Power storage cell and method for manufacturing power storage cell

Abstract

A capacitor cell comprises an electrode body and a receiving case that accommodates the electrode body. The receiving case includes a first side wall, a second side wall arranged at a distance from the first side wall in an arrangement direction, and a main body connecting the first side wall and the second side wall. The main body has a first end wall and a second end wall arranged at a distance from the first end wall with the electrode body in between. An exhaust valve and a projection protruding toward the electrode body are formed on the first end wall.

Description

Technology Field

[0001] The present disclosure relates to a capacitor cell and a method for manufacturing a capacitor cell. Background Technology

[0002] Various types of capacitor cells for capacitor devices mounted in vehicles have been proposed. For example, Japanese Patent Publication No. 2000-067821 discloses a capacitor cell having a receiving case and an electrode body received in the receiving case. The receiving case has a first end wall, a second end wall, and a perimeter wall connecting the first end wall and the second end wall. The perimeter wall has a first side and a second side facing the first side with the electrode body in between. An exhaust valve is formed in the first end wall. A concave portion is formed in the first side and the second side. The concave portion prevents the electrode body from moving within the receiving case, thereby preventing damage to the electrode body. The problem to be solved

[0003] In the first side and second side of the capacitor cell disclosed in Japanese Patent Publication No. 2000-067821, a concave portion is formed. As a result, a space is created between the first side and the electrode body, and between the second side and the electrode body, respectively. The space created by the concave portion is a factor in the reduction of the energy density of the capacitor cell. In addition, it is preferable that there be a gap between the exhaust valve formed on the first end wall and the electrode body. This is to secure an exhaust path for gas generated within the receiving case. On the other hand, securing an exhaust path between the exhaust valve and the electrode body may accelerate the reduction of the energy density of the capacitor cell.

[0004] The present disclosure is made in consideration of the above-mentioned problems, and its purpose is to provide a capacitor cell capable of suppressing the movement of an electrode body within a receiving case and suppressing the reduction of energy density caused by the electrode body movement countermeasures, and a method for manufacturing the capacitor cell. means of solving the problem

[0005] A capacitor cell related to the present disclosure comprises an electrode body and a receiving case that accommodates the electrode body. The receiving case includes a first side wall, a second side wall arranged at a distance from the first side wall in an arrangement direction, and a main body connecting the first side wall and the second side wall. The main body has a first end wall and a second end wall arranged at a distance from the first end wall with the electrode body in between. An exhaust valve and a projection protruding toward the electrode body are formed on the first end wall.

[0006] The protrusion of the capacitor cell related to the present disclosure may be formed by the first end wall being formed in a concave shape.

[0007] The capacitor cell related to the present disclosure may additionally have an external terminal. The external terminal may be formed on at least one of the first side wall or the second side wall.

[0008] The capacitor cell related to the present disclosure may additionally be provided with an external terminal. The external terminal may be formed on the first end wall.

[0009] A capacitor cell related to the method of manufacturing a capacitor cell related to the present disclosure comprises an electrode body, a receiving case for receiving the electrode body, and an external terminal. The receiving case includes a first side wall, a second side wall arranged at a distance from the first side wall in an arrangement direction, and a main body connecting the first side wall and the second side wall. The main body has a first end wall and a second end wall arranged at a distance from the first end wall with the electrode body in between. An exhaust valve and a projection protruding toward the electrode body are formed on the first end wall. The external terminal has a first terminal formed on the first side wall and a second terminal formed on the second side wall. An electrode body unit is formed by the electrode body, the external terminal, the first side wall, and the second side wall. A method for manufacturing a capacitor cell comprises a process of preparing an electrode body unit, a process of inserting the electrode body unit into a main body, a process of joining each of the first side wall and the second side wall of the electrode body unit to the main body, and a process of forming a protrusion by pressing the first side wall. Effects of the invention

[0010] According to the capacitor cell related to the present disclosure, the movement of the electrode body within the receiving case is suppressed, and at the same time, the reduction of energy density due to the electrode body movement countermeasures can be suppressed. Brief explanation of the drawing

[0011] 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, and like reference numerals denote like elements. FIG. 1 is a schematic diagram of a vehicle equipped with a battery storage device according to an embodiment of the present disclosure; FIG. 2 is a schematic diagram of a capacitor having a capacitor cell in an embodiment of the present disclosure; FIG. 3 is an exploded perspective view of a capacitor device in an embodiment of the present disclosure; FIG. 4 is a perspective view of a capacitor cell in an embodiment of the present disclosure; FIG. 5 is a cross-sectional view of the capacitor cell shown in FIG. 4, viewed in the direction of the VV line arrow; FIG. 6 is a modified example of a capacitor cell in an embodiment of the present disclosure; and FIG. 7 is a flowchart illustrating a method for manufacturing a capacitor cell in an embodiment of the present disclosure. Specific details for implementing the invention

[0012] Hereinafter, embodiments and variations of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or substantial parts are denoted by the same reference numerals, and their descriptions are not repeated.

[0013] embodiments

[0014] FIG. 1 is a schematic diagram of a vehicle equipped with a battery storage device according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram of a battery storage device having a battery cell according to an embodiment of the present disclosure. In addition, the vertical direction (H) shown in FIG. 1 indicates the vertical direction of the vehicle (1). The width direction (W) indicates the width direction of the vehicle (1). The front-rear direction (D) indicates the front-rear direction of the vehicle (1). In addition, the width direction (W) is an example of the "arrangement direction" of the present disclosure.

[0015] The vehicle (1) is equipped with a vehicle body (2) and a battery storage device (3). The vehicle (1) includes, for example, a PHEV (Plug-in Hybrid Electric Vehicle), a BEV (Battery Electric Vehicle), or an FCEV (Fuel Cell Electric Vehicle). The battery storage device (3) is positioned below the bottom portion (2a) of the vehicle body (2).

[0016] FIG. 3 is an exploded perspective view of a capacitor device in the present embodiment. The capacitor device (3) is equipped with a storage case (4) and a capacitor stack (9).

[0017] The storage case (4) includes an upper cover (5) and a lower case (6). The storage case (4) forms a receiving space (V) defined by the upper cover (5) and the lower case (6).

[0018] The upper cover (5) is formed to cover the lower case (6), which is formed to open upward.

[0019] The lower case (6) includes a bottom wall (7) and a standing wall (8). The bottom wall (7) supports the capacitor stack (9) in the vertical direction (H). An opening (7a) is formed in the bottom wall (7). The opening (7a) is positioned opposite the exhaust valve (24a) described later. The standing wall (8) is formed to stand upward from the bottom wall (7) in the vertical direction (H).

[0020] The capacitor stack (9) is placed on the upper surface of the bottom wall (7) while being accommodated in the receiving space (V). The capacitor stack (9) is formed of a plurality of capacitor cells (10). The plurality of capacitor cells (10) are arranged in the front-rear direction (D). The capacitor cells (10) are formed in the shape of a rectangular body that is elongated in the width direction (W).

[0021] FIG. 4 is a perspective view of a capacitor cell in an embodiment of the present disclosure. The capacitor cell (10) is a so-called rectangular battery formed to extend in the width direction (W). The capacitor cell (10) may be a secondary battery configured to be rechargeable, such as a lithium-ion battery or a nickel-hydrogen battery. The capacitor cell (10) is equipped with a receiving case (20), an external terminal (30), and an electrode body (40).

[0022] The receiving case (20) is conductive. The receiving case (20) is made of a metal such as aluminum, for example. The receiving case (20) accommodates an electrode body (40). The receiving case (20) also accommodates an electrolyte not shown in FIG. 4. The receiving case (20) has a first side wall (21), a second side wall (22), and a main body (23). The first side wall (21) and the second side wall (22) are spaced apart in the width direction (W). The main body (23) connects the first side wall (21) and the second side wall (22). The main body (23) is formed normally. When viewed from the width direction (W) away from the main body (23), the main body (23) has an approximately rectangular shape. The first side wall (21) is attached to the edge portion of the main body (23). The second side wall (22) is attached to the outer edge portion of the main body (23).

[0023] The main body (23) has a first end wall (24) and a second end wall (25). The first end wall (24) and the second end wall (25) are spaced apart in the vertical direction (H) with the electrode body (40) in between. In an embodiment of the present disclosure, the first end wall (24) is located below the second end wall (25).

[0024] Figure 5 is a cross-sectional view of the capacitor cell shown in Figure 4, viewed in the direction of the VV line arrow.

[0025] In the first end wall (24), an exhaust valve (24a) and a projection (24b) are formed.

[0026] The exhaust valve (24a) is located at the center of the first end wall in the width direction (W). The exhaust valve (24a) is a known exhaust valve. For example, Japanese Patent Publication No. 2013-243075 discloses an exhaust valve (24a) having a general portion that is thinly processed compared to the first end wall (24). A concave groove for breaking is formed in the general portion of the exhaust valve (24a). By appropriately designing this concave groove, the exhaust valve (24a) is selectively opened by a slight increase in pressure inside the receiving case (20). The concave groove is formed, for example, by a die and a punch. When viewed from a plane in the vertical direction (H), the concave groove is formed in an elliptical or straight shape.

[0027] The protrusion (24b) is formed to protrude toward the electrode body (40). The protrusion (24b) is formed by the first end wall (24), which is a plate-shaped member, being formed in a concave shape toward the electrode body (40). In an embodiment of the present disclosure, two protrusions (24b) are formed in the first end wall (24), spaced apart in the width direction (W) with the exhaust valve (24a) in between. By forming the protrusion (24b) on the first end wall (24), a space (R) is formed between the first end wall (24) and the electrode body (40).

[0028] The external terminal (30) has a first terminal (31) and a second terminal (32). Each of the first terminal (31) and the second terminal (32) is electrically connected to an electrode body (40). In an embodiment of the present disclosure, the first terminal (31) is a positive terminal and the second terminal (32) is a negative terminal.

[0029] The first terminal (31) is formed on the first side wall (21). The first terminal (31) has a first conductive portion (31a) and a first protective portion (31b). A portion of the first conductive portion (31a) is located within the receiving case (20) and is in contact with the first tab (51) described later, and a portion of the first conductive portion (31a) is formed to be exposed from the receiving case (20). The first protective portion (31b) has electrical insulation properties. The first protective portion (31b) is located between the first conductive portion (31a) and the first side wall (21).

[0030] Likewise, the second terminal (32) is formed in the second side wall (22). The second terminal (32) has a second conductive portion (32a) and a second protective portion (32b). A portion of the second conductive portion (32a) is located within the receiving case (20) and is in contact with the second tab (52) described later, and a portion of the second conductive portion (32a) is formed to be exposed from the receiving case (20). The second protective portion (32b) has electrical insulation properties. The second protective portion (32b) is located between the second conductive portion (32a) and the second side wall (22).

[0031] The electrode body (40) is, for example, a wound electrode body. A wound electrode body is formed by winding a sheet group in which a positive electrode sheet, a separator, and a negative electrode sheet are stacked.

[0032] The electrode body (40) has a first cross section (40a), a second cross section (40b), and a periphery surface (40c). The first cross section (40a) and the second cross section (40b) are spaced apart in the width direction (W). The first cross section (40a) is opposite to the first side wall (21). The second cross section (40b) is opposite to the second side wall (22). The periphery surface (40c) connects the first cross section (40a) and the second cross section (40b).

[0033] The electrode body (40) additionally has a current collection tab (50). The current collection tab (50) has a first tab (51) and a second tab (52). The first tab (51) is formed to protrude from the first cross section (40a) toward the first side wall (21) in the width direction (W). The second tab (52) is formed to protrude from the second cross section (40b) toward the second side wall (22) in the width direction (W). The first tab (51) is electrically connected to an unillustrated positive electrode sheet of the electrode body (40). The second tab (52) is electrically connected to an unillustrated negative electrode sheet of the electrode body (40). The first tab (51) is electrically connected to a first conductive portion (31a). The second tap (52) is electrically connected to the second conductive part (32a).

[0034] The capacitor cell (10) additionally has an insulating film (60). The insulating film (60) has electrical insulating properties. The insulating film (60) is made of a film-like material. The insulating film (60) is disposed between the electrode body (40) and the receiving case (20). The insulating film (60) electrically insulates the receiving case (20) and the electrode body (40). The insulating film (60) includes a main insulating portion (61) and a cross-sectional insulating portion (62).

[0035] The main insulating portion (61) is positioned between the electrode body (40) and the main body (23). The cross-sectional insulating portion (62) is positioned between the electrode body (40) and the first side wall (21), and between the electrode body (40) and the second side wall (22). An opening is formed in the cross-sectional insulating portion (62) through which the current collection tap (50) passes.

[0036] A capacitor cell (10) related to an embodiment of the present disclosure has a receiving case (20) and an electrode body (40) received in the receiving case (20). The receiving case (20) has a first end wall (24). An exhaust valve (24a) and a projection (24b) are formed in the first end wall (24). The projection (24b) is formed to protrude toward the electrode body (40). By forming the projection (24b), a space (R) is formed between the first end wall (24) and the electrode body (40).

[0037] The protrusion (24b) of the capacitor cell (10) having such a configuration can prevent the electrode body (40) from moving within the receiving case (20). Additionally, it is preferable that a space is formed between the exhaust valve (24a) formed in the receiving case (20) and the electrode body (40) to secure an exhaust path for gas generated within the receiving case (20). Here, in the capacitor cell (10) of the present disclosure, the exhaust valve (24a) and the protrusion (24b) are formed on the first end wall (24). Thus, the space (R) created by the protrusion (24b) formed to prevent the movement of the electrode body (40) serves the purpose of securing an exhaust path. That is, compared to the case where the exhaust valve (24a) and the protrusion (24b) are formed on different walls, when the exhaust valve (24a) and the protrusion (24b) are formed on the same wall (e.g., the first end wall (24)), the decrease in energy density of the capacitor cell can be suppressed.

[0038] In an embodiment of the present disclosure, the protrusion (24b) is formed by the first end wall (24) being formed in a concave shape toward the electrode body (40). By pressing the electrode body (40) with the receiving case (20) without adding a new member to the capacitor cell (10), the decrease in energy density per unit of mass of the capacitor cell (10) can be suppressed.

[0039] Additionally, the protrusion (24b) does not need to be formed by the first end wall (24) being formed in a concave shape. For example, a buffer member may be disposed between the first end wall (24) and the electrode body (40). The buffer member may be, for example, an elastic body and may be formed to fill the space between the first end wall (24) and the electrode body (40).

[0040] In an embodiment of the present disclosure, the first end wall (24) having the exhaust valve (24a) formed therein is located below the second end wall (25) in the vertical direction (H). This prevents gas ejected from the exhaust valve (24a) from entering the cabin space of the vehicle (1).

[0041] In an embodiment of the present disclosure, an example was shown in which an external terminal (30) is formed on each of the first side wall (21) and the second side wall (22), but the present disclosure is not limited thereto.

[0042] For example, the external terminal (30) may be formed on at least one of the first sidewall (21) or the second sidewall (22). More specifically, a first tap (51) and a second tap (52) may be formed on the first cross-section (40a) of the electrode body (40). The first terminal (31) and the first tap (51) formed on the first sidewall (21) are electrically connected. Likewise, the second terminal (32) and the second tap (52) formed on the second sidewall (22) are electrically connected. By doing so, the space between the second sidewall (22) and the second cross-section (40b) of the electrode body (40) can be reduced, and the decrease in energy density of the capacitor cell (10) can be suppressed.

[0043] For example, as shown in FIG. 6, the external terminal (30) may be formed on the first end wall (24). More specifically, the first end (40a) of the electrode body (40) may face the first end wall (24). A first tap (51) and a second tap (52) may be formed on the first end (40a). The first terminal (31) and the second terminal (32) of the external terminal (30) may be formed on the first end wall (24). The first terminal (31) and the first tap (51) are electrically connected. The second terminal (32) and the second tap (52) are electrically connected. Thus, a current collecting tap (50) is placed in the space (R) created by the formation of the protrusion (24b). That is, the formation of space for placing the current collection tap (50) can be avoided, and the reduction of the energy density of the capacitor cell (10) can be suppressed. In addition, the first end wall (24) may be upward or downward in the vertical direction (H) compared to the second end wall (25).

[0044] Method for manufacturing a capacitor cell

[0045] Next, an example of a method for manufacturing a capacitor cell (10) will be described using FIG. 7. FIG. 7 is a flowchart related to the method for manufacturing a capacitor cell (10). As shown in FIG. 7, the method for manufacturing a capacitor cell (10) includes, in process order, a preparation process S1, an insertion process S2, a bonding process S3, and a pressurizing process S4. Details of the process will be described below.

[0046] Preparation process S1 is described. In preparation process S1, an electrode body unit (10a) and a main body part (23) are prepared. The electrode body unit (10a) shown in FIG. 5 is formed by a first side wall (21), a second side wall (22), an external terminal (30), and an electrode body (40) surrounded by an insulating film (60). The external terminal (30) has a first terminal (31) and a second terminal (32). The first terminal (31) is formed on the first side wall (21). The second terminal (32) is formed on the second side wall (22). In the first cross section (40a), the first terminal (31) and the electrode body (40) are electrically connected. In the second section (40b), the second terminal (32) and the electrode body (40) are electrically connected.

[0047] Taking Fig. 7 into consideration again, in the insertion process S2, the electrode unit (10a) is inserted into the main body part (23).

[0048] In the bonding process S3, the first sidewall (21) and the second sidewall (22) of the electrode body unit (10a) are each bonded to the main body part (23).

[0049] In the pressurization process S4, a portion of the first end wall (24) of the main body (23) is pressed toward the electrode body (40) to form a protrusion (24b) on the first end wall (24). Additionally, the bonding process S3 and the pressurization process S4 are performed in any order.

[0050] In an embodiment of the present disclosure, a pressurizing process S4 is performed after an insertion process S2. More specifically, after inserting the electrode unit (10a) into the main body (23), a protrusion (24b) is formed on the first end wall (24) of the main body (23). This allows the electrode unit (10a) to be smoothly inserted into the main body (23) during the insertion process S2.

[0051] Although embodiments of the present disclosure have been described above, the embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The technical scope of the present disclosure is defined by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Claims

Claim 1 A capacitor cell comprising an electrode body and a receiving case for receiving the electrode body, wherein the receiving case comprises a first side wall, a second side wall arranged at a distance from the first side wall in an arrangement direction, and a main body connecting the first side wall and the second side wall, wherein the main body comprises a first end wall and a second end wall arranged at a distance from the first end wall with the electrode body in between, and wherein the first end wall has an exhaust valve and a projection formed thereon protruding toward the electrode body. Claim 2 In claim 1, the protrusion is a capacitor cell formed by the first end wall being formed in a concave shape. Claim 3 A capacitor cell according to claim 1 or 2, further comprising an external terminal, wherein the external terminal is formed on at least one of the first side wall or the second side wall. Claim 4 In claim 1 or 2, an external terminal is additionally provided, said external terminal is a capacitor cell formed on the first end wall. Claim 5 A method for manufacturing a capacitor cell comprising an electrode body, a receiving case for receiving the electrode body, and an external terminal, wherein the receiving case comprises a first side wall, a second side wall arranged at a distance from the first side wall in an arrangement direction, and a main body connecting the first side wall and the second side wall, wherein the main body comprises a first end wall and a second end wall arranged at a distance from the first end wall with the electrode body in between, wherein the first end wall has an exhaust valve and a projection protruding toward the electrode body, and the external terminal comprises a first terminal formed on the first side wall and a second terminal formed on the second side wall, wherein an electrode body unit is formed by the electrode body, the external terminal, the first side wall, and the second side wall, and the method for manufacturing the capacitor cell comprises a process of preparing the electrode body unit, a process of inserting the electrode body unit into the main body, and the electrode body unit A method for manufacturing a capacitor cell, comprising a process of joining each of the first side wall and the second side wall to the main body, and a process of forming a protrusion by pressing the first side wall.

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