an electrode body, a current collecting terminal arranged on a side portion of the electrode body, and a laminate film covering the electrode body and the current collecting terminal, wherein the current collecting terminal has a first surface facing the electrode body, a second surface facing the first surface, and a third surface extending from an outer edge of the first surface toward the second surface, a first groove arranged on the third surface, and the laminate film covering the first groove on the third surface.

[0012] [7] A battery comprising an electrode body, a current collecting terminal arranged on a side portion of the electrode body, and a laminate film covering the electrode body and the current collecting terminal, wherein the current collecting terminal has a first surface facing the electrode body, a second surface facing the first surface, and a third surface extending from the outer edge of the first surface toward the second surface, and the laminate film extends to the second surface while covering the third surface, and a portion of the second surface is not covered by the laminate film. [Effects of the Invention]

[0013] The present disclosure has an effect of providing a battery capable of suppressing the intrusion of moisture. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic perspective view illustrating an electrode assembly according to the present disclosure. [Figure 2] FIG. 1 is a schematic perspective view illustrating a battery according to the present disclosure. [Figure 3] FIG. 1 is a schematic cross-sectional view illustrating a battery according to the present disclosure. [Figure 4] FIG. 1 is an explanatory diagram illustrating a problem in the present disclosure. [Figure 5] FIG. 1 is a schematic cross-sectional view illustrating a battery according to the present disclosure. [Figure 6] FIG. 2 is a schematic perspective view illustrating a current collecting terminal according to the present disclosure. [Figure 7] FIG. 2 is a schematic side view illustrating an electrode body and a current collecting terminal according to the present disclosure. [Figure 8] 1 is a schematic cross-sectional view illustrating a current collecting tab and a current collecting terminal according to the present disclosure. [Figure 9] 1 is a schematic cross-sectional view illustrating an electrode body according to the present disclosure. [Figure 10] FIG. 2 is a schematic cross-sectional view illustrating a current collecting terminal according to the present disclosure. [Figure 11] FIG. 2 is a schematic cross-sectional view illustrating a current collecting terminal according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] The battery of the present disclosure will be described in detail below with reference to the drawings. The following drawings are schematic illustrations, and the size and shape of each part are appropriately exaggerated for ease of understanding. Furthermore, in this specification, when describing an arrangement of another member relative to a certain member, the term "above" or "below" refers to both an arrangement of another member directly above or below the certain member, in contact with the certain member, and an arrangement of another member above or below the certain member via another member, unless otherwise specified.

[0016] Fig. 1 is a schematic perspective view illustrating an electrode assembly according to the present disclosure, and Fig. 2 is a schematic perspective view illustrating a battery according to the present disclosure. The electrode assembly 10 shown in Fig. 1 has a top surface portion 11, a bottom surface portion 12 facing the top surface portion 11, and four side surfaces (a first side surface portion 13, a second side surface portion 14, a third side surface portion 15, and a fourth side surface portion 16) connecting the top surface portion 11 and the bottom surface portion 12. As shown in Figs. 2(a) and 2(b), the battery 100 has the electrode assembly 10, current collector terminals 20 (positive electrode current collector terminal 20A, negative electrode current collector terminal 20B) arranged on the side surfaces (the first side surface portion 13 and the third side surface portion 15) of the electrode assembly 10, and a laminate film 30 covering the electrode assembly 10 and the current collector terminals 20. 1 and 2, the Z direction corresponds to the thickness direction of the battery, the X direction corresponds to the width direction of the battery, and the Y direction corresponds to the depth direction of the battery.

[0017] FIG. 3(a) is a schematic cross-sectional view illustrating a battery according to the present disclosure, and FIG. 3(b) is an enlarged view of a portion of FIG. 3(a). As shown in FIGS. 3(a) and 3(b), the current collecting terminal 20 has a first surface S1 facing the electrode assembly 10, a second surface S2 facing the first surface S1, a third surface S3 extending from the outer edge of the first surface S1 toward the second surface S2, and a first connecting surface SL1 connecting the third surface S3 and the second surface S2. The electrode assembly 10 also has a current collecting tab T, and the current collecting tab T and the current collecting terminal 20 are electrically connected. More specifically, the current collecting tab T is joined to the first surface S1 of the electrode assembly 10, thereby electrically connecting the current collecting tab T and the current collecting terminal 20. The boundary between the third surface S3 and the first connecting surface SL1 is designated B1, and the boundary between the first connecting surface SL1 and the second surface S2 is designated B2. B2 is located inside B1 in the thickness direction (Z direction). That is, B1 protrudes from B2 in the thickness direction (Z direction). In other words, a structure (cutout structure) is formed in which a corner formed by an extension line of the second surface S2 and an extension line of the third surface S3 is cut by the first connecting surface SL1. In addition, in Figures 3(a) and (b), the laminate film 30 covers the third surface S3 and the first connecting surface SL1. In addition, a resin film 40 is disposed between the current collecting terminal 20 and the laminate film 30 to improve adhesion between them.

[0018] According to the present disclosure, a battery can be formed that can suppress moisture penetration by having a current collecting terminal with a first connecting surface and a laminate film disposed to cover the first connecting surface. Here, as shown in FIG. 4(a), a case is assumed in which the current collecting terminal 20 does not have a first connecting surface. FIG. 4(b) is an enlarged view of region α in FIG. 4(a). The laminate film 30 shown in FIG. 4(b) includes a metal layer 31, an inner resin layer 32 disposed on the current collecting terminal 20 side of the metal layer 31, and an outer resin layer 33 disposed on the surface of the metal layer 31 opposite the inner resin layer 32. The metal layer 31 is not permeable to moisture. Therefore, moisture does not generally penetrate from the thickness direction Z of the battery. On the other hand, the inner resin layer 32 and the resin film 40 in the laminate film 30 are permeable to moisture. Therefore, moisture can penetrate from the depth direction Y of the battery. The penetration of moisture in the depth direction Y depends greatly on the cross-sectional area of ​​the resin layer in the depth direction Y and the length of the penetration path. In particular, with regard to the latter, the longer the penetration path, the more moisture penetration is suppressed. Comparing FIG. 3(a) and FIG. 4(a), the current collecting terminal 20 in FIG. 3(a) has the first connecting surface SL1, so the moisture penetration path in FIG. 3(a) is longer than the moisture penetration path in FIG. 4(a). As a result, moisture penetration is suppressed. Furthermore, for example, simply increasing the length of the current collecting terminal 20 in the depth direction Y in FIG. 4(a) achieves the effect of lengthening the penetration path. On the other hand, increasing the size of the current collecting terminal 20 reduces the structural efficiency of the battery (the ratio of the effective reaction area of ​​the battery to the total area of ​​the battery in the thickness direction Z). In contrast, providing the first connecting surface SL1 as shown in FIG. 3(a) allows the moisture penetration path to be expanded in the thickness direction Z, thereby suppressing a decrease in the structural efficiency of the battery.

[0019] 1. Battery configuration The battery according to the present disclosure comprises an electrode body, a current collecting terminal, and a laminate film.

[0020] An electrode body in the present disclosure typically has a top surface portion, a bottom surface portion opposite the top surface portion, and multiple side surfaces connecting the top surface portion and the bottom surface portion. For example, the electrode body 10 shown in Fig. 1 has a top surface portion 11, a bottom surface portion 12 opposite the top surface portion 11, and four side surfaces (a first side surface portion 13, a second side surface portion 14, a third side surface portion 15, and a fourth side surface portion 16) connecting the top surface portion 11 and the bottom surface portion 12. The normal directions of the top surface portion 11 and the bottom surface portion 12 are parallel to the thickness direction Z, and correspond to the main surfaces of the electrode body 10.

[0021] In the present disclosure, the current collecting terminals are disposed on the side surfaces of the electrode assembly. For example, in FIG. 2, a positive electrode current collecting terminal 20A and a negative electrode current collecting terminal 20B are disposed on the first side surface 13 and the third side surface 15 of the electrode assembly 10, respectively. The laminate film in the present disclosure is disposed so as to cover the electrode assembly and the current collecting terminals. The laminate film is preferably a single film. For example, in the case of the electrode assembly 10 shown in FIG. 1, the top surface 11, the fourth side surface 16, the bottom surface 12, and the second side surface 14 are covered by a single laminate film 30. In the case of the current collecting terminal 20 shown in FIGS. 6(a) to 6(d), which will be described later, the third surface S3, the fifth surface S5, the fourth surface S4, and the sixth surface S6 are covered by a single laminate film 30. The laminate film 30 is welded to the current collecting terminal 20.

[0022] As shown in FIG. 3(b), the current collecting terminal 20 has a first surface S1 facing the electrode body (not shown), a second surface S2 facing the first surface S1, a third surface S3 extending from the outer edge of the first surface S1 toward the second surface S2, and a first connecting surface SL1 connecting the third surface S3 and the second surface S2. As shown in FIG. 3(b), the first surface S1, the second surface S2, the third surface S3, and the first connecting surface SL1 may each be represented by a straight line in the YZ plane. As shown in FIG. 3(b), in the YZ plane, the boundary between the first surface S1 and the third surface S3 is denoted by B0, the boundary between the third surface S3 and the first connecting surface SL1 is denoted by B1, and the boundary between the first connecting surface SL1 and the second surface S2 is denoted by B2.

[0023] In FIG. 3(b), B1 is located at the same position as B0 in the thickness direction Z. B2 is located more inward (closer to the fourth surface S4) than B1 in the thickness direction Z. As shown in FIG. 3(b), the distance between B1 and B2 in the thickness direction Z is L1, and the distance between B1 and B2 in the depth direction Y is L2. L1 and L2 are each, for example, 1 mm or more, and may be 3 mm or more. The length of the current collecting terminal 20 in the thickness direction Z is not particularly limited, but is, for example, 5 mm or more and 15 mm or less. The distance between the first surface S1 and the second surface S2 in the depth direction Y is not particularly limited, but is, for example, 5 mm or more and 15 mm or less.

[0024] The laminate film 30 covers the third surface S3 and the first connecting surface SL1. Preferably, the laminate film 30 covers the entire third surface S3. Alternatively, the laminate film 30 may cover at least a portion of the first connecting surface SL1, or may cover the entire first connecting surface SL1. As shown in FIG. 3(b), in the YZ plane, B1 and B2 may be connected by a single straight line. Specifically, in FIG. 3(b), the cross section of the first connecting surface SL1 is formed by the straight line connecting B1 and B2. As shown in FIG. 5(a), in the YZ plane, B1 and B2 may be connected by multiple straight lines. Specifically, in FIG. 5(a), the cross section of the first connecting surface SL1 is formed by the straight line connecting B1 and C and the straight line connecting C and B2. As shown in FIG. 5(b), in the YZ plane, B1 and B2 may be connected by a curved line. Specifically, in FIG. 5(b), the cross section of the first coupling surface SL1 is formed by a curve connecting B1 and B2.

[0025] As shown in FIGS. 3(b), 5(a), and 5(b), the current collecting terminal 20 may have a fourth surface S4 that extends from the outer edge of the first surface S1 toward the second surface S2 and faces the third surface S3. Furthermore, the current collecting terminal 20 may have a second connecting surface SL2 that connects the fourth surface S4 and the second surface S2. As shown in FIG. 3(b), in the YZ plane, the boundary between the fourth surface S4 and the second connecting surface SL2 is designated as B3, and the boundary between the second connecting surface SL2 and the second surface S2 is designated as B4. B4 is located inside B3 (the third surface S3) in the thickness direction Z. Details of the fourth surface S4 and the second connecting surface SL2 are the same as those described above for the third surface S3 and the first connecting surface SL1, respectively.

[0026] As shown in FIG. 3(b), a resin film 40 may be disposed between the current collecting terminal 20 and the laminate film 30. By disposing the resin film 40, the adhesion between the current collecting terminal 20 and the laminate film 30 is improved. Furthermore, by disposing the resin film 40, it is possible to suppress the occurrence of a short circuit, even if, for example, a conductive foreign object is present on the surface of the current collecting terminal 20. On the other hand, by disposing the resin film 40, moisture can easily penetrate. In contrast, in the present disclosure, the first connecting surface SL1 is provided, which lengthens the path for moisture penetration and suppresses moisture penetration. Furthermore, although not particularly shown, there may be no resin film between the current collecting terminal 20 and the laminate film 30, and the current collecting terminal 20 and the laminate film 30 may be in direct contact with each other. Furthermore, as shown in FIG. 3(b), the end t of the resin film 40 40 is the end t of the laminate film 30 30 The end t may protrude further. 40 The end T 30 By making it protrude further, even if the current collecting terminal 20 and the laminate film 30 are misaligned, for example, poor adhesion can be prevented.

[0027] As shown in Figures 6(a) to 6(d), in addition to the first surface S1, second surface S2, third surface S3, and fourth surface S4, the current collecting terminal 20 may have a fifth surface S5 extending from the outer edge of the first surface S1 toward the second surface S2, and a sixth surface S5 extending from the outer edge of the first surface S1 toward the second surface S2 and facing the fifth surface S5. In Figures 6(a) to 6(d), the first connecting surface SL1 and the second connecting surface SL2 each extend in the width direction (X direction) of the battery. Furthermore, as shown in Figures 6(c) and 6(d), the current collecting terminal 20 may have at least one of a third connecting surface SL3 connecting the fifth surface S5 and the second surface S2 and a fourth connecting surface SL4 connecting the sixth surface S6 and the second surface S2. Details of the third connecting surface SL3 and the fourth connecting surface SL4 are the same as those described above for the first connecting surface SL1. When the battery is cross-sectionally viewed in a direction perpendicular to the thickness direction (when the battery is cross-sectionally viewed on the XY plane), the boundary between the fifth surface S5 and the third connecting surface SL3 is defined as B5, and the boundary between the third connecting surface SL3 and the second surface S2 is defined as B6. B6 is preferably located inside B5 in the width direction (X direction) of the battery. The laminate film preferably covers the fifth surface S5 and the third connecting surface SL3. When the battery is cross-sectionally viewed in a direction perpendicular to the thickness direction (when the battery is cross-sectionally viewed on the XY plane), the boundary between the sixth surface S6 and the fourth connecting surface SL4 is defined as B7, and the boundary between the fourth connecting surface SL4 and the second surface S2 is defined as B8. B8 is preferably located inside B7 in the width direction (X direction) of the battery. The laminate film preferably covers the sixth surface S6 and the fourth connecting surface SL4.

[0028] 7 is a schematic side view illustrating an electrode assembly and a current collecting terminal according to the present disclosure. In FIG. 7, the outer edge shape of the electrode assembly 10 and the outer edge shape of the current collecting terminal 20 are rectangular. The length (total perimeter) of the outer edge of the electrode assembly 10 is L. 10 The length of the outer edge of the current collecting terminal 20 (total perimeter length) is L 20 Let's say. L 10 L for 20 The ratio (L 20 / L 10) is, for example, 0.7 or more and 1 or less, and may be 0.8 or more and 0.95 or less. Furthermore, the length of the electrode body 10 in the thickness direction Z is L 10Z The length of the current collecting terminal 20 in the thickness direction Z is L 20Z Let's say. L 10Z L for 20Z The ratio (L 20Z / L 10Z ) is, for example, 0.7 or more and 1.0 or less, and may be 0.8 or more and 0.95 or less. 10X The length of the current collecting terminal 20 in the width direction X is L 20X Let's say. L 10X L for 20X The ratio (L 20X / L 10X ) is, for example, 0.7 or more and 1.0 or less, and may be 0.8 or more and 0.95 or less.

[0029] As shown in FIG. 8, the current collecting tab T preferably has a root portion P, which is the end on the electrode body 10 side, a connection portion Q for connection to the current collecting terminal 20, and an intermediate portion R connecting the root portion P and the connection portion Q. The root portion P is the end (boundary portion) of the current collecting tab T on the electrode body 10 side. The connection portion Q is a portion for connection to the current collecting terminal 20 and is a portion that constitutes a stacked connection portion W, which will be described later. The intermediate portion R is a portion that connects the root portion P and the connection portion Q. In the present disclosure, it is preferable that the connection portions of the multiple current collecting tabs have a stacked connection portion in which each connection portion is stacked in the thickness direction. In FIG. 8, the connection portions Q of the multiple current collecting tabs T are stacked in the thickness direction of the current collecting tab T, thereby forming the stacked connection portion W. In the stacked connection portion W, the connection portions Y are joined to each other (fixed to each other).

[0030] As shown in FIG. 8, in a cross-sectional view of the electrode body 10 in the stacking direction (thickness direction Z of the battery), the intermediate portions R preferably have a curved structure in which parts of the intermediate portions R are curved so as to face each other. In the present disclosure, it is preferable that the intermediate portion R of at least one of the multiple current collecting tabs T has a curved structure. In the curved structure, parts of the opposing intermediate portions Z may be arranged so as to be in direct contact with each other, or may be arranged with a space between them. Furthermore, as shown in FIG. 8, it is preferable that the intermediate portions R of the multiple current collecting tabs T are curved in a U-shape.

[0031] 2. Battery components The battery according to the present disclosure comprises an electrode body, a current collecting terminal, and a laminate film.

[0032] (1) Electrode body Fig. 9 is a schematic cross-sectional view illustrating an electrode assembly according to the present disclosure. The electrode assembly 10 in Fig. 9 includes a positive electrode active material layer 1, a negative electrode active material layer 2, an electrolyte layer 3 disposed on the positive electrode active material layer 1 and the negative electrode active material layer 2, a positive electrode current collector 4 that collects current from the positive electrode active material layer 1, and a negative electrode current collector 5 that collects current from the negative electrode active material layer 2. The electrode assembly 10 also includes a positive electrode tab 4t formed continuously from the positive electrode current collector 4 and a negative electrode tab 5t formed continuously from the negative electrode current collector 5. When the positive electrode active material layer, the electrolyte layer, and the negative electrode active material layer are considered to be power generation units, the electrode assembly according to the present disclosure may include one power generation unit or two or more power generation units.

[0033] The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the positive electrode active material include oxide active materials. Examples of the oxide active material include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Examples of the positive electrode active material include rock salt layer-type active materials such as O2, spinel-type active materials such as LiMn2O4, and olivine-type active materials such as LiFePO4. Sulfur (S) may also be used as the positive electrode active material. The positive electrode active material may be, for example, in the form of particles.

[0034] Examples of conductive materials include carbon materials. The electrolyte may be a solid electrolyte or a liquid electrolyte. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. The liquid electrolyte (electrolytic solution) contains, for example, a supporting salt such as LiPF6 and a solvent such as a carbonate-based solvent. Examples of binders include rubber-based binders and fluoride-based binders.

[0035] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may further contain at least one of a conductive material, an electrolyte, and a binder. Examples of the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, and Li4Ti5O 12 The negative electrode active material may be in the form of particles or foil, for example. The conductive material, electrolyte, and binder are the same as those described above.

[0036] The electrolyte layer is disposed between the positive electrode active material layer and the negative electrode active material layer and contains at least an electrolyte. The electrolyte may be a solid electrolyte or a liquid electrolyte. The electrolyte is the same as described above. The electrolyte layer may have a separator.

[0037] The positive electrode current collector collects current from the positive electrode active material layer. Examples of the material for the positive electrode current collector include metals such as aluminum, SUS, and nickel. Examples of the shape of the positive electrode current collector include foil and mesh. The negative electrode current collector collects current from the negative electrode active material layer. Examples of the material for the negative electrode current collector include metals such as copper, SUS, and nickel. Examples of the shape of the negative electrode current collector include foil and mesh.

[0038] (2) Current collector terminal The current collecting terminal in the present disclosure is disposed on the side surface of the electrode body. The current collecting terminal refers to a terminal having a current collecting portion at least in part. The current collecting portion is electrically connected to, for example, a current collecting tab in the electrode body. The current collecting terminal may be entirely or partially a current collecting portion. Examples of materials for the current collecting terminal include metals such as aluminum and SUS.

[0039] (3) Laminate film The laminate film of the present disclosure typically has a metal layer and an inner resin layer. The inner resin layer is welded to a current collecting terminal. The laminate film may also have an outer resin layer on the opposite side of the metal layer from the inner resin layer. Examples of materials for the metal layer include metals such as aluminum and SUS. Examples of materials for the inner resin layer include olefin-based resins such as polypropylene (PP) and polyethylene (PE). Examples of materials for the outer resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. The thickness of the inner resin layer is, for example, 40 μm or more and 100 μm or less. The thickness of the outer resin layer is, for example, 20 μm or more and 60 μm or less. The overall thickness of the laminate film is, for example, 80 μm or more and 250 μm or less.

[0040] A resin film may be disposed between the laminate film and the current collecting terminals. Examples of materials for the resin film include olefin resins such as polypropylene (PP) and polyethylene (PE).

[0041] (4)Battery The battery in the present disclosure is typically a lithium-ion secondary battery. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. It is particularly preferred that the battery be used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery in the present disclosure may also be used as a power source for mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0042] 3. First Modification The present disclosure provides a battery comprising an electrode body, a current collecting terminal arranged on a side portion of the electrode body, and a laminate film covering the electrode body and the current collecting terminal, wherein the current collecting terminal has a first surface facing the electrode body, a second surface facing the first surface, and a third surface extending from the outer edge of the first surface toward the second surface, a first groove arranged on the third surface, and the laminate film covering the first groove on the third surface.

[0043] The current collecting terminal 20 shown in Fig. 10 has a first surface S1 facing the electrode body (not shown), a second surface S2 facing the first surface S1, and a third surface S3 extending from the outer edge of the first surface S1 toward the second surface S2. A first groove G1 is arranged on the third surface S3, with the bottom located at the center of the current collecting terminal 20. A laminate film 30 covers the first groove G1 on the third surface S3. The current collecting terminal 20 has the first groove G1, and the laminate film 30 is arranged to cover the first groove G1, resulting in a battery that can suppress moisture penetration. The first groove preferably extends in the width direction X of the battery (the depth direction of the paper in Fig. 10).

[0044] As shown in FIG. 10, the depth of the first groove G1 is L3. L3 is, for example, 0.5 mm or more, and may be 1 mm or more. The third surface may have only one first groove or multiple first grooves. In the latter case, the multiple first grooves are arranged along the depth direction Y of the battery. Also, as shown in FIG. 10, the current collecting terminal 20 may have a fourth surface S4 that extends from the outer edge of the first surface S1 toward the second surface S2 and faces the third surface S3. A second groove G2 is arranged on the fourth surface S4, with its bottom located at the center of the current collecting terminal 20. Details of the second groove G2 are the same as those described for the first groove G1. In the first modified example, the details other than the groove are the same as those described above. The battery in the first modified example may or may not have the above-mentioned connecting surface.

[0045] 4. Second Modification The present disclosure provides a battery comprising an electrode body, a current collecting terminal arranged on a side portion of the electrode body, and a laminate film covering the electrode body and the current collecting terminal, wherein the current collecting terminal has a first surface facing the electrode body, a second surface facing the first surface, and a third surface extending from the outer edge of the first surface toward the second surface, and the laminate film extends to the second surface while covering the third surface, and a portion of the second surface is not covered by the laminate film.

[0046] The current collecting terminal 20 shown in Fig. 11 has a first surface S1 facing the electrode body (not shown), a second surface S2 facing the first surface S1, and a third surface S3 extending from the outer edge of the first surface S1 toward the second surface S2. The laminate film 30 extends to the second surface S2 while covering the third surface S3. A portion of the second surface S2 is not covered by the laminate film 30, and current collection occurs there. Because the laminate film 30 extends to the second surface S2, the battery is able to suppress the intrusion of moisture.

[0047] As shown in FIG. 11, the third surface S3 and the end t 30The distance between the first surface S1 and the second surface S2 is defined as L4. L4 is, for example, 0.5 mm or more, and may be 1 mm or more. As shown in FIG. 11, the current collecting terminal 20 may extend from the outer edge of the first surface S1 toward the second surface S2 and have a fourth surface S4 facing the third surface S3. The laminate film 30 may extend to the second surface S2 while covering the fourth surface S4.

[0048] In the second modification, the details other than the position of the end of the laminate film are the same as those described above. The battery in the second modification may or may not have the above-mentioned connecting surface. In addition, the battery in the second modification may or may not have the groove that is a feature of the first modification.

[0049] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Explanation of symbols]

[0050] 10...Electrode body 20...Current collector terminal 30...Laminating film 40...Resin film 100...battery

Claims

1. An electrode body; a current collecting terminal disposed on a side surface of the electrode body; a laminate film covering the electrode body and the current collecting terminal; A battery comprising: the current collecting terminal has a first surface facing the electrode body, a second surface facing the first surface, a third surface extending from an outer edge of the first surface toward the second surface, a first connecting surface connecting the third surface and the second surface, a fourth surface extending from the outer edge of the first surface toward the second surface and facing the third surface, and a second connecting surface connecting the fourth surface and the second surface, When the battery is viewed in cross section in the thickness direction, the boundary between the third surface and the first connecting surface is B １ and the boundary between the first connecting surface and the second surface is B ２ and the boundary between the fourth surface and the second connecting surface is B ３ and the boundary between the second connecting surface and the second surface is B ４ In this case, the above B ２ is the thickness direction of the B １ Located more inward, ４ is the thickness direction of the B ３ Located further inside, the laminate film covers the third surface and the first connecting surface, and also covers the fourth surface and the second connecting surface; the first connecting surface and the second connecting surface each have a surface facing in the thickness direction, At least a part of the surface facing in the thickness direction is covered with the laminate film, The laminate film is in contact with the electrode body.

2. When the battery is viewed in cross section in the thickness direction, １ and B ２ are connected by a single straight line, multiple straight lines, or a curved line.

3. When the battery is viewed in cross section in the thickness direction, ３ and B ４ 3. The battery according to claim 1, wherein the lines are connected by one straight line, a plurality of straight lines, or a curved line.

4. a resin film is disposed between the current collecting terminal and the laminate film; 3. The battery according to claim 1, wherein an end of the resin film protrudes beyond an end of the laminate film.

5. An electrode body; a current collecting terminal disposed on a side surface of the electrode body; a laminate film covering the electrode body and the current collecting terminal; A battery comprising: the current collecting terminal has a first surface facing the electrode body, a second surface facing the first surface, and a third surface extending from an outer edge of the first surface toward the second surface, the laminate film extends to the second surface while covering the third surface, A portion of the second surface is not covered with the laminate film, The laminate film is in contact with the electrode body.

6. A battery as described in claim 1 or claim 5, wherein the outer edge shape of the collecting terminal when viewed from the depth direction of the battery is rectangular.

7. A battery as described in claim 1 or claim 5, wherein the outer edge shape of the electrode body when viewed from the depth direction of the battery is rectangular.

8. A battery as described in claim 1, wherein the laminate film covers the collector terminal along the third surface, the first connecting surface, the fourth surface and the second connecting surface.

9. The electrode body has a plurality of current collecting tabs, the current collecting tab has a root portion which is an end portion on the electrode body side, a connection portion for connecting to the current collecting terminal, and an intermediate portion which connects the root portion and the connection portion, 6. The battery according to claim 1, wherein the connection portions of the current collecting tabs each have a stacked connection portion in which the connection portions are stacked in a thickness direction of the current collecting tab.

10. A battery as described in claim 1 or claim 5, which is a lithium ion secondary battery.

Images