Method for manufacturing a battery cell

Abstract

A method of manufacturing a battery cell includes molding a resin sheet into a resin layer. The resin sheet includes an end face, a first side face, and a second side face. In a configuration state, the end face faces a first direction along a planar direction of an inner surface. The first side face faces a second direction perpendicular to the first direction and also along the planar direction. The first side face extends from the end face in a third direction that is opposite to the first direction. The second side face faces a fourth direction that is opposite to the second direction. The second side face extends from the end face in the third direction. A dimension between the first side face and the second side face decreases as it moves away from the end face.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a battery cell. Background Technology

[0002] Japanese Unexamined Patent Application Publication No. 2020-113496 (JP 2020-113496 A) discloses an all-solid-state battery cell in which an electrode stack is encapsulated within an outer encapsulation material. A first heat transfer material is disposed on the inside of the outer encapsulation material to contact the electrode stack and the outer encapsulation. Summary of the Invention

[0003] When a component is disposed on the inner surface of the outer casing as in the prior art, the adhesive strength between the component and the outer casing is preferably high. When the component is a resin layer, it is difficult to improve the adhesion between the outer casing and the resin layer while simultaneously disposing the resin layer inside the outer casing.

[0004] This disclosure was made in view of the above-mentioned problems, and its purpose is to provide a method for manufacturing a battery cell that can improve the adhesive strength between the outer casing and the resin layer.

[0005] According to one aspect of the present disclosure, a method for manufacturing a battery cell includes an outer casing comprising a first wall portion, a resin layer, and an electrode assembly. The method includes: disposing a resin sheet on the inner surface of the first wall portion; molding the resin sheet into a resin layer by compressing the resin sheet disposed on the inner surface toward the inner surface; and disposing the electrode assembly on the side of the resin layer opposite to the first wall portion. The resin sheet includes an end face, a first side face, and a second side face. In a disposed state where the resin sheet is disposed on the inner surface, the end face faces a first direction along a plane of the inner surface. In the disposed state, the first side face faces a second direction perpendicular to the first direction and also along a plane. In the disposed state, the first side face extends from the end face along a third direction opposite to the first direction. In the disposed state, the second side face faces a fourth direction opposite to the second direction. In the disposed state, the second side face extends from the end face along a third direction. The dimension between the first side face and the second side face decreases with distance from the end face.

[0006] According to this disclosure, the adhesive strength between the outer casing and the resin layer can be improved. Attached Figure Description

[0007] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals denote like elements, and wherein: Figure 1A is a diagram illustrating a battery cell manufactured using a method according to an embodiment of the present disclosure; Figure 1B is a diagram illustrating a battery cell manufactured using a method according to an embodiment of the present disclosure; Figure 1C is a diagram illustrating a battery cell manufactured using a method according to an embodiment of the present disclosure; Figure 2 is a flowchart illustrating a method for manufacturing a battery cell according to an embodiment of the present disclosure; Figure 3A is a diagram showing the state immediately after the resin sheet is disposed on the inner surface of the first wall portion; Figure 3B is a diagram showing the state immediately after the resin sheet is disposed on the inner surface of the first wall portion; Figure 4A shows the state immediately following the compression of the resin sheet to form a resin layer; Figure 4B shows the state immediately following the compression of the resin sheet to form a resin layer; Figure 5A is a diagram showing the state of the comparative example immediately after the resin component is disposed on the inner surface of the first wall portion; Figure 5B is a diagram showing the state of the comparative example immediately after the resin component is disposed on the inner surface of the first wall portion; Figure 6A is a diagram showing the state of the comparative example immediately after the resin component was compressed; Figure 6B is a diagram showing the state of the comparative example immediately after the resin component has been compressed. Detailed Implementation

[0008] The following description, with reference to the accompanying drawings, illustrates a method for manufacturing a battery cell according to an embodiment of the present disclosure. The same reference numerals in the drawings denote the same or equivalent parts, and descriptions of these parts will not be repeated.

[0009] First, a battery cell manufactured using the method according to embodiments of the present disclosure will be described. Figures 1A, 1B, and 1C are diagrams illustrating a battery cell manufactured using the method according to embodiments of the present disclosure. Figure 1A is a perspective view of the battery cell. Figure 1B is a partial cross-sectional view of the battery cell viewed from the direction of the arrow along line IB-IB in Figure 1A. Figure 1C is an exploded perspective view of the battery cell.

[0010] As shown in Figures 1A, 1B, and 1C, a battery cell 1 manufactured using the method according to embodiments of the present disclosure includes an outer casing 100, a resin layer 200, and an electrode assembly 300. The battery cell 1 can be a secondary battery such as a lithium-ion secondary battery or a nickel-metal hydride battery. The battery cell 1 can also be a solid-state battery.

[0011] The outer casing 100 includes a first wall portion 110, a second wall portion 120, a third wall portion 130, a fourth wall portion 140, a first cover portion 150, and a second cover portion 160. Figures 1A, 1B, 1C, and Figures 3A and 3B described below... Figure 4A In Figure 4B, directions "D1" to "D6" are indicated with the first wall portion 110 as the reference. "D1" represents the first direction, "D2" represents the second direction, "D3" represents the third direction, "D4" represents the fourth direction, "D5" represents the fifth direction, and "D6" represents the sixth direction. The second direction is orthogonal to the first direction. The third direction is opposite to the first direction. The fourth direction is opposite to the second direction. The fifth direction is orthogonal to both the first and second directions. The sixth direction is opposite to the fifth direction.

[0012] The first wall portion 110 has a plate-like shape. The first wall portion 110 includes an inner surface 111. The planar direction of the inner surface 111 is along both the first direction and the second direction. The inner surface 111 faces the fifth direction. Viewed from the fifth direction, the inner surface 111 has a rectangular shape. The inner surface 111 has a long side parallel to the first direction and a short side parallel to the second direction.

[0013] The second wall portion 120 has a plate-like shape. The second wall portion 120 extends from the first wall portion 110 along a fifth direction. The second wall portion 120 extends parallel to the first direction. Viewed from a second direction, the second wall portion 120 has a rectangular shape.

[0014] The third wall portion 130 has a plate-like shape. The third wall portion 130 extends from the first wall portion 110 along a fifth direction. The third wall portion 130 extends parallel to the first direction. Viewed from a fourth direction, the third wall portion 130 has a rectangular shape. Viewed from a fifth direction, the inner surface 111 of the first wall portion 110 is located between the second wall portion 120 and the third wall portion 130.

[0015] The fourth wall portion 140 has a plate-like shape. The fourth wall portion 140 connects the end of the second wall portion 120 on the fifth direction side with the end of the third wall portion 130 on the fifth direction side. The fourth wall portion 140 extends parallel to the first wall portion 110.

[0016] The first wall portion 110, the second wall portion 120, the third wall portion 130, and the fourth wall portion 140 are made of a single material, specifically a metal such as aluminum.

[0017] The first cover portion 150 is fixed to an open end of a generally rectangular cylindrical body formed by the first wall portion 110, the second wall portion 120, the third wall portion 130, and the fourth wall portion 140. The first cover portion 150 can be fixed to the open end by welding. The first cover portion 150 is provided with a first external terminal 171 and a second external terminal 172.

[0018] The second cover 160 is fixed to another open end of the generally rectangular cylindrical body formed by the first wall portion 110, the second wall portion 120, the third wall portion 130, and the fourth wall portion 140. The second cover 160 can be fixed to this open end by welding. The first external terminal 171 and the second external terminal 172 can also be provided on the second cover 160.

[0019] A resin layer 200 is disposed on the inner surface 111 of the first wall portion 110. The resin layer 200 is configured to contact both the second wall portion 120 and the third wall portion 130. The resin layer 200 includes a layer surface 210. The layer surface 210 faces a fifth direction. The layer surface 210 extends parallel to the plane of the inner surface 111.

[0020] The resin layer 200 is electrically insulating. The resin layer 200 can be a component for transferring heat from the electrode assembly 300 toward the first wall portion 110.

[0021] Electrode assembly 300 is also referred to as a battery element. In electrode assembly 300, a positive electrode and a negative electrode are stacked with a separator (neither shown). These layers are stacked in a second direction, but may alternatively be stacked in a fifth direction. Electrode assembly 300 may include a solid electrolyte instead of the separator. One of a first external terminal 171 and a second external terminal 172 is electrically connected to the positive electrode, and the other is electrically connected to the negative electrode. Electrode assembly 300 is housed within outer casing 100. Electrode assembly 300 may be in contact with resin layer 200.

[0022] Next, a method for manufacturing a battery cell 1 according to an embodiment of the present disclosure will be described. FIG2 is a flowchart illustrating a method for manufacturing a battery cell according to an embodiment of the present disclosure. As shown in FIG2, a method for manufacturing a battery cell according to an embodiment of the present disclosure includes a step S1 of configuring a resin sheet, a step S2 of forming a resin layer, a step S3 of configuring an electrode assembly, and a step S4 of fixing a first cover and a second cover.

[0023] Figures 3A and 3B show the state immediately after the resin sheet is disposed on the inner surface of the first wall portion. Figure 3A is a perspective view viewed from the first direction side, and Figure 3B is a plan view of the first wall portion 110 viewed from the inner surface 111 side.

[0024] As shown in Figures 3A and 3B, in step S1, the resin sheet 500 is disposed on the inner surface 111 of the first wall portion 110. It should be noted that in step S1, the first wall portion 110, the second wall portion 120, the third wall portion 130, and the fourth wall portion 140 are in the state before the first cover portion 150 and the second cover portion 160 are fixed.

[0025] The resin sheet 500 is electrically insulating. The resin sheet 500 includes an end face 510, a first side face 520, a second side face 530, and a pressure-bearing surface 540.

[0026] With the resin sheet 500 disposed on the inner surface 111, the end face 510 faces the first direction. The end face 510 extends substantially parallel to the second direction. The end face 510 also extends substantially parallel to the fifth direction.

[0027] In the configured state, the first side surface 520 faces the second direction. In the configured state, the first side surface 520 extends from the edge of the end face 510 in the second direction along a third direction. In the configured state, the first side surface 520 extends away from the second wall portion 120 as it moves away along the third direction.

[0028] In the configured state, the second side surface 530 faces the fourth direction. In the configured state, the second side surface 530 extends along the third direction from the edge of the end face 510 on the fourth direction side. In the configured state, the second side surface 530 extends away from the third wall portion 130 as it moves away along the third direction. The dimension L between the first side surface 520 and the second side surface 530 decreases as it moves away from the end face 510.

[0029] In the configured state, the pressure surface 540 faces the fifth direction. In the configured state, the pressure surface 540 extends parallel to the plane direction.

[0030] In step S2, the resin sheet 500 disposed on the inner surface 111 is compressed toward the inner surface 111, thereby molding the resin sheet 500 into a resin layer 200. Figures 4A and 4B are diagrams showing the state immediately after the resin sheet is compressed to form the resin layer. Figure 4A is a perspective view viewed from the first direction side, and Figure 4B is a plan view of the first wall portion 110 viewed from the inner surface 111 side.

[0031] As shown in Figures 3A and 3B, the resin sheet 500 is configured to be spaced apart from both the second wall portion 120 and the third wall portion 130. However, as shown in Figures 4A and 4B, the resin layer 200 is formed to contact both the second wall portion 120 and the third wall portion 130. The resin sheet 500 is compressed to form the resin layer 200, such that the thickness of the resin layer 200 in the fifth direction is at least 0.6 times and less than 0.8 times the thickness of the resin sheet 500 in the fifth direction in its configured state.

[0032] In step S3, the electrode assembly 300 is disposed on the side of the resin layer 200 opposite to the first wall portion 110 (see Figures 1A, 1B, and 1C). More specifically, the electrode assembly 300 is disposed surrounded by the resin layer 200, the second wall portion 120, the third wall portion 130, and the fourth wall portion 140.

[0033] In step S4, the first cover 150 and the second cover 160 are fixed to the first wall 110, the second wall 120, the third wall 130, and the fourth wall 140. As a result, the electrode assembly 300 is housed within the outer casing 100, and the outer casing 100 is sealed.

[0034] Here, a method for manufacturing a battery cell according to a comparative example will be described. The only difference between the method for manufacturing a battery cell according to the comparative example and that of this embodiment is that a resin component is provided instead of a resin sheet.

[0035] Figures 5A and 5B are diagrams showing the state of the comparative example immediately after the resin member is disposed on the inner surface of the first wall portion. Figure 5A is a perspective view viewed from the first direction side, and Figure 5B is a plan view of the first wall portion 110 viewed from the inner surface side.

[0036] As shown in Figures 5A and 5B, the dimension between the first side 920 and the second side 930 of the resin component 900 remains constant along the third direction. Furthermore, the first side 920 extends parallel to the second wall portion 120, and the second side 930 extends parallel to the third wall portion 130.

[0037] Figures 6A and 6B show the state of the comparative example immediately after the resin component has been compressed. Figure 6A Figure 6B is a perspective view viewed from the first direction side, and Figure 6A is a plan view of the first wall portion 110 viewed from the inner surface 111 side.

[0038] As shown in Figures 6A and 6B, the expansion amount of the first side surface 920X in the second direction is greater as it moves away from the end face 910X, and the expansion amount of the second side surface 930X in the fourth direction is greater. Therefore, in the compressed resin component 900X, the portions 901X and 902X that are away from the end face 910X and contact the second wall portion 120 and the third wall portion 130, respectively, bulge upwards in the fifth direction. A gap is also formed between the second wall portion 120 and the region 921X near the end face 910X of the first side surface 920X. Furthermore, a gap is formed between the third wall portion 130 and the region 931X near the end face 910X of the second side surface 930X.

[0039] On the other hand, the manufacturing method of the battery cell 1 according to an embodiment of the present disclosure includes a method for manufacturing a battery cell 1 comprising an outer casing 100 including a first wall portion 110, a resin layer 200, and an electrode assembly 300. The method includes: disposing a resin sheet 500 on the inner surface 111 of the first wall portion 110; compressing the resin sheet 500 disposed on the inner surface 111 toward the inner surface 111 to form the resin sheet 500 into a resin layer 200; and disposing the electrode assembly 300 on the side of the resin layer 200 opposite to the first wall portion 110. The resin sheet 500 includes an end face 510, a first side face 520, and a second side face 530. In the configuration state where the resin sheet 500 is disposed on the inner surface 111, the end face 510 faces a first direction along the planar direction of the inner surface 111. In the configuration state, the first side face 520 faces a second direction perpendicular to the first direction and also along the planar direction. In the configured state, the first side 520 extends from the end face 510 along a third direction opposite to the first direction. In the configured state, the second side 530 faces a fourth direction opposite to the second direction. In the configured state, the second side 530 extends from the end face 510 along a third direction. The dimension L between the first side 520 and the second side 530 decreases as it moves away from the end face 510.

[0040] When the resin sheet 500 is compressed toward the inner surface 111, the expansion of the first side surface 520 in the second direction is greater as it moves away from the end face 510, and the expansion of the second side surface 530 in the fourth direction is greater (refer to the comparative example). At this time, as described above, the dimension L between the first side surface 520 and the second side surface 530 is pre-decreased as it moves away from the end face 510, thereby making the width of the molded resin layer 200 in the second (fourth) direction relatively uniform. As a result, a relatively uniform pressure can be applied to the resin layer 200 (resin sheet 500), thereby enabling the resin layer 200 to be in close contact with the first wall portion 110. Therefore, the adhesive strength between the outer casing 100 and the resin layer 200 can be improved.

[0041] In this embodiment, the outer casing 100 also includes a second wall portion 120 and a third wall portion 130. The second wall portion 120 extends from the first wall portion 110 along a fifth direction, which is the direction in which the inner surface 111 faces. The second wall portion 120 extends parallel to the first direction. The third wall portion 130 extends from the first wall portion 110 along the fifth direction. The third wall portion 130 extends parallel to the first direction. Viewed from the fifth direction, the inner surface 111 is located between the second wall portion 120 and the third wall portion 130. The resin layer 200 is molded to contact both the second wall portion 120 and the third wall portion 130.

[0042] Even when the resin layer 200 is molded to contact both the second wall portion 120 and the third wall portion 130 as described above, in this embodiment, the dimension L between the first side surface 520 and the second side surface 530 decreases as it moves away from the end face 510. This can suppress the molded resin layer 200 from bulging upwards near the second wall portion 120 and the third wall portion 130 away from the end face 510 (see Comparative Example). Furthermore, damage to the resin layer 200 or the outer casing 100 caused by applying local pressure to the bulging portion of the resin layer 200 can be suppressed. Moreover, even with the second wall portion 120 and the third wall portion 130 present, a relatively uniform pressure can be applied to the resin layer 200 (resin sheet 500), thereby enabling the resin layer 200 to be in close contact with the first wall portion 110.

[0043] Furthermore, in this embodiment, in the configured state, the first side 520 extends away from the second wall portion 120 as it moves away in a third direction. In the configured state, the second side 530 extends away from the third wall portion 130 as it moves away in a third direction.

[0044] According to the above configuration, when the resin sheet 500 is compressed, the first side surface 520 expands more in the second direction and the second side surface 530 expands more in the fourth direction as it moves away from the end face 510. This allows the resin sheet 500 to be molded into a shape consistent with the second wall portion 120 and the third wall portion 130. Furthermore, a relatively uniform pressure can be applied to the resin layer 200 (resin sheet 500), thereby enabling the resin sheet 500 to be in close contact with the second wall portion 120 and the third wall portion 130.

[0045] In this embodiment, the resin sheet 500 further includes a pressure-receiving surface 540. In the configured state, the pressure-receiving surface 540 faces the fifth direction. In the configured state, the pressure-receiving surface 540 extends parallel to the planar direction. The resin layer 200 includes a layer surface 210 facing the fifth direction. The layer surface 210 extends parallel to the planar direction.

[0046] According to the above configuration, since the first side 520 and the second side 530 have the above configuration, even when the resin sheet 500 has a relatively simple shape in which the pressure surface 540 extends parallel to the above-mentioned planar direction, the resin layer 200 can be easily molded into a shape in which the layer surface 210 extends parallel to the above-mentioned planar direction.

[0047] In addition, in this embodiment, the thickness of the resin layer 200 in the fifth direction is more than 0.6 times and less than 0.8 times the thickness of the resin sheet 500 in the fifth direction in the configured state.

[0048] According to the above configuration, the resin layer 200 can be molded under relatively low pressure without compressing the resin sheet 500 to less than half.

[0049] In the description of the above embodiments, the configurations that can be combined can be combined with each other.

[0050] The embodiments disclosed herein should be considered exemplary and not restrictive in all respects. The scope of this disclosure is defined by the claims, not by the foregoing description, and is intended to include all modifications equivalent in meaning and scope to the claims.

Claims

1. A method for manufacturing a battery cell, the battery cell comprising an outer casing including a first wall portion, a resin layer, and an electrode assembly, the manufacturing method comprising: A resin sheet is disposed on the inner surface of the first wall portion; The resin sheet disposed on the inner surface is compressed toward the inner surface to form the resin layer; as well as The electrode assembly is positioned on the side of the resin layer opposite to the first wall portion, wherein The resin sheet includes an end face, a first side face, and a second side face. With the resin sheet disposed on the inner surface, the end face faces a first direction along the plane of the inner surface. In this configuration state, the first side faces a second direction that is perpendicular to the first direction and also along the plane direction. In the configured state, the first side extends from the end face along a third direction that is opposite to the first direction. In the configured state, the second side faces a fourth direction, which is opposite to the second direction. In the configured state, the second side extends from the end face along the third direction, and The dimension between the first side and the second side decreases as it moves away from the end face.

2. The manufacturing method according to claim 1, wherein... The outer casing also includes a second wall portion and a third wall portion. The second wall portion extends from the first wall portion along a fifth direction, which is the direction in which the inner surface faces. The second wall portion extends parallel to the first direction. The third wall portion extends from the first wall portion along the fifth direction. The third wall portion extends parallel to the first direction. Viewed from the fifth direction, the inner surface is located between the second wall portion and the third wall portion, and The resin layer is molded to contact both the second wall portion and the third wall portion.

3. The manufacturing method according to claim 2, wherein... In the configured state, the first side extends away from the second wall portion as it moves away along the third direction, and In the configured state, the second side extends away from the third wall portion as it moves away along the third direction.

4. The manufacturing method according to claim 2 or 3, wherein The resin sheet also includes a pressure-receiving surface. In the configured state, the pressure-bearing surface faces the fifth direction. In the configured state, the pressure-bearing surface extends parallel to the plane direction. The resin layer includes a layer surface facing the fifth direction, and The surface of the layer extends parallel to the plane.

5. The manufacturing method according to claim 4, wherein, In the configured state, the thickness of the resin layer in the fifth direction is more than 0.6 times to less than 0.8 times the thickness of the resin sheet in the fifth direction.

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