Battery cell and manufacturing method thereof

Abstract

To provide a battery cell which reduces the number of components and the number of assembling steps, and a method for manufacturing the same.SOLUTION: A battery cell includes: an electrode body which includes a positive electrode plate and a negative electrode plate; a case body which has an opening, and stores the electrode body; a sealing plate which has a terminal part insertion hole, and seals the opening of the case body; a terminal part which penetrates into the terminal part insertion hole of the sealing plate; a current collector which is stored in the case body together with the electrode body, and is electrically connected to the positive electrode plate or the negative electrode plate; and a resin insulator which includes a first portion for insulating the terminal part and the sealing plate outside the case body, a second portion for insulating the current collector and the sealing plate inside the case body, and a third portion which is brought into contact with the upper end face of the electrode body. The first portion, the second portion and the third portion of the resin insulator are integrally molded.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present technology relates to a battery cell and a method for manufacturing the same. [Background technology]

[0002] In a battery cell, it has been a common practice to provide an insulator between a plurality of conductive members in order to electrically insulate the plurality of conductive parts from one another, as shown in Patent Document 1, for example.

[0003] Patent Document 2 describes roughening part of the surface of the lid of the battery case and the electrode terminal of the battery cell to enhance the anchor effect and improve the bonding strength with the insulator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Chinese Utility Model Patent No. 206742372 [Patent Document 2] Patent Publication No. 2021-086813 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for reducing the number of parts in a battery cell and the number of steps required to assemble each part in the manufacturing process. From the above perspective, conventional battery cells and manufacturing methods thereof cannot necessarily be said to have a sufficient configuration.

[0006] An object of the present technology is to provide a battery cell with a reduced number of parts and assembly steps, and a manufacturing method thereof. [Means for solving the problem]

[0007] The present technology provides the following battery cell and method for manufacturing the same.

[0008] [1] A battery cell comprising: an electrode assembly including a positive electrode plate and a negative electrode plate; a case body having an opening and housing the electrode assembly; a sealing plate having a terminal insertion hole and sealing the opening of the case body; a terminal that passes through the terminal insertion hole in the sealing plate; a current collector housed in the case body together with the electrode assembly and electrically connected to the positive electrode plate or the negative electrode plate; and a resin insulator including a first portion that insulates the terminal portion from the sealing plate outside the case body, a second portion that insulates the current collector from the sealing plate inside the case body, and a third portion that abuts against the upper end surface of the electrode assembly, wherein the first portion, second portion, and third portion of the resin insulator are integrally molded.

[0009] [2] The battery cell according to [1], wherein the terminal portion and the sealing plate each have a contact surface that comes into contact with the resin insulator, and at least a portion of the contact surface of at least one of the terminal portion and the sealing plate is roughened.

[0010] [3] The battery cell according to [1] or [2], wherein the sealing plate has a generally rectangular shape with short sides along a first direction and long sides along a second direction perpendicular to the first direction, and the third portion of the resin insulator abuts against the upper end surface of the electrode body at a first position and a second position spaced apart from each other along the second direction.

[0011] [4] The battery cell according to [3], wherein the third portion of the resin insulator abuts against the upper end surface of the electrode body at a third position located between the first position and the second position, in addition to the first position and the second position.

[0012] [5] A method for manufacturing a battery cell, comprising the steps of: forming an electrode body including a positive electrode plate and a negative electrode plate; electrically connecting the positive electrode plate or the negative electrode plate to a current collector; attaching a terminal portion and a resin insulator to a sealing plate; connecting the current collector to the terminal portion; housing the electrode body in a case body having an opening; and sealing the opening of the case body with the sealing plate, wherein the resin insulator includes a first portion that insulates the terminal portion from the sealing plate outside the case body, a second portion that insulates the current collector from the sealing plate inside the case body, and a third portion that abuts against the upper end surface of the electrode body, and the first portion, second portion, and third portion of the resin insulator are integrally molded.

[0013] [6] The method for manufacturing a battery cell according to [5], further comprising a step of roughening at least a portion of the contact surface with the resin insulator of the terminal portion or the sealing plate. [Effects of the Invention]

[0014] According to this technology, by integrally molding a resin insulator including a first portion that insulates the terminal portion and the sealing plate outside the case body, a second portion that insulates the current collector and the sealing plate inside the case body, and a third portion that abuts the upper end surface of the electrode body, the number of parts and assembly man-hours can be reduced. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a perspective view showing a battery cell. [Figure 2] FIG. 2 is a plan view of a positive electrode plate that constitutes an electrode body. [Figure 3] FIG. 2 is a plan view of a negative electrode plate that constitutes an electrode body. [Figure 4] FIG. 2 is a plan view showing an electrode assembly consisting of a positive electrode plate and a negative electrode plate. [Figure 5] 3A and 3B are diagrams showing a connection structure between an electrode body, a positive electrode current collecting member, and a negative electrode current collecting member. [Figure 6] FIG. 2 is a cross-sectional view of a battery cell showing the structure of a terminal portion, a resin insulator, and a current collector. [Figure 7]FIG. 2 is a cross-sectional view of a sealing plate and a resin insulator in a battery cell. [Figure 8] FIG. 10 is a cross-sectional view (part 1) showing a modified example of the structure of the terminal portion and the resin insulator. [Figure 9] FIG. 10 is a cross-sectional view (part 2) showing a modified example of the structure of the terminal portion and the resin insulator. [Figure 10] FIG. 10 is a cross-sectional view (part 3) showing a modified example of the structure of the terminal portion and the resin insulator. [Figure 11] FIG. 10 is a cross-sectional view (part 4) showing a modified example of the structure of the terminal portion and the resin insulator. [Figure 12] FIG. 10 is a cross-sectional view (part 5) showing a modified example of the structure of the terminal portion and the resin insulator. [Figure 13] FIG. 10 is a cross-sectional view (part 6) showing a modified example of the structure of the terminal portion and the resin insulator. [Figure 14] FIG. 10 is a cross-sectional view (part 7) showing a modified example of the structure of the terminal portion and the resin insulator. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0017] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0018] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0019] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0020] In this specification, a "battery cell" can be installed in a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric vehicle (BEV), etc. However, the use of a "battery cell" is not limited to in-vehicle use.

[0021] 1 is a perspective view showing a battery cell 100. As shown in Fig. 1, the battery cell 100 has a rectangular shape. The battery cell 100 has an electrode terminal 110 (terminal portion), a housing 120 (external can), a gas release valve 130, and a rivet 140.

[0022] The electrode terminal 110 is formed on the housing 120. The electrode terminal 110 has a positive electrode terminal 111 and a negative electrode terminal 112 that are aligned along an X-axis direction (second direction) that is perpendicular to a Y-axis direction (first direction). The positive electrode terminal 111 and the negative electrode terminal 112 are spaced apart from each other in the X-axis direction.

[0023] The housing 120 has a rectangular parallelepiped shape and forms the exterior of the battery cell 100. The housing 120 includes a case body 120A that houses an electrode assembly and an electrolyte (not shown), and a sealing plate 120B that seals the opening of the case body 120A. The sealing plate 120B is joined to the case body 120A by welding.

[0024] The housing 120 has an upper surface 121, a lower surface 122, a first side surface 123, a second side surface 124, and two third side surfaces 125.

[0025] The upper surface 121 is a plane perpendicular to the Z-axis direction (third direction) that is perpendicular to the Y-axis direction and the X-axis direction. The electrode terminals 110 are disposed on the upper surface 121. The lower surface 122 faces the upper surface 121 along the Z-axis direction.

[0026] Each of the first side surface 123 and the second side surface 124 is made of a plane perpendicular to the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has the largest area among the multiple side surfaces of the housing 120. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction. Each of the first side surface 123 and the second side surface 124 has a rectangular shape when viewed in the Y-axis direction, with the X-axis direction being the longitudinal direction and the Z-axis direction being the lateral direction.

[0027] The multiple battery cells 100 are stacked such that the first side surfaces 123 and the second side surfaces 124 of the battery cells 100 adjacent to each other in the Y-axis direction face each other. As a result, the positive electrode terminals 111 and the negative electrode terminals 112 are arranged alternately in the Y-axis direction in which the multiple battery cells 100 are stacked.

[0028] The gas release valve 130 is provided on the top surface 121. When the temperature of the battery cell 100 rises (thermal runaway) and the internal pressure of the housing 120 exceeds a predetermined value due to gas generated inside the housing 120, the gas release valve 130 releases the gas to the outside of the housing 120.

[0029] The rivet 140 is attached to the sealing plate 120B of the housing 120. The rivet 140 seals an electrolyte injection hole, which will be described later.

[0030] FIG. 2 is a plan view of a positive electrode plate 200A constituting the electrode assembly 200. The positive electrode plate 200A has a main body 220A in which a positive electrode active material mixture layer containing a positive electrode active material (e.g., lithium nickel cobalt manganese composite oxide), a binder (e.g., polyvinylidene fluoride (PVdF)), and a conductive material (e.g., a carbon material) is formed on both sides of a rectangular positive electrode core made of aluminum foil. The positive electrode core protrudes from an edge of the main body, and this protruding positive electrode core constitutes a positive electrode tab 210A. A positive electrode protective layer 230A containing alumina particles, a binder, and a conductive material is provided on a portion of the positive electrode tab 210A adjacent to the main body 220A. The positive electrode protective layer 230A has a higher electrical resistance than the positive electrode active material mixture layer. The positive electrode active material mixture layer does not necessarily contain a conductive material. The positive electrode protective layer 230A is not necessarily provided.

[0031] 3 is a plan view of the negative electrode plate 200B that constitutes the electrode assembly 200. The negative electrode plate 200B has a main body 220B in which negative electrode active material mixture layers are formed on both sides of a rectangular negative electrode core made of copper foil. The negative electrode core protrudes from the end edge of the main body 220B, and this protruding negative electrode core constitutes the negative electrode tab 210B.

[0032] FIG. 4 is a plan view showing an electrode assembly 200 consisting of positive electrode plates 200A and negative electrode plates 200B. As shown in FIG. 5, the electrode assembly 200 is fabricated so that the positive electrode tabs 210A of the positive electrode plates 200A are stacked at one end, and the negative electrode tabs 210B of the negative electrode plates 200B are stacked. For example, about 50 positive electrode plates 200A and 50 negative electrode plates 200B are stacked. The positive electrode plates 200A and the negative electrode plates 200B are stacked alternately with rectangular polyolefin separators interposed between them. Note that a long separator may be used by folding it zigzag.

[0033] Fig. 5 is a diagram showing the connection structure between an electrode body 200 and a current collector 300 (positive electrode current collecting member and negative electrode current collecting member). As shown in Fig. 5, the electrode body 200 is composed of a first electrode body element 201 (first lamination group) and a second electrode body element 202 (second lamination group). Separators are also arranged on the outer surfaces of the first electrode body element 201 and the second electrode body element 202.

[0034] The multiple positive electrode tabs 210A of the first electrode body element 201 constitute a first positive electrode tab group 211A. The multiple negative electrode tabs 210B of the first electrode body element 201 constitute a first negative electrode tab group 211B. The multiple positive electrode tabs 210A of the second electrode body element 202 constitute a second positive electrode tab group 212A. The multiple negative electrode tabs 210B of the second electrode body element 202 constitute a second negative electrode tab group 212B.

[0035] A current collector 300 is disposed between the first electrode body element 201 and the second electrode body element 202. The first positive electrode tab group 211A and the second positive electrode tab group 212A are welded onto the positive electrode side current collector 300 to form a welded connection 213. The first negative electrode tab group 211B and the second negative electrode tab group 212B are welded onto the negative electrode side current collector 300 to form the welded connection 213. The welded connection 213 can be formed by, for example, ultrasonic welding, resistance welding, laser welding, or the like.

[0036] When manufacturing the battery cell 100, the electrode assembly 200 including the positive electrode plate 200A and the negative electrode plate 200B is formed, and the positive electrode plate 200A and the negative electrode plate 200B are electrically connected to the positive and negative electrode collectors 300, respectively. Next, the positive electrode terminal 111 and the negative electrode terminal 112 (terminal portions) attached to the sealing plate 120B are connected (for example, by crimping) to the positive and negative electrode collectors 300, respectively. In this state, the electrode assembly 200 is housed in the case body 120A, and the opening of the case body 120A is sealed with the sealing plate 120B.

[0037] Fig. 6 is a cross-sectional view of the battery cell 100. The structure around the negative electrode terminal 112 will be described using Fig. 6. Note that although the structure around the negative electrode terminal 112 will be described below, a similar structure can also be adopted around the positive electrode terminal 111.

[0038] 6, the negative electrode terminal 112 includes a terminal plate 112A and an external terminal 112B. The terminal plate 112A is provided to pass through a hole (terminal insertion hole) provided in the sealing plate 120B. The external terminal 112B is provided on the outside of the housing 120 and is coupled to the terminal plate 112A.

[0039] The current collector 300 is housed in the case body 120A together with the electrode body 200. The negative electrode side current collector 300 shown in Fig. 6 is electrically connected to the first negative electrode tab group 211B and the second negative electrode tab group 212B of the negative electrode plate 200B.

[0040] Resin insulator 400 includes a first portion 410, a second portion 420, and a third portion 430. Resin insulator 400 is formed by, for example, resin molding. In resin insulator 400, first portion 410, second portion 420, and third portion 430 are molded integrally.

[0041] The first portion 410 is located outside the case body 120A. The first portion 410 insulates the negative electrode terminal 112 (terminal portion) from the sealing plate 120B.

[0042] The second portion 420 is located inside the first portion and the case body 120A. The second portion 420 insulates the current collector 300 from the sealing plate 120B.

[0043] The third portion 430 is located inside the case body 120 A. The third portion 430 abuts against the upper end surface of the electrode body 200.

[0044] 7 is a cross-sectional view of the sealing plate 120B and the resin insulator 400 of the battery cell 100. As shown in Fig. 7, the third portion 430 of the resin insulator 400 includes a first boss portion 431, a second boss portion 432, and a third boss portion 433 that are spaced apart from one another along the X-axis direction.

[0045] First boss portion 431 and second boss portion 432 are provided at both ends of resin insulator 400 in the X-axis direction (first position and second position), respectively. Third boss portion 433 is provided at a midpoint in the X-axis direction (third position) different from the both ends. More specifically, third boss portion 433 is provided at the center of resin insulator 400 in the X-axis direction.

[0046] The first boss portion 431, the second boss portion 432, and the third boss portion 433 abut against the upper end surface of the electrode body 200 in the Z-axis direction.

[0047] The shape of resin insulator 400 is not limited to those shown in Figures 6 and 7. For example, the shape (position and number of boss portions, etc.) of third portion 430 in resin insulator 400 can be changed as appropriate. For example, first boss portion 431, second boss portion 432, and third boss portion 433 may be formed so that the base sides are thicker than the tip sides.

[0048] Next, modified examples of the structure of the negative electrode terminal 112 and the resin insulator 400 will be described with reference to FIGS.

[0049] 8 to 14, at least a part of the contact surface of electrode terminal 110 or sealing plate 120B with resin insulator 400 is roughened. The roughening can be performed by, for example, laser processing of the surface.

[0050] 8, roughened portion 112A1 is provided on a portion of the surface of terminal board 112A, and roughened portion 120B1 is provided on a portion of the surface of sealing plate 120B. Roughened portions 112A1 and 120B1 are provided so as to sandwich second portion 420 of resin insulator 400 therebetween.

[0051] 9 to 11, terminal board 112A and sealing plate 120B have roughened portion 120B1 only on a portion of the surface of sealing plate 120B. In the example of FIG. 9, roughened portion 120B1 is provided on the inner circumferential surface of the terminal insertion hole. In the example of FIG. 10, roughened portion 120B1 is provided only on a portion that contacts second portion 420 of resin insulator 400. In the example of FIG. 11, roughened portion 120B1 is provided in a U-shape extending from a portion that contacts first portion 410 of resin insulator 400 to a portion that contacts the inner circumferential surface of the terminal insertion hole and the second portion 420 of resin insulator 400.

[0052] 12 to 14, of terminal board 112A and sealing plate 120B, roughened portion 112A1 is provided only on a portion of the surface of terminal board 112A. In the example of FIG. 12, roughened portion 112A1 is provided on the outer peripheral surface of the portion inserted into the terminal insertion hole. In the example of FIG. 13, roughened portion 112A1 is provided only on the portion that contacts second portion 420 of resin insulator 400. In the example of FIG. 14, roughened portion 112A1 is provided in an L-shape extending from the outer peripheral surface of the portion inserted into the terminal insertion hole to the portion that contacts second portion 420 of resin insulator 400.

[0053] According to the battery cell 100 of this embodiment, a resin insulator including a first portion 410 that insulates the electrode terminal 110 and the sealing plate 120B outside the case body 120A, a second portion 420 that insulates the current collector 300 and the sealing plate 120B inside the case body 120A, and a third portion 430 that abuts the upper end surface of the electrode body 200 is integrally molded. This allows the resin insulator 400, which has conventionally been made up of a combination of multiple parts, to be constructed from a single part, thereby reducing the number of parts and the labor required to assemble the resin insulator 400.

[0054] Furthermore, if at least a portion of the contact surfaces of electrode terminal 110 and sealing plate 120B with resin insulator 400 is roughened, the anchor effect can improve the adhesion between electrode terminal 110 and sealing plate 120B and resin insulator 400.

[0055] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0056] 100 battery cell, 110 electrode terminal, 111 positive electrode terminal, 112 negative electrode terminal, 112A terminal plate, 112A1 roughened portion, 112B external terminal, 120 housing, 120A case body, 120B sealing plate, 120B1 roughened portion, 121 upper surface, 122 lower surface, 123 first side surface, 124 second side surface, 125 third side surface, 130 gas release valve, 140 rivet, 200 electrode body, 200A positive electrode plate, 200B negative electrode plate, 201 first electrode body element, 202 second electrode body element, 210A positive electrode tab, 210B negative electrode tab, 211A first positive electrode tab group, 211B first negative electrode tab group, 212A second positive electrode tab group, 212B Second negative electrode tab group, 213 welded connection portion, 220A, 220B main body portion, 230A positive electrode protective layer, 300 current collector, 400 resin insulator, 410 first portion, 420 second portion, 430 third portion, 431 first boss portion, 432 second boss portion, 433 third boss portion.

Claims

1. an electrode assembly including a positive electrode plate and a negative electrode plate; a case body having an opening and accommodating the electrode body; a sealing plate having a terminal insertion hole and sealing the opening of the case body; a terminal portion that passes through the terminal portion insertion hole of the sealing plate; a current collector housed in the case body together with the electrode assembly and electrically connected to the positive electrode plate or the negative electrode plate; a resin insulator including a first portion that contacts the terminal portion and the sealing plate outside the case body and insulates the terminal portion from the sealing plate, a second portion that insulates the current collector from the sealing plate inside the case body, and a third portion that abuts on an upper end surface of the electrode assembly, the first portion, the second portion, and the third portion of the resin insulator are integrally molded, the resin insulator and the current collector are spaced apart from each other.

2. the terminal portion and the sealing plate each have a contact surface that comes into contact with the resin insulator, The battery cell according to claim 1 , wherein at least a portion of the contact surface of at least one of the terminal portion and the sealing plate is roughened.

3. the sealing plate has a substantially rectangular shape including a short side along a first direction and a long side along a second direction perpendicular to the first direction, 3 . The battery cell according to claim 1 , wherein the third portion of the resin insulator abuts against the upper end surface of the electrode body at a first position and a second position that are spaced apart from each other along the second direction.

4. 4. The battery cell according to claim 3, wherein the third portion of the resin insulator abuts the upper end surface of the electrode body at a third position located between the first position and the second position, in addition to the first position and the second position.

5. forming an electrode assembly including a positive electrode plate and a negative electrode plate; a step of electrically connecting the positive electrode plate or the negative electrode plate to a current collector; a step of attaching a terminal portion and a resin insulator to a sealing plate; connecting the current collector and the terminal portion; a step of housing the electrode assembly in a case body having an opening; and sealing the opening of the case body with the sealing plate, the resin insulator includes a first portion that contacts the terminal portion and the sealing plate outside the case body and insulates the terminal portion from the sealing plate, a second portion that insulates the current collector from the sealing plate inside the case body, and a third portion that abuts on an upper end surface of the electrode assembly, the first portion, the second portion, and the third portion of the resin insulator are integrally molded, The resin insulator and the current collector are spaced apart.

6. The battery cell manufacturing method according to claim 5 , further comprising the step of roughening at least a portion of the contact surface of the terminal portion or the sealing plate with the resin insulator.

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