Battery

Abstract

To provide a battery capable of suppressing communication between the inside and the outside of the battery.SOLUTION: The battery 10 includes plate-shaped positive electrode-side collector terminals 14 configured to include a contact portion 14A capable of contacting a power supply target and disposed on one end portion side of the battery 10 in a first direction, and a base portion 14A provided continuously with the contact portion 14A on a central portion side of the contact portion 14B in the first direction of the battery 10, and a positive electrode-side tab film 18 in which a protrusion portion 14B protruding from a corner portion 14B1 provided at an end portion of the base portion 18C in a second direction is formed and which is disposed around the base portion 14B in a state of being welded to the base portion 14B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 below discloses an invention related to a secondary battery. In this secondary battery, the electrode assembly and electrolyte are covered with a sealing part configured to include an exterior material and a pair of covers. [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] In the prior art disclosed in Patent Document 1, the exterior material is folded to cover the side surfaces of the electrode assembly, and a pair of covers cover the ends of the electrode assembly. At the boundary between the exterior material and the cover, the exterior material covers the cover from the outside.

[0005] However, when the above-described configuration is adopted, it is conceivable that a gap will be generated between the corner of the folded exterior material and the cover, resulting in communication between the inside and outside of the battery.

[0006] In consideration of the above, an object of the present invention is to provide a battery that can prevent communication between the inside and outside of the battery. [Means for solving the problem]

[0007] The battery of the present invention described in claim 1 comprises an electrode body, a laminate sheet wrapped around the electrode body, extending away from the electrode body and having a welded portion where the ends are welded together, and a side component arranged on a side surface of the electrode body on one side in a first direction, wherein the laminate sheet covers the electrode body and the surface of the side component in the thickness direction of the electrode body and on one side in a second direction perpendicular to the first direction, and a protrusion protrudes from a corner provided at the end of the side component on one side in the second direction, the welded portion is arranged on one side of the side component in the second direction, the protrusion is inserted between the ends of the laminate sheet and joined to the laminate sheet, and one of the ends of the laminate sheet is curved at the starting point where it bends from the side surface.

[0008] The battery of the present invention described in claim 2 is the invention described in claim 1, wherein the laminate sheet is cylindrical with an opening and the electrode body is housed inside, and the side surface component includes a base portion arranged on one side of the electrode body in a first direction and a tab film welded around the base portion, and the electrode body is sealed within the laminate sheet by welding the tab film to the laminate sheet.

[0009] The battery of the present invention described in claim 3 is the invention described in claim 1, wherein the surface of the protrusion on one side in the thickness direction is flat and the surface on the other side in the thickness direction is curved. [Effects of the Invention]

[0010] As described above, the battery according to the present invention has the excellent effect of preventing communication between the inside and outside of the battery. [Brief explanation of the drawings]

[0011] [Figure 1] 2 is an enlarged cross-sectional view (enlarged view of the portion surrounded by the two-dot chain line in FIG. 2) showing a schematic configuration of a main part of the battery according to the present embodiment. [Figure 2]2 is a cross-sectional view (a cross-sectional view showing a state cut along line 2-2 in FIG. 3) that schematically shows the configuration around the tab lead of the battery according to the present embodiment. [Figure 3] FIG. 1 is a plan view schematically illustrating the configuration of a battery according to an embodiment of the present invention. [Figure 4] 1A to 1D are explanatory diagrams showing the steps of attaching a tab film to a battery according to this embodiment, where (A) shows the first step, (B) shows the second step, (C) shows the third step, and (D) shows the fourth step. [Figure 5] FIG. 2 is an enlarged cross-sectional view showing the configuration of a jig used in the step of attaching the tab film in the battery according to the present embodiment. [Figure 6] 1A and 1B are explanatory diagrams showing the steps of attaching a laminate sheet to a battery according to this embodiment, where (A) shows the first step, (B) shows the second step, (C) shows the third step, and (D) shows the fourth step. DETAILED DESCRIPTION OF THE INVENTION

[0012] An example of an embodiment of a battery 10 to which the battery tab lead structure according to the present invention is applied will be described below with reference to Figs. 1 to 6. As shown in Fig. 3, the battery 10 is, for example, a laminated lithium-ion secondary battery. Hereinafter, the longitudinal direction of the battery 10 will be referred to as the first direction, the lateral direction of the battery 10 will be referred to as the second direction, and the thickness direction of the battery 10 will be referred to as the third direction. In each drawing, the first direction is indicated by arrow X, the second direction is indicated by arrow Y, and the third direction is indicated by arrow Z.

[0013] The battery 10 includes an electrode assembly 12, an electrolyte layer (not shown), a positive electrode collector terminal 14, a negative electrode collector terminal 16, a positive electrode tab film 18, a negative electrode tab film 20, and an exterior part 22.

[0014] Specifically, the electrode body 12 is a laminated electrode body configured by stacking a plurality of sheet-shaped positive electrode bodies (not shown) and a plurality of sheet-shaped negative electrode bodies (not shown) in a third direction. The positive electrode bodies and negative electrode bodies are alternately stacked while being insulated from each other. Alternatively, the positive electrode body and negative electrode body may each be a single sheet.

[0015] The positive electrode body includes a positive electrode current collector and a positive electrode active material layer provided on the surface thereof. The positive electrode current collector is made of, for example, aluminum. The positive electrode active material layer contains a positive electrode active material (e.g., a lithium transition metal composite oxide such as a lithium nickel cobalt manganese composite oxide).

[0016] The negative electrode body includes a negative electrode current collector and a negative electrode active material layer formed on the surface thereof. The negative electrode current collector is made of, for example, copper. The negative electrode active material layer contains a negative electrode active material (e.g., a carbon material such as graphite).

[0017] Furthermore, the electrode body 12 is provided with a positive electrode current collector tab and a negative electrode current collector tab (not shown). More specifically, the positive electrode current collector tab is configured by a portion of the positive electrode current collector extending to one side in the first direction, and the end face of the positive electrode current collector tab on one side in the first direction is in contact with the positive electrode current collector terminal 14. In other words, the end face of the positive electrode current collector tab on one side in the first direction can be considered to constitute the side face of the electrode body 12 on one side in the first direction. Note that no positive electrode active material layer is provided on the positive electrode current collector tab.

[0018] On the other hand, the negative electrode current collector tab is configured by a portion of the negative electrode current collector extending to the other side in the first direction, and the end face of the negative electrode current collector tab on the other side in the first direction is in contact with the negative electrode current collector terminal 1. In other words, the end face of the negative electrode current collector tab on the other side in the first direction can be considered to constitute the side face of the electrode body 12 on the other side in the first direction. Note that no negative electrode active material layer is provided on the negative electrode current collector tab.

[0019] The electrolyte layer may be a liquid electrolyte layer, a gel-based electrolyte layer, a solid electrolyte layer, or the like, but in this embodiment, as an example, the electrolyte layer is a solid electrolyte layer containing a solid electrolyte, and a major portion of the electrolyte layer is disposed between the positive electrode active material layer and the negative electrode active material layer. Note that the type of solid electrolyte is not particularly limited as long as it has ion conductivity.

[0020] When a liquid electrolyte layer is used, a separator may be disposed between the positive electrode body and the negative electrode body to insulate the positive electrode active material layer from the negative electrode active material layer. The separator may be, for example, a sheet material made of a resin such as polyethylene (hereinafter referred to as PE) or polypropylene (hereinafter referred to as PP).

[0021] The positive electrode collector terminal 14 is made of aluminum and has a thin plate shape with the plate thickness direction as the third direction. The positive electrode collector terminal 14 includes a pair of contact portions 14A arranged on one end side of the battery 10 in the first direction, and a base portion 14B provided contiguous with the contact portions 14A on the central side of the battery 10 in the first direction.

[0022] The contact portion 14A is capable of coming into contact with a power-receiving object (not shown), and power is supplied from the battery 10 to the power-receiving object via the contact portion 14A.

[0023] On the other hand, the base portion 14B is joined to the positive electrode current collecting tab at a joint not shown by resistance welding or the like, with its end face on the other side in the first direction in contact with the end face on one side in the first direction of the positive electrode current collecting tab.

[0024] The negative electrode current collector terminal 16 is made of copper and has a thin plate shape with the plate thickness direction as the third direction. This negative electrode current collector terminal 16 includes a pair of contact portions 16A located on the other end side of the battery 10 in the first direction, and a base portion 16B provided contiguous with the contact portions 16A on the central side of the battery 10 in the first direction.

[0025] The contact portion 16A is capable of coming into contact with a power-receiving object (not shown), and power is supplied from the battery 10 to the power-receiving object via the contact portion 16A.

[0026] On the other hand, the base portion 16B is joined to the negative electrode current collecting tab at a joint not shown by resistance welding or the like, with its end face on one side in the first direction in contact with the end face on the other side in the first direction of the negative electrode current collecting tab.

[0027] 1 and 2, the positive electrode side tab film 18 is disposed in close contact with the periphery of the base portion 14B of the positive electrode side current collector terminal 14. The positive electrode side tab film 18 as a whole has a rectangular cylindrical shape with its axial direction in the first direction, and is configured to include a surface layer 18A that forms the surface side portion thereof, and a welding layer 18B that forms the base portion 14B side portion thereof and is welded to the base portion 14B.

[0028] The surface layer 18A is made of a resin such as polyethylene terephthalate (hereinafter referred to as PET) that has excellent water resistance, moisture resistance, and gas barrier properties, and the welding layer 18B is made of a resin such as PP that has excellent heat welding properties.

[0029] In this embodiment, in a cross section of the positive electrode side tab film 18 viewed from the first direction, four protrusions 18C are formed on the positive electrode side tab film 18. More specifically, the protrusions 18C are provided at the end on one side in the second direction and the end on the other side in the second direction of the base portion 14B of the positive electrode side current collector terminal 14, respectively, for each of the corners 14B1.

[0030] Furthermore, the protrusion 18C provided at the corner 14B1 on one side in the second direction protrudes from the corner 14B1 to one side in the second direction, and is made thinner toward one side in the second direction.

[0031] On the other hand, the protrusion 18C provided at the corner 14B1 on the other side in the second direction protrudes from the corner 14B1 toward the other side in the second direction, and is made thinner toward the other side in the second direction.

[0032] The negative electrode side tab film 20 has the same configuration as the positive electrode side tab film 18, and is disposed in close contact with the periphery of the base portion 16B of the negative electrode side current collector terminal 16. Although not shown in detail, the negative electrode side tab film 20 is also provided with four protrusions 20A, similar to the positive electrode side tab film 18.

[0033] The exterior part 22 is mainly formed by folding a single laminate sheet 24 into a rectangular tube shape with the axial direction as the first direction, and although not shown in detail, it is formed by stacking a protective layer, a metal layer, and a welding layer in that order from the outside of the battery 10.

[0034] The protective layer is made of resin such as nylon or PET, the metal layer is made of aluminum or stainless steel, and the welding layer is made of resin such as PP or PE.

[0035] In this embodiment, by folding the laminate sheet 24, four corners 24A are formed on the laminate sheet 24 in a cross section of the laminate sheet 24 viewed from the first direction. The protrusions 18C of the positive electrode side tab film 18 or the protrusions 20A of the negative electrode side tab film 20 are inserted into these corners 24A, respectively.

[0036] (Actions and Effects of This Embodiment) Next, the operation and effects of this embodiment will be described.

[0037] 3, the present embodiment includes a plate-shaped positive electrode collector terminal 14 including a contact portion 14A and a base portion 14B. The contact portion 14A is disposed on one end side of the battery 10 in the first direction and is capable of coming into contact with an object to be supplied with power.

[0038] On the other hand, the base portion 14B is provided contiguous with the contact portion 14A on the first direction central side of the battery 10. A positive electrode side tab film 18 is disposed around the periphery of the base portion 14B and is welded to the base portion 14B.

[0039] Incidentally, when an exterior material such as a laminate sheet is attached to the base portion 14B from the outside of the positive electrode side tab film 18, depending on how the exterior material is folded, a gap may occur between the corner of the folded exterior material and the positive electrode side tab film 18.

[0040] Here, in this embodiment, as shown in Figure 1, a protrusion 18C is formed on the positive electrode side tab film 18, and this protrusion 18C protrudes from a corner 14B1 provided at the end of the base portion 14B in the second direction.

[0041] Therefore, in this embodiment, the protrusion 18C of the positive electrode side tab film 18 enters the corner 24A of the folded laminate sheet 24 from the positive electrode side current collecting terminal 14 side, thereby preventing a gap from occurring between the corner 24A of the folded laminate sheet 24 and the positive electrode side tab film 18.

[0042] In this embodiment, the protrusion 18C of the positive electrode side tab film 18 protrudes in the second direction from a corner 14B1 provided at the end of the base portion 14B in the second direction. Therefore, when the batteries 10 are stacked in the third direction, the direction in which the batteries 10 are stacked is different from the direction in which the corner 24A of the laminate sheet 24 into which the protrusion 18C of the positive electrode side tab film 18 is inserted protrudes, thereby preventing the corner 24A of the laminate sheet 24 of one battery 10 from interfering with the other battery 10.

[0043] The above-described functions and effects are similarly achieved between the negative electrode tab film 20 and the laminate sheet 24.

[0044] Next, the process for attaching the positive electrode side tab film 18 and the negative electrode side tab film 20 and the process for attaching the laminate sheet 24 will be described mainly with reference to Figures 4 to 6. Since the process for attaching the positive electrode side tab film 18 and the process for attaching the negative electrode side tab film 20 are similar processes, only the process for attaching the positive electrode side tab film 18 will be described below.

[0045] 4(A), in the process of attaching the positive electrode tab film 18, the first film 26 is placed above the base portion 14B of the positive electrode collector terminal 14 in the third direction, with the PET layer facing away from the positive electrode collector terminal 14. Then, a plate-shaped upper jig 28 is placed above the first film 26 in the third direction so as to cover the base portion 14B when viewed from the third direction.

[0046] Additionally, the second film 30 is disposed below the base portion 14B in the third direction so that the PET layer is on the opposite side to the positive electrode-side current collecting terminal 14. Then, a plate-shaped lower jig 32 is disposed below the second film 30 in the third direction so as to cover the base portion 14B when viewed from the third direction.

[0047] Additionally, a plate-shaped first horizontal jig 34 whose thickness in the third direction is approximately the same as the thickness of the base portion 14B in the third direction is disposed on one side in the second direction relative to the base portion 14B.

[0048] 5, a pair of first protrusions 34A protruding in the third direction are provided at the end on the other side in the second direction of the first horizontal jig 34. More specifically, the protrusions 34A have rounded or squared corners 34A1 on one side in the second direction and the other side in the second direction.

[0049] Then, the third film 36 is temporarily fixed to the other side of the first horizontal jig 34 in the second direction in a curved or bent state so that it is convex toward the positive electrode side collector terminal 14, with the PET layer facing away from the positive electrode side collector terminal 14.

[0050] Further, a second horizontal jig 38 having a configuration similar to that of the first horizontal jig 34 is disposed on the other side in the second direction relative to the base portion 14B. Note that at this time, a pair of protrusions 38A as second protrusions provided on the second horizontal jig 38 are positioned on the positive electrode side current collector terminal 14 side.

[0051] Then, the fourth film 40 is temporarily fixed to one side of the second direction of the second horizontal jig 38 in a state in which it is curved or bent so as to be convex toward the positive electrode side collector terminal 14, and the PET layer is on the opposite side to the positive electrode side collector terminal 14.

[0052] 4(B), the upper jig 28, the lower jig 32, the first horizontal jig 34, and the second horizontal jig 38 are placed in predetermined positions. In this state, the first film 26 and the second film 30 are in contact with the third film 36 and the fourth film 40, respectively.

[0053] 4(C), the upper jig 28 is pressed from above in the third direction and the lower jig 32 is pressed from below in the third direction by a hot press 42. As a result, the first film 26, the second film 30, the third film 36, and the fourth film 40 are integrated, and the positive electrode side tab film 18 is formed around the base portion 14B.

[0054] At this time, the first film 26 and the third film 36 are sandwiched between the upper jig 28 and the protrusion 34A on the upper jig 28 side, so that a protrusion 18C that is thinner toward one side in the second direction is formed on the positive electrode side tab film 18. The boundary between this protrusion 18C and the excess parts of the first film 26 and the third film 36 on one side in the second direction from the protrusion 18C is melted by the heat of the hot press 42 and becomes cut or thinned.

[0055] Similarly, by sandwiching the first film 26 and the fourth film 40 between the upper jig 28 and the protrusion 38A on the upper jig 28 side, a protrusion 18C that is thinner toward the other side in the second direction is formed on the positive electrode side tab film 18. The boundary between this protrusion 18C and the excess parts of the first film 26 and the fourth film 40 on the other side in the second direction from the protrusion 18C is melted by the heat of the hot press 42 and becomes cut or thinned.

[0056] At this time, the second film 30 and the third film 36 are sandwiched between the lower jig 32 and the protrusion 34A on the lower jig 32 side, so that a protrusion 18C that is thinner toward one side in the second direction is formed on the positive electrode side tab film 18. The boundary between this protrusion 18C and the excess parts of the second film 30 and the third film 36 on one side in the second direction from the protrusion 18C is melted by the heat of the hot press 42 and becomes cut or thinned.

[0057] Similarly, by sandwiching the second film 30 and the fourth film 40 between the lower jig 32 and the protrusion 38A on the lower jig 32 side, a protrusion 18C that is thinner toward the other side in the second direction is formed on the positive electrode side tab film 18. The boundary between this protrusion 18C and the excess parts of the second film 30 and the fourth film 40 on the other side in the second direction from the protrusion 18C is melted by the heat of the hot press 42 and becomes cut or thinned.

[0058] Next, in the fourth step shown in Figure 4(D), the upper jig 28, the lower jig 32, the first horizontal jig 34, and the second horizontal jig 38 are removed, and the excess portions of the first film 26, the second film 30, the third film 36, and the fourth film 40 are removed from the positive electrode side tab film 18.

[0059] 6(A), the laminate sheet 24 is placed on the lower jig 44. Specifically, with one end 24B of the laminate sheet 24 placed on the upper surface of the lower jig 44, approximately half of the laminate sheet 24 is pressed into a recess 44A provided in the lower jig 44.

[0060] 6(B), a composite 46 in which the electrode body 12, electrolyte layer, positive electrode side current collector terminal 14, negative electrode side current collector terminal 16, positive electrode side tab film 18, and negative electrode side tab film 20 are integrated is placed in the recess 44A so that the composite 46 is on the upper side of the laminate sheet 24. Then, an upper jig 47 is placed on the lower jig 44 in a state in which approximately half of the laminate sheet 24 covers the upper side of the composite 46 and the other end 24C of the laminate sheet 24 is on the upper side of one end 24B.

[0061] Next, in a third step shown in FIG. 6(C), the laminate sheet 24 is pressed against the composite body 46 in the second direction by a clamp 48.

[0062] Next, in the fourth step shown in Figure 6(D), the laminate sheet 24 is pressed toward the composite 46 from the upper side in the third direction and the lower side in the third direction at both ends of the composite 46 in the first direction using heat bars 50, thereby welding the laminate sheet 24 to the composite 46.

[0063] 1, at one end side in the first direction of the composite body 46, the protrusion 18C of the positive electrode side tab film 18 enters the corner 24A of the laminate sheet 24 from the positive electrode side current collector terminal 14 side. This is also true between the negative electrode side tab film 20 and the laminate sheet 24. Therefore, in this embodiment, it is possible to prevent gaps from being generated between the corner 24A of the folded laminate sheet 24 and the positive electrode side tab film 18 and the negative electrode side tab film 20.

[0064] As described above, in this embodiment, communication between the inside and outside of the battery 10 can be prevented.

[0065] <Supplementary explanation of the above embodiment> (1) In the above-described embodiment, the protrusion of the tab film protrudes in the second direction from the corner provided at the end of the base portion of the current collector terminal in the second direction. However, depending on the specifications of the battery 10, the protrusion of the tab film may be configured to protrude in the third direction.

[0066] (2) In the above-described embodiment, four protrusions are provided for one tab film, but the configuration of the tab film is not limited to this. For example, if the laminate sheet is curved at a location where the corners of the base portion of the current collector terminal at the end in the second direction are rounded, a configuration may be adopted in which no protrusions are provided at the corners of the tab film corresponding to these locations. [Explanation of symbols]

[0067] 10 batteries 14 Positive collector terminal (collector terminal) 14A contact part 14B base part 14B1 Corner 16 Negative electrode collector terminal (collector terminal) 16A contact part 16B base part 18 Positive electrode tab film (tab film) 18C protrusion 20 Negative electrode tab film (tab film) 24 Laminated Sheet 26 First Film 28 Upper jig 30 Second Film 32 Lower jig 34 1st horizontal jig 34A Protrusion 36 Third Film 38 2nd horizontal jig 38A Protrusion 40 Fourth Film 42 Hot Press

Claims

1. An electrode body; a laminate sheet wound around the electrode body, extending away from the electrode body, and having a welded portion at which ends are welded together; a side surface component disposed on one side surface of the electrode body in the first direction; Equipped with the laminate sheet covers the electrode body and the surface of the side surface constituent portion in the thickness direction of the electrode body and one side in a second direction perpendicular to the first direction, a protrusion protruding from a corner provided at an end portion on one side in the second direction of the side surface constituent portion, the welded portion is disposed on one side of the side surface constituent portion in the second direction, the protrusions are inserted between the ends of the laminate sheets and joined to the laminate sheets, One of the ends of the laminate sheet is curved at the starting point where it bends from the side surface. battery.

2. The laminate sheet is cylindrical and has an opening, and the electrode body is housed inside the opening. the side surface constituent portion includes a base portion disposed on one side of the electrode body in a first direction, and a tab film welded to a periphery of the base portion, The tab film is welded to the laminate sheet, thereby sealing the electrode body within the laminate sheet. The battery of claim 1 .

3. The protrusion has a flat surface on one side in the thickness direction and a curved surface on the other side in the thickness direction. The battery of claim 1 .

Images