Battery, battery module, and method for manufacturing a battery
By fusing the laminate film on the side members to cover both the side member and electrode body edges, the battery design addresses the issue of wrinkles, maintaining sealing performance and integrity, especially with dimensionally mismatched components.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2025-04-28
- Publication Date
- 2026-05-15
Smart Images
Figure 0007859555000001 
Figure 0007859555000002 
Figure 0007859555000003
Abstract
Description
[Technical Field]
[0001] This disclosure relates to a battery, a battery module, and a method for manufacturing a battery. [Background technology]
[0002] Batteries such as lithium-ion secondary batteries typically comprise an electrode body 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 body is sealed in an internal space surrounded by an outer casing material, for example. Patent Document 1 discloses a lithium polymer secondary battery comprising an electrode assembly, an outer casing material surrounding the outside of the electrode assembly, and first and second covers sealing the outer casing material, with the first electrode terminal and second electrode terminal being led out to the outside via the first and second covers, respectively. Patent Document 1 also describes a laminate film as the outer casing material. [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] Japanese Patent Publication No. 2011-108623 [Overview of the project] [Problems that the invention aims to solve]
[0004] As shown in Figure 3, which will be described later, the dimensions of the side members may be smaller than the dimensions of the electrode body. If side members with such dimensional relationships are sealed with a laminate film, wrinkles may form in the laminate film, for example, which may reduce the sealing performance of the battery.
[0005] This disclosure is made in view of the above circumstances and primarily aims to provide a battery that suppresses a decrease in sealing performance. [Means for solving the problem]
[0006] [1] A battery comprising an electrode body, a side member disposed on a side surface portion of the electrode body, and a laminate film covering the electrode body, wherein when the battery is viewed from the side member side in a side view, an outer edge of the side member is located inside an outer edge of the electrode body, the laminate film is disposed so as to cover a surface constituting the outer edge of the side member and a surface constituting the outer edge of the electrode body, and a fusion portion where inner surfaces of the laminate film are fused to each other is disposed on the side member.
[0007] [2] The battery according to [1], wherein when the battery is viewed in a plan view from the thickness direction, the fusion portion is continuously disposed from an end position α of the laminate film on the side member side to a position β of the laminate film corresponding to a boundary between the side member and the electrode body.
[0008] [3] The battery according to [1] or [2], wherein when the battery is viewed from the side member side in a side view, in the thickness direction of the battery, a highest position P1 of the fusion portion is lower than a highest position P2 of the laminate film disposed on the electrode body.
[0009] [4] The battery according to any one of [1] to [3], wherein when the battery is viewed from the side member side in a side view, in the thickness direction of the battery, a highest position P1 of the fusion portion is lower than a highest position P3 of the electrode body.
[0010] [5] The battery according to any one of [1] to [4], wherein the fusion portion is disposed at a corner portion constituting the outer edge of the side member.
[0011] [6] The battery according to any one of [1] to [5], wherein when the battery is viewed from the side member side in a side view, a shape of the side member is a quadrangle.
[0012] [7] The battery according to any one of [1] to [6], wherein a plurality of the fusion parts are arranged on the side member.
[0013] [8] The battery according to any one of [1] to [7], wherein the side member is a current collecting terminal.
[0014] [9] The battery according to any one of [1] to [8], wherein the battery includes a pair of the side members, and the pair of the side members are arranged to face the electrode body.
[0015]
[10] The battery according to any one of [1] to [9], wherein when the battery is viewed from the side member side in a side view, the ratio (L2 / L1) of the length L2 of the outer edge of the side member to the length L1 of the outer edge of the electrode body is 0.7 or more and less than 1.
[0016]
[11] The battery according to any one of [1] to
[10] , wherein the electrode body has 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 in this order in the thickness direction.
[0017]
[12] A battery module having a plurality of batteries stacked in the thickness direction, wherein the battery is the battery according to any one of [1] to
[11] .
[0018]
[13] The battery module according to
[12] , wherein the battery module has a restraining jig for restraining a plurality of batteries in the thickness direction.
[0019]
[14] The battery module according to
[12] or
[13] , wherein in a pair of the side members adjacent to each other in the thickness direction, the main surface of the laminate film arranged on one of the side members and the main surface of the laminate film arranged on the other side member do not contact each other.
[0020]
[15] A method for manufacturing a battery according to any one of [1] to
[11] , comprising: a preparation step of preparing a structure having the electrode body and the side member; a first coating step of covering the surface constituting the outer edge of the electrode body in the structure with the laminate film; and a second coating step of covering the surface constituting the outer edge of the side member in the structure with the laminate film, wherein in the second coating step, the fused portion is formed using a jig that can make surface contact with the surface constituting the outer edge of the side member.
[0021]
[16] When the above battery is viewed from the side of the side member, the shape of the side member is rectangular, and the rectangle has a first side, a second side adjacent to the first side, a third side adjacent to the second side and facing the first side, and a fourth side adjacent to the third side and facing the second side, and the second coating step is a first adhesion process in which the first jig and the third jig are pressed into the first side and the third side of the side member, respectively, and the laminate film is adhered to the first side and the third side, respectively. The method for manufacturing a battery according to
[15] , further comprising: a second adhesion process, after the first adhesion process, the second jig and the fourth jig being pressed into the second side and the fourth side of the side member, respectively, to adhere the laminate film to the second side and the fourth side, respectively, wherein at least one of the first jig and the third jig has an elastic member, and in the second adhesion process, the elastic member is compressed and deformed by pressing in the second jig and the fourth jig to form the fused portion. [Effects of the Invention]
[0022] The battery described in this disclosure has the effect of suppressing a decrease in sealing performance. [Brief explanation of the drawing]
[0023] [Figure 1]This is a schematic perspective view illustrating the electrode body and side member in this disclosure. [Figure 2] This is a schematic perspective view illustrating the electrode body, side member, and laminate film in this disclosure. [Figure 3] These are schematic side views and schematic cross-sectional views illustrating the electrode body, side member, and laminate film in this disclosure. [Figure 4] This is a schematic side view illustrating a part of the battery described in this disclosure. [Figure 5] This is a schematic side view illustrating a part of the battery described in this disclosure. [Figure 6] This is a schematic plan view illustrating a part of the battery described in this disclosure. [Figure 7] This is a schematic perspective illustrating some of the batteries described in this disclosure. [Figure 8] These are schematic side views and schematic cross-sectional views illustrating some of the batteries described in this disclosure. [Figure 9] This is a schematic cross-sectional view illustrating a part of the battery described in this disclosure. [Figure 10] This is a schematic side view illustrating a part of the battery described in this disclosure. [Figure 11] This is a schematic cross-sectional view illustrating an example of an electrode body in this disclosure. [Figure 12] This is a schematic perspective view illustrating a battery module in this disclosure. [Figure 13] This is a schematic cross-sectional view illustrating an example of a battery module in this disclosure. [Figure 14] This is a schematic side view illustrating the second coating step in this disclosure. [Figure 15] This is a schematic side view illustrating the second coating step in this disclosure. [Figure 16] This is a schematic side view illustrating the second coating step in this disclosure. [Figure 17] This is a schematic side view illustrating the jig in this disclosure. [Modes for carrying out the invention]
[0024] The battery described herein will be explained in detail below with reference to the drawings. The following figures are schematic representations, and the size and shape of each part are exaggerated as appropriate for ease of understanding. In addition, in this specification, when describing how one component is positioned relative to another component, the terms "above" or "below" include, unless otherwise specified, both cases in which one component is positioned directly above or below another component so as to be in contact with that component, and cases in which one component is positioned above or below another component via another component.
[0025] A.Battery Figure 1 is a schematic perspective view illustrating the electrode body and side members in this disclosure. The electrode body 10 shown in Figure 1(a) has a top surface 11, a bottom surface 12 facing the top surface 11, and four side surfaces (first side surface 13, second side surface 14, third side surface 15, and fourth side surface 16) connecting the top surface 11 and the bottom surface 12. In Figure 1(b), a first side surface member 20A is positioned on the first side surface 13 of the electrode body 10, and a second side surface member 20B is positioned on the third side surface 15 of the electrode body 10. For example, the first side surface member 20A is a positive electrode current collector terminal, and the second side surface member 20B is a negative electrode current collector terminal.
[0026] Figure 2 is a schematic perspective view illustrating the electrode body, side members, and laminate film in this disclosure. As shown in Figure 2(a), the laminate film 30 is, for example, a single film. Also, as shown in Figures 2(a) and (b), the laminate film 30 is folded to cover the entire bottom portion 12, second side portion 14, top portion 11, and fourth side portion 16 of the electrode body 10. On the other hand, in Figure 2(b), at least a portion of the first side member 20A and at least a portion of the second side member 20B are located inside the folded laminate film 30.
[0027] Figure 3(a) is a schematic side view illustrating the electrode body and side member in this disclosure, and Figure 3(b) is a cross-sectional view AA of Figure 3(a). As shown in Figures 3(a) and (b), when the electrode body 10 and side member 20 are observed from the side of the side member 20, the outer edge E2 of the side member 20 is located inward from the outer edge E1 of the electrode body 10. That is, the dimensions of the side member 20 are smaller than the dimensions of the electrode body 10.
[0028] Figure 3(c) is a schematic side view illustrating the electrode body, side member, and laminate film in this disclosure, and Figure 3(d) is a cross-sectional view AA of Figure 3(c). As shown in Figures 3(c) and (d), when the electrode body 10, side member 20, and laminate film 30 are observed from the side of the side member 20, a space S is created between the laminate film 30 and the side member 20. Therefore, when the side member 20 is sealed with the laminate film 30, wrinkles may form in the laminate film 30 due to the excess portion of the laminate film 30, which may reduce the sealing performance of the battery. In contrast, as shown in Figure 4, the battery in this disclosure has a fused portion X on the side member 20 where the inner surfaces (sides facing the side member 20) of the laminate film 30 are fused together.
[0029] According to this disclosure, since the fused portion is arranged on the side member, the battery has suppressed a decrease in sealing performance. As shown in Figure 3 above, the dimensions of the side member may be smaller than the dimensions of the electrode body. By adopting such a dimensional relationship, it is possible to prevent adjacent side members from coming into contact when, for example, multiple batteries are stacked. By preventing contact between adjacent side members, battery damage becomes less likely. Furthermore, if side members with such a dimensional relationship are sealed with a laminate film, wrinkles may form in the laminate film, for example, reducing the sealing performance of the battery. In this disclosure, by arranging the fused portion X, where the inner surfaces of the laminate film are fused together, on the side member, the battery has suppressed a decrease in sealing performance even when the dimensions of the side member are smaller than the dimensions of the electrode body.
[0030] 1. Battery configuration The battery in this disclosure comprises at least an electrode body, a side member, and a laminate film.
[0031] (1) Electrode body The electrode body in this disclosure functions as a power generation element of a battery. The shape of the electrode body is not particularly limited, but for example, as shown in Figure 1(a), it has a top surface 11, a bottom surface 12 facing the top surface 11, and four side surfaces (first side surface 13, second side surface 14, third side surface 15, and fourth side surface 16) connecting the top surface 11 and the bottom surface 12. Both the top surface 11 and the bottom surface 12 correspond to the main surface of the electrode body, and the direction normal to the main surface can be defined as the thickness direction. The first side surface 13 and the third side surface 15 are arranged to face each other. Similarly, the second side surface 14 and the fourth side surface 16 are arranged to face each other.
[0032] The shape of the top surface is not particularly limited, but examples include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms. In Figure 1(a), the shape of the top surface 11 is a rectangle. The shape of the top surface may also be a polygon other than a quadrilateral, or a curved shape such as a circle. The shape of the bottom surface is the same as the shape of the top surface. The shape of the side surfaces is not particularly limited, but examples include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms.
[0033] (2) Side members In this disclosure, the side members are arranged on the side of the electrode body. The battery in this disclosure may have one side member for one electrode body, or it may have two or more side members. In the latter case, for example as shown in Figure 1(b), a pair of side members 20 (first side member 20A and second side member 20B) may be arranged facing each other with respect to the electrode body 10. Also in Figure 1(b), the pair of side members 20 are arranged facing each other in the longitudinal direction of the electrode body 10. On the other hand, although not specifically shown, the pair of side members may be arranged facing each other in the short direction of the electrode body.
[0034] The shape of the side member is not particularly limited, and examples thereof include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms. The shape of the side member 20 in Fig. 3(a) is a rectangle. In this rectangle, the short side extends along the direction parallel to the thickness direction D T and the long side extends along the direction perpendicular to the thickness direction D T . Further, the shape of the side member may be a polygon other than a quadrilateral, or a shape having a curve such as a circle. Also, the side member may have a corner where two sides (straight sides) intersect.
[0035] When the battery is viewed from the side member side in side view, the outer edge of the side member is located inside the outer edge of the electrode body. For example, as shown in Fig. 3(a), the outer edge E2 of the side member 20 is located inside the outer edge E1 of the electrode body 10. In other words, the outer edge E2 of the side member 20 is entirely surrounded by the outer edge E1 of the electrode body 10. Also, the dimensions of the side member 2 have smaller dimensions than those of the electrode body 10.
[0036] For example, in Fig. 3(a), let the length (total perimeter) of the outer edge E1 of the electrode body 10 be L1, and the length (total perimeter) of the outer edge E2 of the side member 20 be L2. The ratio of L2 to L1 (L2 / L1) is, for example, 0.7 or more and less than 1, and may be 0.8 or more and 0.95 or less. Also, for example, in Fig. 3(a), let the length of the outer edge E1 in the thickness direction D T be L a , and the length of the outer edge E2 in the thickness direction D T be L b . The ratio of L a to L b (L b / L a ) is, for example, 0.5 or more and less than 1, and may be 0.8 or more and 0.95 or less. Also, for example, in Fig. 3(a), let the length of the outer edge E1 in the direction perpendicular to the thickness direction D T be L c , and the length of the outer edge E2 in the direction perpendicular to the thickness direction D T be L d . The ratio of L c to L d (Ld / L c For example, δ may be 0.5 or greater and less than 1, or 0.8 or greater and 0.95 or less. Also, for example in Figure 3(a), let δ be the length of the gap between outer edge E1 and outer edge E2. δ may be greater than 0 mm, 0.3 mm or greater, or 0.5 mm or greater. On the other hand, δ may be 1.5 mm or less.
[0037] (3) Laminating film In this disclosure, the laminate film covers the electrode body and seals the electrode body together with the side member. As shown in Figure 2, when the electrode body 10 and the side member 20 are observed from the side of the side member 20, the laminate film 30 is positioned to cover the surface constituting the outer edge of the side member 20 and the surface constituting the outer edge of the electrode body 10. Also, as shown in Figure 4, a fused portion X is arranged on the side member 20 where the inner surfaces of the laminate film 30 are fused together. It is preferable that the fused surface in the fused portion X does not have any gaps. Also, in Figure 4, an end-adhesion portion Y is arranged where the ends of the laminate film 30 are fused together. The end-adhesion portion Y may be folded to match the shape of the side member, as this reduces excess space.
[0038] In Figure 5, when the battery 100 is viewed from the side of the side member 20, the fused portion X is positioned at the corner that constitutes the outer edge E2 of the side member 20. Specifically, the corner that constitutes the outer edge E2 of the side member 20 coincides with the end t of the fused surface in the fused portion X. Also, as shown in Figure 5, let w be the width of the fused surface in the fused portion X. The width w is, for example, 0.1 mm or more, may be 0.3 mm or more, or may be 0.6 mm or more. On the other hand, the width w is, for example, 1.2 mm or less.
[0039] As shown in Figures 6 and 7, when the battery 100 is viewed from above in the thickness direction, the end position of the laminate film 30 on the side member 20 side is denoted as α, and the position of the laminate film 30 corresponding to the boundary between the side member 20 and the electrode body 10 is denoted as β. In Figures 6 and 7, the fused portion X is arranged continuously from end position α to position β. Furthermore, if the direction in which the side member 20 extends from the electrode body 30 is denoted as D1, it is preferable that the fused portion X is arranged along direction D1. In addition, the fused portion X may be arranged in at least a portion of the area from end position α to position β in direction D1. The length of the fused portion X in direction D1 is, for example, 1 mm or more, may be 3 mm or more, or may be 5 mm or more.
[0040] Figure 8(a) is a schematic side view of a portion of the battery 100 viewed from the side member 20 side, and Figure 8(b) is a cross-sectional view AA of Figure 8(a). As shown in Figures 8(a) and (b), the thickness direction D of the battery 100 T In this diagram, the highest position of the fusion portion X is defined as P1, the highest position of the laminate film 30 placed on the electrode body 10 is defined as P2, and the highest position of the electrode body 10 is defined as P3. In Figures 8(a) and (b), position P1 is in the thickness direction D T In this case, it is lower than position P2. Also, in Figures 8(a) and (b), position P1 is in the thickness direction D T In this case, it is lower than position P3, but may be the same as position P3, or may be higher than position P3. Also, position P1 is in the thickness direction D T In this case, the position may be lower than the position of the top surface of the electrode body 10.
[0041] Figure 8(c) is a schematic side view of a portion of the battery 100 viewed from the side of the side member 20, and Figure 8(d) is a cross-sectional view of AA in Figure 8(c). The fused portion X in Figures 8(a) and (b) described above is located at the corner of the side member 20. On the other hand, as shown in Figures 8(c) and (d), the fused portion X is located in the thickness direction D of the side that constitutes the outer edge of the side member 20. TIt may also be positioned on an edge extending in a direction intersecting with the direction. Furthermore, in Figures 8(c) and (d), the fusion portion X is positioned on the long side (the long side on the top surface side of the electrode body) that constitutes the outer edge of the side member 20. Even when the fusion portion X is positioned in such a location, position P1 is in the thickness direction D T In this case, it is preferable that it is lower than position P2. Also, in Figures 8(c) and (d), position P1 is in the thickness direction D T In this case, the position is higher than position P3, but may be the same as position P3, or lower than position P3. Also, position P1 is in the thickness direction D T In this case, the position may be lower than the position of the top surface of the electrode body 10.
[0042] As shown in Figure 9(a), the end position α of the laminate film 30 on the side member 20 side may be closer to the electrode body 10 than the end position γ of the side member 20 on the opposite side from the electrode body 10. That is, when the battery is viewed in plan from the thickness direction, the laminate film 30 may cover a part of the side member 20. In this case, a part of the side member 20 (the part not covered by the laminate film 30) will be exposed. On the other hand, as shown in Figure 9(b), the end position α may coincide with the end position γ. That is, when the battery is viewed in plan from the thickness direction, the laminate film 30 may cover the entire side member 20.
[0043] Figures 10(a) to 10(d) are schematic side views of a portion of the battery 100, viewed from the side of the side member 20. As shown in Figure 10(a), the fusion portion X is located at the corner that forms the outer edge of the side member 20. Although two fusion portions X are shown in Figure 10(a), there may be one fusion portion X per side member 20, or there may be three or more fusion portions X. In particular, it is preferable to have multiple fusion portions X per side member 20, because this allows for the distribution and absorption of excess portions of the laminate film 30. In addition, the end adhesion portion Y in Figure 10(a) is formed by the fusion of the ends of the laminate film 30 by bringing their inner surfaces into contact.
[0044] As shown in Figure 10(a), the two fused portions X may be positioned at the two corners of one short side that constitutes the outer edge of the side member 20. Alternatively, as shown in Figure 10(b), the two fused portions X may be positioned at the two corners of one long side that constitutes the outer edge of the side member 20. Furthermore, as shown in Figure 10(c), the four fused portions X may be positioned at the four corners that constitute the outer edge (square) of the side member 20. In Figure 10(c), the end-contact portion Y is formed when the ends of the laminate film 30 are in contact with each other, with one inner surface and the other outer surface touching. Additionally, as shown in Figure 10(d), the fused portions X may be positioned in the middle of the sides (parts other than corners) that constitute the outer edge of the side member 20.
[0045] 2. Battery components The battery in this disclosure comprises an electrode body, a side member, and a laminate film.
[0046] (1) Electrode body The electrode body in this disclosure typically has 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 in this order in the thickness direction. For example, the electrode body 10 shown in Figure 11 has a positive electrode current collector 4, a positive electrode active material layer 1, an electrolyte layer 3, a negative electrode active material layer 2, and a negative electrode current collector 5 in this order in the thickness direction.
[0047] 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 positive electrode active materials include oxide active materials. Examples of oxide active materials include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Examples of active materials include rock salt layered types 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 shape of the positive electrode active material is, for example, particulate.
[0048] 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 (electrolyte solution) may contain, 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.
[0049] 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 negative electrode active materials include metallic active materials such as Li and Si, carbon active materials such as graphite, and Li4Ti5O 12 Examples of oxide active materials include the following. The shape of the negative electrode active material is, for example, particulate or foil-like. The conductive material, electrolyte, and binder are the same as described above.
[0050] The electrolyte layer is positioned 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 as described above. The electrolyte layer may have a separator.
[0051] The positive electrode current collector collects current from the positive electrode active material layer. Examples of materials for the positive electrode current collector include metals such as aluminum, stainless steel, and nickel. Examples of shapes for the positive electrode current collector include foil-like and mesh-like forms. The positive electrode current collector may have a positive electrode tab for connecting to the positive electrode current collection terminal.
[0052] The negative electrode current collector collects current from the negative electrode active material layer. Examples of materials for the negative electrode current collector include metals such as copper, stainless steel (SUS), and nickel. Examples of shapes for the negative electrode current collector include foil-like and mesh-like forms. The negative electrode current collector may also have a negative electrode tab for connecting to the negative electrode current collection terminal.
[0053] (2) Side members The side member in this disclosure is arranged on the side of the electrode body. The side member is not particularly limited as long as it is arranged on the side of the electrode body, but it is preferably a current collector terminal. A current collector terminal is a terminal having a current collector portion in at least part of it. The current collector portion is electrically connected to a tab on the electrode body, for example. The current collector terminal may be entirely a current collector portion, or only a part of it may be a current collector portion. The side member may also be an exterior member that does not have a current collector function. Examples of materials for the side member include metals such as SUS.
[0054] (3) Laminating film The laminate film in this disclosure has at least a structure in which a heat-sealable layer and a metal layer are laminated. The laminate film may also have the heat-sealable layer, metal layer and resin layer in this order along the thickness direction. Examples of materials for the heat-sealable layer include olefin resins such as polypropylene (PP) and polyethylene (PE). Examples of materials for the metal layer include aluminum, aluminum alloys and stainless steel. Examples of materials for the resin layer include polyethylene terephthalate (PET) and nylon. The thickness of the heat-sealable layer is, for example, 40 μm to 100 μm. The thickness of the metal layer is, for example, 30 μm to 60 μm. The thickness of the resin layer is, for example, 20 μm to 60 μm. The thickness of the outer casing is, for example, 80 μm to 250 μm.
[0055] (4)Battery The battery in this disclosure is typically a lithium-ion secondary battery. Applications of the battery include, for example, powering vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. It is particularly preferable for the battery to be used as a power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). Furthermore, the battery in this disclosure may be used as a power source for mobile devices other than vehicles (e.g., railways, ships, aircraft), or as a power source for electrical products such as information processing devices.
[0056] B. Battery Olive Figure 12 is a schematic perspective view illustrating a battery module in this disclosure. The battery module 200 shown in Figure 12 has a thickness direction D T It has multiple batteries 100 stacked on top of each other. The batteries 100 are the batteries described in "A. Batteries" above.
[0057] According to this disclosure, using the aforementioned battery results in a battery module that suppresses a decrease in sealing performance.
[0058] The battery in this disclosure is the same as described in "A. Battery" above, so a further explanation is omitted here. Furthermore, the battery module in this disclosure may have a restraining fixture that restrains multiple batteries in the thickness direction. The type of restraining fixture is not particularly limited, but examples include fixtures that apply restraining torque using bolts. The restraining pressure applied by the restraining fixture is, for example, 1 MPa or more and 50 MPa or less.
[0059] As shown in Figure 13, the laminate film 30 placed on the side member 20 has a main surface portion 31 and a wall portion 32. The wall portion 32 is located between the main surface portion 31 and position β of the laminate film 30, which corresponds to the boundary between the side member 20 and the electrode body 10. Furthermore, when restraining pressure is applied to the battery by the restraining jig, the battery is compressed in the thickness direction. In such a state, the thickness direction D TIn a pair of adjacent side members 20 (20C, 20D), it is preferable that the main surface portion 31 of the laminate film 30 placed on one side member 20C and the main surface portion 31 of the laminate film 30 placed on the other side member 20D are not in contact. This is because it prevents damage due to contact. Also, if a fusion portion is placed on the main surface portion of the laminate film, that fusion portion is included in the main surface portion of the laminate film. That is, it is preferable that the fusion portion placed on the main surface portion of the laminate film is not in contact with the main surface portion of the laminate film placed on the other side member. Furthermore, in a state where restraining pressure is applied to the battery by the restraining jig, the above-mentioned position P1 may be lower than the above-mentioned position P2, and may also be lower than the above-mentioned position P3.
[0060] C. Battery manufacturing method The battery manufacturing method in this disclosure is the battery manufacturing method described above, comprising: a preparation step of preparing a structure having the electrode body and the side member; a first coating step of covering the outer edge of the electrode body in the structure with the laminate film; and a second coating step of covering the outer edge of the side member in the structure with the laminate film, wherein in the second coating step, the fused portion is formed using a jig that can make surface contact with the surface constituting the outer edge of the side member.
[0061] According to this disclosure, a battery with suppressed deterioration in sealing performance can be obtained by forming a fused portion.
[0062] 1. Preparation process The preparation step in this disclosure is the step of preparing a structure having the electrode body and the side member described above. The electrode body and side member are the same as those described in "A. Battery" above, so their explanation is omitted here.
[0063] 2. First coating process The first coating step in this disclosure is a step of covering the outer edge of the electrode body in the structure with the laminate film. For example, as shown in Figures 2(a) and (b), in the first coating step, the surfaces constituting the outer edge of the electrode body 10 (for example, the bottom surface 12, the second side surface 14, the top surface 11, and the fourth side surface 16) are covered with the laminate film 30. At this time, the electrode body 10 and the laminate film 30 may be brought into close contact. Also, as shown in Figure 2(b), the overlapping end portion Z where the ends of the laminate film 30 overlap is heated. This forms an end-contact portion Y where the ends of the laminate film 30 are fused together. The laminate film may be pre-folded to match the shape of the electrode body.
[0064] Furthermore, in the first coating process, a space S is usually created between the laminate film 30 and the side member 20, as shown in Figures 3(c) and (d). This space S disappears in the second coating process, which will be described later, and a fused portion is formed in its place.
[0065] 3. Second coating process The second coating step in this disclosure is a step of covering the surface constituting the outer edge of the side member with the laminate film. In addition, a fused portion is formed in the second coating step.
[0066] In the second coating step, the side member and the laminate film are brought into close contact using a jig that can make surface contact with the surface constituting the outer edge of the side member. Figure 14 is a schematic side view illustrating the second coating step in this disclosure. As shown in Figure 14(a), the first coating step described above has formed a space S between the laminate film 30 and the side member 20. Also, the first coating step described above has formed an end contact portion Y. Next, as shown in Figure 14(b), jigs 41, 42, 43, and 44 are pressed against the laminate film 30 and the side member 20. It is preferable that jigs 41 to 44 are heated. Thickness direction D TIn this configuration, the length of the jig 42 (length in the vertical direction of the drawing) is shorter than the length of the side member 20 (length in the vertical direction of the drawing). As a result, a gap is created between the jig 41 and the jig 42, and the excess portion of the laminate film 30 accumulates in this gap. This forms a fused portion X, as shown in Figure 14(c).
[0067] Furthermore, if the side view shape of the side member is rectangular, the second coating step may include the first and second adhesion processes described later. For example, as shown in Figure 15(a), the side view shape of the side member 20 is rectangular. This rectangle has a first side s1, a second side s2 adjacent to the first side s1, a third side s3 adjacent to the second side s2 and facing the first side s1, and a fourth side s4 adjacent to the third side s3 and facing the second side s2. In Figure 15(a), the first side s1 and the third side s3 correspond to the short sides that constitute the outer edge of the side member 20, and the second side s2 and the fourth side s4 correspond to the long sides that constitute the outer edge of the side member 20.
[0068] Next, as shown in Figure 15(b), the first jig 41 and the third jig 43 are pressed into the first side s1 and the third side s3 of the side member 20, respectively. This causes the laminate film 30 to adhere closely to the first side s1 and the third side s3, respectively (first adhesion process). In Figure 15(b), the first jig 41 and the third jig 43 each have a first elastic member 51 and a third elastic member 53, respectively. Examples of materials for the elastic members include silicone rubber and fluororubber.
[0069] Next, as shown in Figures 15(c) and (d), the second jig 42 and the fourth jig 44 are pressed into the second side s2 and fourth side s4 of the side member 20, respectively. This causes the laminate film 30 to adhere closely to the second side s2 and the fourth side s4, respectively (second adhesion process). At this time, pressing in the second jig 42 and the fourth jig 44 compresses and deforms the first elastic member 51 and the third elastic member 53. As a result, the fused portion X is formed, as shown in Figure 15(e).
[0070] The process by which the fused portion X is formed will be explained using Figure 16. As shown in Figure 16(a), in the first adhesion process, a jig 45 having an elastic member 55 is pressed into the side member 20. While maintaining this state, as shown in Figure 16(b), in the second adhesion process, the elastic member 55 is compressed and deformed by the jig 46. At this time, since the elastic member 55 is softer than the side member 20, jig 45 and jig 46, it is preferentially compressed and deformed, and in accordance with this compression deformation, the excess portion of the laminate film 30 is folded, and the fused portion X is formed.
[0071] In this disclosure, it is preferable that the first and third sides correspond to the short sides that constitute the outer edge of the side member 20, and the second and fourth sides correspond to the long sides that constitute the outer edge of the side member 20. In this case, in the first sealing process, the first and third jigs, which are not heated, may be pressed in, and in the second sealing process, the second and fourth jigs, which are heated, may be pressed in. By heating the entire outer edge of the side member 20 only with heat input from the jigs on the long sides (second and fourth jigs), the structure of the sealing machine can be simplified.
[0072] As shown in Figure 17(a), with the jig 45 having the elastic member 55 pressed in, the thickness direction D T In this configuration, it is preferable that the position P5 of the vertex of the end of the elastic member 55 on the side member 20 side is higher than the position P6 of the vertex of the end of the side member 20 on the elastic member 55 side. By satisfying the relationship P5 > P6, the inner surfaces of the laminate film 30 are strongly compressed together, forming a fused portion with better sealing properties. That is, in the thickness direction D T The lengths of the elastic member 55 and the jig 45 in the thickness direction D T It is preferable that the length of the elastic member 55 is longer than the length of the side member 20. Also, in Figure 17(a), a part of the elastic member 55 is positioned between the jig 45 and the side member 20. On the other hand, as shown in Figure 17(b), the elastic member 55 does not have to be positioned between the jig 45 and the side member 20. Also, as shown in Figure 17(c), a notch 55a may be provided at the end t5 of the elastic member 55 on the side member 20 side. By providing the notch 55a, the fused portion can be formed stably.
[0073] 4.Battery The battery obtained through the process described above is the same as described in "A. Battery" above, so it will not be described here.
[0074] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Explanation of Symbols]
[0075] 1...Cathode active material layer 2...Negative electrode active material layer 3...Electrolyte layer 4...Positive electrode current collector 5...Negative electrode current collector 10...Electrode body 11...Top part 12…Bottom part 13...First side part 14…Second side part 15…Third side part 16…Fourth side part 20... Side members 30... Laminating film 100...battery 200... Battery Module
Claims
1. Electrode body and A side member arranged on the side surface of the electrode body, A single laminate film covering the electrode body, A battery equipped with, When the battery is viewed from the side of the side member, the outer edge of the side member is located inward from the outer edge of the electrode body. The laminate film is arranged to cover the surface constituting the outer edge of the side member and the surface constituting the outer edge of the electrode body. Three fused portions are arranged on the side member, where the inner surfaces of the laminate film are fused together. When the battery is viewed from the side of the side member, the shape of the side member is rectangular. Each of the three fused portions is located at three of the four corners that make up the outer edge of the side member. A battery in which the end-bonded portion where the ends of the laminate film are fused together is located at the corner of the side member where three of the four corners are not located.
2. The battery according to claim 1, wherein, when the battery is viewed in plan from the thickness direction, the fused portion is continuously arranged from the end position α of the laminate film on the side member side to the position β of the laminate film corresponding to the boundary between the side member and the electrode body.
3. When the battery is viewed from the side of the side member, the highest position P of the fused portion in the thickness direction of the battery is １ However, the highest position P of the laminate film arranged on the electrode body. ２ A battery according to claim 1, which is lower in value.
4. When the battery is viewed from the side of the side member, the highest position P of the fused portion in the thickness direction of the battery is １ However, the highest position P of the electrode body ３ A battery according to claim 1, which is lower in value.
5. The battery according to claim 1, wherein the side member is a current collection terminal.
6. The battery comprises a pair of the side members, The battery according to claim 1, wherein the pair of side members are arranged to face the electrode body.
7. When the battery is viewed from the side of the side member, the length L of the outer edge of the electrode body is... １ The length L of the outer edge of the side member relative to the length L ２ The proportion (L ２ / L １ The battery according to claim 1, wherein the ratio is 0.7 or greater and less than 1.
8. The battery according to claim 1, wherein the electrode body comprises 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 in this order in the thickness direction.
9. A battery module having multiple batteries stacked in the thickness direction, A battery module wherein the battery is the battery described in any of claims 1 to 8.
10. The battery module according to claim 9, wherein the battery module has a restraining jig for restraining a plurality of batteries in the thickness direction.
11. The battery module according to claim 10, wherein in a pair of adjacent side members in the thickness direction, the main surface portion of the laminate film disposed on one side member and the main surface portion of the laminate film disposed on the other side member are not in contact.