Power storage device and method for manufacturing the same

Abstract

To prevent damage to a sealing material and falling of an electrode terminal due to rising of an electrode terminal.SOLUTION: A case 10 of a power storage device 100 includes a sealing plate 14, an electrode terminal 20, and a sealing material 30. The electrode terminal 20 has a shaft portion 22 and a plate portion 24. The plate portion 24 includes a connection surface 24a exposed to the outside of the case, a back surface 24b on an opposite side of the connection surface 24a, and a side surface 24c continuous with the connection surface 24a and the back surface 24b. The sealing material 30 includes: a base portion 32 that covers a back surface 24b of the plate portion 24 and the sealing plate 14; a side surface protection portion 36 that is continuous with the base portion 32 and covers the side surface 24c of the plate portion 24; and a locking portion 39 that is continuous with an upper end of the side surface protection portion 36 and covers a peripheral portion 24a1 of the connection surface 24a. In the power storage device 100 having such a configuration, since rising of the electrode terminal 20 can be regulated by the locking portion 39 of the sealing material 30, it is possible to prevent the sealing material 30 from being damaged and the electrode terminal 20 from falling off.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device and a method for manufacturing an electricity storage device. [Background technology]

[0002] Power storage devices such as secondary batteries are used as power sources for various electrical appliances. These power storage devices include an electrode assembly and a case that houses the electrode assembly. The case includes, for example, a box-shaped case body with an opening and a sealing plate that closes the opening of the case body. The case also includes electrode terminals that are connected to external conductive parts (such as bus bars) and a sealant that insulates the electrode terminals from the case.

[0003] An example of this electricity storage device is disclosed in Japanese Patent Application Laid-Open No. 2016-058215. A through hole is formed in the lid main body (sealing plate) described in this document. A terminal portion (electrode terminal) is disposed through the through hole in the lid main body. A resin member (sealing material) seals the gap between the terminal portion and the lid main body and fixes the terminal portion to the lid main body. The terminal portion also includes an outer placement portion that is disposed on the outside of the lid main body. The resin member described in the above patent document covers the periphery of the outer placement portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-058215 Summary of the Invention [Problem to be solved by the invention]

[0005] Portable power sources such as power storage devices are often installed in mobile devices such as mobile terminals and vehicles. Vibrations caused by the movement of these mobile devices can cause stress to be applied to the electrode terminals of the power storage device. If a strong stress is applied in a direction that lifts the electrode terminals, it can damage the sealing material or cause the electrode terminals to come off. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, a method for manufacturing an electricity storage device (hereinafter, also simply referred to as "manufacturing method") having the following configuration is provided.

[0007] The electricity storage device disclosed herein includes an electrode assembly and a case that houses the electrode assembly. The case includes a case part with a through hole, an electrode terminal inserted into the through hole, and a sealing material that seals the through hole and is a resin member integrated with the case part and the electrode terminal. The electrode terminal also includes a shaft part inserted into the through hole and a plate part arranged along the case part. The plate part of the electrode terminal also includes a connection surface exposed to the outside of the case, a back surface opposite the connection surface, and a side surface that is continuous with the connection surface and the back surface. The sealing material also includes a base part that covers the back surface of the plate part, a side surface protection part that is continuous with the base part and covers the side surface of the plate part, and a locking part that is continuous with the upper end of the side surface protection part and covers at least a portion of the upper surface of the peripheral edge of the connection surface.

[0008] The sealing material for the energy storage device disclosed herein has a base portion integrated with a case component. The sealing material has a locking portion molded continuously with the base portion via a side protection portion. The locking portion covers the connection surface of the plate portion of the electrode terminal. In other words, the sealing material for the energy storage device disclosed herein is integrated with the case component and covers the connection surface (top surface) of the electrode terminal. This can restrict the electrode terminal from rising, thereby preventing damage to the sealing material and detachment of the electrode terminal.

[0009] Furthermore, the locking portion of the power storage device disclosed herein covers at least a portion of the periphery of the connection surface of the plate portion of the electrode terminal, thereby exposing the center of the connection surface of the electrode terminal to the outside, allowing the electrode terminal to be properly connected to an external conductive part (such as a bus bar). [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view schematically showing an electricity storage device according to a first embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view schematically showing the structure of the vicinity of an electrode terminal of the electricity storage device according to the first embodiment. [Figure 3] FIG. 3 is an enlarged plan view schematically showing the structure in the vicinity of the electrode terminals of the electricity storage device shown in FIG. [Figure 4] FIG. 4 is a perspective view schematically showing a sealing plate of the electricity storage device according to the first embodiment. [Figure 5] FIG. 5 is a perspective view schematically showing an electrode terminal of the power storage device according to the first embodiment. [Figure 6] FIG. 6 is a flowchart illustrating the manufacturing method according to the first embodiment. [Figure 7] FIG. 7 is a perspective view schematically showing an insertion step in the manufacturing method according to the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view schematically showing the accommodation step of the manufacturing method according to the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view schematically showing the injection step of the manufacturing method according to the first embodiment. [Figure 10] FIG. 10 is an enlarged cross-sectional view schematically showing the injection step of the manufacturing method according to the first embodiment. [Figure 11] FIG. 11 is an enlarged plan view schematically showing the structure in the vicinity of an electrode terminal of an electricity storage device according to another embodiment. [Figure 12] FIG. 12 is an enlarged plan view schematically showing the structure in the vicinity of an electrode terminal of an electricity storage device according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the technology disclosed herein will be described with reference to the drawings. It should be noted that matters other than those specifically mentioned in this specification that are necessary for implementing the technology disclosed herein (e.g., detailed materials for the electrode body and electrolyte) can be understood as design matters for a person skilled in the art based on the prior art in the relevant field. The technology disclosed herein can be implemented based on the content disclosed in this specification and common technical knowledge in the relevant field. Furthermore, the expression "A to B" indicating a range in this specification is intended to include the meaning of "greater than A" and "smaller than B" as well as the meaning of "greater than A" and "smaller than B."

[0012] In this specification, the term "electricity storage device" refers to a concept that encompasses devices in which charge and discharge reactions occur due to the movement of charge carriers between a pair of electrodes (positive and negative electrodes). That is, the electricity storage device in the technology disclosed herein encompasses secondary batteries such as lithium ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, as well as capacitors such as lithium ion capacitors and electric double layer capacitors.

[0013] First Embodiment A. Energy storage devices Hereinafter, one embodiment of a method for manufacturing an electricity storage device disclosed herein will be described with reference to the drawings. Fig. 1 is a perspective view that schematically shows an electricity storage device according to a first embodiment. Fig. 2 is an enlarged cross-sectional view that schematically shows a structure in the vicinity of an electrode terminal of the electricity storage device shown in Fig. 1. Fig. 3 is an enlarged plan view that schematically shows a structure in the vicinity of an electrode terminal of the electricity storage device shown in Fig. 1. Fig. 4 is a perspective view that schematically shows a sealing plate of the electricity storage device according to the first embodiment. Fig. 5 is a perspective view that schematically shows an electrode terminal of the electricity storage device according to the first embodiment.

[0014] In the drawings referred to in this specification, the symbols L, R, F, Rr, U, and D represent left, right, front, rear, top, and bottom, respectively. The symbols X, Y, and Z in the drawings represent the width, depth, and height directions of the energy storage device, respectively. However, these directions are merely defined for the convenience of explanation and do not limit the installation mode of each component in the technology disclosed herein.

[0015] As shown in FIGS. 1 and 2, the electricity storage device 100 according to this embodiment includes an electrode assembly 40 and a case 10 that houses the electrode assembly 40.

[0016] 1. Electrode body The electrode assembly 40 is a power generating element of the electricity storage device 100. As the electrode assembly 40, any electrode assembly that can be used in conventionally known electricity storage devices can be used without any particular restrictions, and therefore a detailed description thereof will be omitted. Although not shown in the drawings, an electrolyte solution is also contained inside the case 10. The composition of this electrolyte solution is also not particularly limited, and therefore a detailed description thereof will be omitted.

[0017] 2. Case The case 10 is a container that houses the electrode assembly 40. The case 10 in this embodiment includes a case main body 12 and a sealing plate 14. The case main body 12 is a box-shaped body with an upper opening. Specifically, the case main body 12 includes a bottom 12b that is an elongated rectangular plate-like member, a pair of first side walls 12c that extend upward U from long sides (sides along the width direction X) of the bottom 12b, and a pair of second side walls 12d that extend upward U from short sides (sides along the depth direction Y) of the bottom 12b. An upper opening is formed on the upper surface of the case main body 12, surrounded by the upper ends of the first side wall 12c and the second side wall 12d. Meanwhile, the sealing plate 14 is a rectangular plate-like member that closes the upper opening of the case main body 12. Specifically, the sealing plate 14 is an elongated plate-like member that extends in the width direction X. The sealing plate 14 is fitted into the upper end of the case body 12. The boundary between the case body 12 and the sealing plate 14 is joined by laser welding or the like. The case 10 (case body 12 and sealing plate 14) is preferably a metal member having a certain level of strength or higher. Examples of materials for the case 10 include metal materials such as aluminum and aluminum alloys.

[0018] Furthermore, the case 10 in this embodiment includes a case member, an electrode terminal 20, and a sealing material 30. Each component will be described below.

[0019] (1) Case parts In this specification, the term "case component" refers to a component, among the multiple components that constitute the case of an electricity storage device, to which electrode terminals and a sealant are attached. For example, in the electricity storage device 100 shown in FIG. 1, electrode terminals 20 and a sealant 30 are attached to the sealing plate 14. In this configuration, the sealing plate 14 is the case component. However, the case component is not limited to the sealing plate. For example, when electrode terminals and a sealant are attached to the case main body, the case main body is the case component.

[0020] As shown in FIG. 4, the case component (sealing plate 14) of the power storage device 100 has a through hole 14a. The through hole 14a is formed at each end of the sealing plate 14 in the width direction X. The through hole 14a in FIG. 4 is a rectangular opening in plan view. However, the planar shape of the through hole 14a is not particularly limited as long as an electrode terminal 20 (described later) can be inserted therein. Other examples of the planar shape of the through hole 14a include a circle and an ellipse. An outer surface 14b of the sealing plate 14 has an outer groove 14d surrounding the through hole 14a. Similarly, an inner surface 14c of the sealing plate 14 has an inner groove 14e surrounding the through hole 14a (see FIG. 2). As shown in FIG. 2, a portion of the sealant 30 flows into the outer groove 14d and the inner groove 14e. This improves adhesion between the sealing plate 14 and the sealant 30.

[0021] (2) Electrode terminal The electrode terminal 20 is a conductive member that is inserted into the through-hole 14a. As shown in Fig. 5, the electrode terminal 20 in this embodiment is an elongated member that extends in the height direction Z. The electrode terminal 20 has a shaft portion 22 and a plate portion 24.

[0022] The shaft portion 22 is a portion that is inserted into the through-hole 14a. As shown in FIGS. 2 and 5, the shaft portion 22 in this embodiment is a long, plate-like member that extends in the height direction Z. The shaft portion 22 is housed inside the case 10. The lower end of the shaft portion 22 is connected to the electrode body 40 (not shown). The shape of the shaft portion 22 is not limited to a plate shape, and may be a columnar shape (cylindrical, rectangular), etc.

[0023] The plate portion 24 is a portion disposed along the case component (sealing plate 14). As shown in FIG. 5, the plate portion 24 in this embodiment extends continuously from the upper end 22a of the shaft portion 22 in the width direction X. The plate portion 24 is formed by bending the tip of a long, plate-shaped conductive member. The plate portion 24 is molded to have a substantially rectangular planar shape to correspond to the substantially rectangular through-hole 14a. In this manner, the planar shape of the plate portion preferably corresponds to the planar shape of the through-hole. This facilitates resin filling in the injection step S40 described below. However, the planar shape of the plate portion is not limited to a substantially rectangular shape. For example, if the planar shape of the through-hole is circular, the planar shape of the plate portion may also be circular. Furthermore, the electrode terminal does not need to be an integrated component in which the shaft portion and the plate portion are continuous. For example, the shaft portion and the plate portion may be separately manufactured and then combined to form the electrode terminal.

[0024] The plate portion 24 has a connection surface 24a, a back surface 24b, and a side surface 24c. As shown in FIG. 2 , the connection surface 24a of the plate portion 24 is exposed to the outside of the case 10. This allows an external conductive component, such as a bus bar, to be connected to the plate portion 24 of the electrode terminal 20. The back surface 24b of the plate portion 24 is the surface opposite the connection surface 24a. This back surface 24b is covered by a base portion 32 of the sealing material 30, which will be described later. The side surface 24c is a surface that is continuous with the connection surface 24a and the back surface 24b. This side surface 24c is covered by a side surface protection portion 36 of the sealing material 30. Note that the insertion height of the electrode terminal 20 is preferably adjusted so that the back surface 24b of the plate portion 24 is positioned above the outer surface 14b of the sealing plate 14. This allows the base portion 32 and the external insulating portion 38 of the sealing material 30 to be properly formed, thereby more stably fixing each component.

[0025] (3) Sealing material The sealing material 30 is a resin member that seals the through-hole 14a of the case component (sealing plate 14). This sealing material 30 is integrated with the sealing plate 14 and the electrode terminal 20. In this specification, "integrated" refers to a state in which a metal member (sealing plate, electrode terminal, etc.) and a resin member (sealing material, etc.) are fixed together. The sealing material 30 in this embodiment includes a base portion 32, a side surface protection portion 36, and a locking portion 39. The sealing material 30 shown in FIG. 2 further includes an internal insulating portion 34 and an external insulating portion 38. Each component will be described below.

[0026] (a) Base part The base portion 32 is a resin member that covers the back surface 24b of the plate portion 24 and the case component (sealing plate 14). Specifically, the base portion 32 is a resin member that fills the through hole 14a of the sealing plate 14. The base portion 32 is integrated with the back surface 24b of the plate portion 24, the outer surface of the through hole 14a, and the upper end portion 22a of the shaft portion 22 (see FIG. 5). In this way, the base portion 32 is fixed to the electrode terminal 20 and the sealing plate 14.

[0027] (b) Internal insulation Next, the internal insulating portion 34 is a resin member that extends along the inner surface 14c of the sealing plate 14. This internal insulating portion 34 extends continuously from the base portion 32 radially outward (for example, toward the depth direction Y in FIG. 2). This internal insulating portion 34 has the function of preventing contact between the sealing plate 14 and the electrode body 40 when the electrode body 40 inside the case 10 moves up and down due to vibration or the like. Furthermore, a portion of the internal insulating portion 34 flows into the internal groove 14e of the sealing plate 14. This makes it possible to suppress movement of the sealing material 30 in the planar directions (the width direction X and the depth direction Y).

[0028] (c) External insulation The external insulating portion 38 is a resin member extending along the outer surface 14b of the sealing plate 14. Like the internal insulating portion 34, the external insulating portion 38 also extends radially outward from the base portion 32 (e.g., toward the depth direction Y in FIG. 2 ). The external insulating portion 38 functions to prevent electrical conduction between the plate portion 24 of the electrode terminal 20 and the case 10 (sealing plate 14). Specifically, if the outer surface 14b of the sealing plate 14 is exposed around the plate portion 24, electrical conduction between the electrode terminal 20 and the case 10 may occur if conductive foreign matter (such as metal powder or liquid) adheres to the plate portion 24. For this reason, it is preferable to form the external insulating portion 38 around the plate portion 24. A portion of the external insulating portion 38 flows into the external groove 14d of the sealing plate 14. This more effectively prevents the sealant 30 from moving in the planar directions (the width direction X and the depth direction Y). Furthermore, in the electricity storage device 100 according to this embodiment, the case member (sealing plate 14) is sandwiched between the internal insulating portion 34 and the external insulating portion 38. This more effectively prevents the sealant 30 from moving up and down relative to the sealing plate 14.

[0029] (d) Side protection part The side surface protective portion 36 is a resin member that is continuous with the base portion 32 and covers the side surface 24c of the plate portion 24. Specifically, the side surface protective portion 36 extends upward from the base portion 32 in a direction U along the side surface 24c of the plate portion 24. The side surface protective portion 36 is integrated with the side surface 24c of the plate portion 24. Similar to the external insulating portion 38, the side surface protective portion 36 has the function of suppressing electrical conduction between the electrode terminal 20 and the sealing plate 14 via conductive foreign matter. The side surface protective portion 36 can also restrict movement of the electrode terminal 20 in the planar directions (the width direction X and the depth direction Y). This can also contribute to suppressing damage to the sealing material 30 due to vibration of the electrode terminal 20.

[0030] (e) Locking part The locking portion 39 is continuous with the upper end of the side surface protection portion 36 and is a resin member that covers at least a portion of the peripheral edge 24a1 of the connection surface 24a. Specifically, the side surface protection portion 36 in this embodiment is erected above the peripheral edge 24a1 of the connection surface 24a of the plate portion 24 at a position U above the peripheral edge 24a1 of the connection surface 24a. The locking portion 39 extends horizontally (in the width direction X and / or the depth direction Y) from the upper end of the side surface protection portion 36 so as to cover the peripheral edge 24a1 of the connection surface 24a. The locking portion 39 is integrated with the peripheral edge 24a1 of the connection surface 24a. The locking portion 39 having this configuration can restrict the electrode terminal 20 from rising, thereby preventing damage to the sealing material 30 and detachment of the electrode terminal 20. This will be described in detail below.

[0031] First, as described above, the base portion 32 of the sealing material 30 is integrated with the sealing plate 14. Meanwhile, the locking portion 39 covers the connection surface 24a of the plate portion 24 of the electrode terminal 20. The base portion 32 and the locking portion 39 are continuously molded via the side surface protection portion 36. That is, the sealing material 30 in this embodiment is fixed to the sealing plate 14 at the base portion 32 and has the locking portion 39 that covers the connection surface 24a (upper surface) of the electrode terminal 20. As a result, the electrode terminal 20 is fixed to the sealing plate 14 via the sealing material 30, and therefore, even if the electricity storage device 100 vibrates, the electrode terminal 20 is prevented from rising. As a result, damage to the sealing material 30 and detachment of the electrode terminal 20 can be prevented.

[0032] Furthermore, the locking portion 39 in this embodiment covers at least a portion of the periphery of the connection surface 24a of the plate portion 24 of the electrode terminal 20. This prevents the insulating sealing material 30 from covering the central portion 24a2 of the connection surface 24a, and allows the central portion 24a2 of the connection surface 24a to be exposed to the outside. As a result, a sufficient connection area between the electrode terminal 20 and an external conductive component (such as a bus bar) can be secured.

[0033] As shown in Fig. 3, the locking portion 39 in this embodiment continuously covers the entire periphery of the peripheral portion 24a1 of the connection surface 24a of the plate portion 24. With this configuration, the entire periphery of the peripheral portion 24a1 of the connection surface 24a is locked by the locking portion 39, which more reliably restricts the rise of the electrode terminal 20. The width w1 of the locking portion 39 in plan view (see Fig. 3) is preferably set taking into consideration the restriction of the rise of the electrode terminal 20 and the securing of the area of ​​the central portion 24a2 of the connection surface 24a. For example, the width w1 of the locking portion 39 is set to 2 mm to 5 mm (preferably 3 mm to 4 mm).

[0034] 3, in the electrode terminal 20 of this embodiment, a recess 24e recessed from the connection surface 24a is formed between a central portion 24a2 of the connection surface 24a and the locking portion 39. As will be described in detail later, this configuration can prevent the central portion 24a2 of the connection surface 24a from being covered with resin when molding the sealant 30. This eliminates the need for a process to remove resin adhering to the central portion 24a2 of the connection surface 24a, thereby improving the manufacturing efficiency of the electricity storage device 100.

[0035] As shown in FIG. 2 , in the power storage device 100 according to this embodiment, the height position of the locking portion 39 of the sealing material 30 is equal to or lower than the height position of the central portion 24a2 of the connection surface 24a. This configuration facilitates connection between the electrode terminal 20 and the external conductive component. Specifically, when connecting the electrode terminal 20 and the external conductive component, the central portion 24a2 of the connection surface 24a of the electrode terminal 20 may be brought into surface contact with the plate-shaped external conductive component. In this case, if the locking portion 39 is positioned above the central portion 24a2 of the connection surface 24a (U), the locking portion 39 interferes, making surface contact between the electrode terminal 20 and the external conductive component difficult. In contrast, if the locking portion 39 is positioned below the central portion 24a2 of the connection surface 24a (D), the electrode terminal 20 and the external conductive component can be easily brought into surface contact. Note that in FIG. 2 , the locking portion 39 is positioned below the central portion 24a2 of the connection surface 24a (D). However, the height position of the locking portion 39 may be the same as the height position of the central portion 24a2 of the connection surface 24a. Even in this case, the electrode terminal 20 and the external conductive part can easily come into surface contact with each other.

[0036] In this embodiment, a notch 24f is formed in the peripheral edge 24a1 of the connection surface 24a. As a result, the peripheral edge 24a1 of the connection surface 24a is positioned at a lower position D than the other region (central portion 24a2) of the connection surface 24a. If the locking portion 39 is formed to cover the notch 24f, the height position of the locking portion 39 of the sealing material 30 can be set to be equal to or lower than the height position of the central portion 24a2 of the connection surface 24a.

[0037] 2. Manufacturing method of electricity storage device

[0038] Next, a method for manufacturing the electricity storage device 100 having the above configuration will be described. Fig. 6 is a flowchart illustrating the manufacturing method according to the first embodiment. As shown in Fig. 6, the manufacturing method according to this embodiment includes a preparation step S10, an insertion step S20, a storage step S30, and a pouring step S40. Each step will be described below.

[0039] (1) Preparation process S10 In this step, a case part having a through hole 14a is prepared. As described above, the case part in this embodiment is the sealing plate 14 (see FIG. 4). The detailed structure of this sealing plate 14 has already been described, so a duplicated description will be omitted.

[0040] (2) Insertion step S20 7 is a perspective view schematically illustrating the insertion step of the manufacturing method according to the first embodiment. As shown in FIG. 7, in the insertion step S20, the electrode terminal 20 is inserted into the through hole 14a. Specifically, the shaft portion 22 of the electrode terminal 20 is inserted into the through hole 14a of the sealing plate 14. At this time, the insertion position of the electrode terminal 20 in the height direction Z is adjusted so that the plate portion 24 of the electrode terminal 20 is positioned above the upper surface 14b of the sealing plate 14 at a position U above the upper surface 14b of the sealing plate 14. Furthermore, the insertion position of the electrode terminal 20 in the planar directions (the width direction X and the depth direction Y) is adjusted so that the substantially rectangular plate portion 24 covers the upper portion U of the substantially rectangular through hole 14a.

[0041] 5 and 7, the electrode terminal 20 in this embodiment includes a recess 24e. The recess 24e is a groove recessed from the connection surface 24a and is formed between a central portion 24a2 and a peripheral portion 24a1 of the connection surface 24a. The recess 24e in this embodiment is an annular recess formed along the peripheral portion 24a1 of the connection surface 24a. The recess 24e having such a configuration can prevent the resin R from entering the region inside the recess 24e (the central portion 24a2 of the connection surface 24a) in the injection step S40 described below.

[0042] Furthermore, the electrode terminal 20 in this embodiment includes a notch 24f. The notch 24f is formed by cutting the peripheral edge 24a1 of the connection surface 24a. As a result, the peripheral edge 24a1 of the connection surface 24a is positioned at a position D below the central portion 24a2. If the locking portion 39 is formed to cover this notch 24f, the locking portion 39 can be easily positioned at a position D below the central portion 24a2 of the connection surface 24a.

[0043] (3) Storage process S30 FIG. 8 is a cross-sectional view schematically illustrating the accommodation step of the manufacturing method according to the first embodiment. As shown in FIG. 8, in the accommodation step S30, the case component (sealing plate 14) and the electrode terminal 20 are placed in the internal cavity Mc of the mold M. Specifically, the internal cavity Mc of the mold M accommodates the periphery of the through hole 14a of the sealing plate 14, the entire plate portion 24, and the upper end portion 22a of the stem portion 22. On the other hand, although not shown, the lower end portion 22b (see FIG. 5) of the stem portion 22 and the central portion 14f (see FIG. 6) of the sealing plate 14 in the width direction X are not accommodated in the internal cavity Mc and are exposed to the outside of the mold M. In addition, in the accommodation step S30 of this embodiment, the electrode terminal 20 and the sealing plate 14 are reversed upside down. As a result, the back surface 24b of the plate portion 24 and the inner surface 14c of the sealing plate 14 are arranged in the upper U direction. In this case, the resin R is more likely to flow into the resin flow path Mc3 when the temperatures of the electrode terminal 20 and the mold M are low at the beginning of the injection step S40 described below. As a result, the resin R can be more effectively prevented from entering the resin blocking portion Mc0.

[0044] The mold M used in this step is made of a high-strength metal material such as stainless steel, die steel, or maraging steel. This makes it possible to prevent deformation or damage to the mold M during the injection step S40. Inside the mold M, a cavity surface Mcs is formed that corresponds to the shape of the sealing material 30 to be molded. In this specification, the "internal cavity Mc of the mold M" refers to the space surrounded by the cavity surface Mcs of the mold M. In this embodiment, the cavity surface Mcs has the following first surface M1 to fourth surface M4.

[0045] (a) First side M1 As shown in FIG. 8, in this embodiment, the cavity surface Mcs of the mold M is in surface contact with the connection surface 24a of the plate portion 24. The cavity surface Mcs in surface contact with the connection surface 24a is referred to as the "first surface M1." By bringing this first surface M1 into surface contact with the connection surface 24a, it is possible to prevent resin from adhering to the connection surface 24a. Furthermore, in this specification, the area where the connection surface 24a and the first surface M1 are in surface contact is referred to as the "resin blocking portion Mc0." However, in this embodiment, a notch portion 24f is formed in the peripheral portion 24a1 of the connection surface 24a. Therefore, a gap S is formed between the peripheral portion 24a1 of the connection surface 24a and the first surface M1. This gap S communicates with the resin flow path Mc3, which will be described later.

[0046] In this embodiment, a protrusion M1a is provided that protrudes upward U from the first surface M1. This protrusion M1a is formed at a position where it is inserted into the recess 24e of the connection surface 24a of the electrode terminal 20. This protrusion M1a is a wedge-shaped protrusion with a triangular cross-section. In the accommodation step S30, the accommodation position of the electrode terminal 20 is adjusted so that the slope of this wedge-shaped protrusion M1a and the slope of the recess 24e are in surface contact.

[0047] As shown in FIG. 8, the dimension L1 of the first surface M1 in the depth direction Y is preferably longer than the dimension LT of the plate portion 24 in the depth direction Y. This facilitates surface contact of the connection surface 24a of the plate portion 24 with the first surface M1. Specifically, if the dimension LT of the plate portion 24 and the dimension L1 of the first surface M1 are substantially equal, the plate portion 24 may ride up onto the third surface M3 of the mold M. In this case, a gap is generated in the resin blocking portion Mc0, increasing the likelihood of resin adhering to the connection surface 24a. In contrast, if the first surface M1 is wider than the plate portion 24, surface contact between the first surface M1 and the connection surface 24a is facilitated, thereby more effectively preventing resin from adhering to the connection surface 24a. For example, the difference (L1 - LT) between the dimension L1 of the first surface M1 and the dimension LT of the plate portion 24 is preferably 0.001 mm or more, more preferably 0.005 mm or more, and particularly preferably 0.01 mm or more. On the other hand, if the difference (L1-LT) between the dimension L1 of the first surface M1 and the dimension LT of the plate portion 24 becomes too large, the resin will be more likely to reach the tip Mc3a of the resin flow path Mc3 described below. From this perspective, the difference (L1-LT) between the dimension L1 of the first surface M1 and the dimension LT of the plate portion 24 is preferably 0.2 mm or less, more preferably 0.15 mm or less, and particularly preferably 0.1 mm or less.

[0048] (b) Second side M2 The second surface M2 is a cavity surface Mcs that faces the back surface 24b of the plate portion 24 with a gap therebetween. A space is formed between the second surface M2 and the back surface 24b, into which resin is filled in the injection step S40. In the following description, this space is referred to as a "first filling space Mc1." The resin filled in the first filling space Mc1 becomes the base portion 32 of the sealing material 30 (see FIG. 2).

[0049] Furthermore, the dimension L2 of the second surface M2 in the depth direction Y is longer than the dimension LT of the plate portion 24 in the depth direction Y. Both end portions of the second surface M2 in the depth direction Y extend beyond the plate portion 24 and face the inner surface 14c of the sealing plate 14. Hereinafter, the space where both end portions of the second surface M2 face the inner surface 14c of the sealing plate 14 is referred to as the "second filling space Mc2." The resin filled in this second filling space Mc2 becomes the internal insulating portion 34 of the sealing material 30 (see FIG. 2). Note that the second surface M2 of the mold M extends outward (toward the front F and the rear Rr) beyond the internal groove 14e of the sealing plate 14. As a result, the internal insulating portion 34 is formed to cover the internal groove 14e. This improves the adhesion between the sealing material 30 and the sealing plate 14. Furthermore, the resin supplied to the second filling space Mc2 enters the internal groove 14e and then reaches the contact surface Ma between the inner side surface 14c of the sealing plate 14 and the mold M. This prevents a large amount of resin from being suddenly supplied to the contact surface Ma, thereby suppressing leakage of the resin to the outside of the mold M.

[0050] (c) Third side M3 The third surface M3 is a cavity surface Mcs that faces the side surface 24c of the plate portion 24 with a gap therebetween. In the accommodation step S30, a resin flow path Mc3 is formed between the side surface 24c of the plate portion 24 and the third surface M3 of the mold M. Resin flows into this resin flow path Mc3 via the first filling space Mc1. The resin filled into this resin flow path Mc3 becomes a side surface protection portion 36 that covers the side surface 24c of the plate portion 24 (see FIG. 2). In addition, a tip Mc3a of the resin flow path Mc3 communicates with the gap S between the peripheral portion 24a1 of the connection surface 24a and the first surface M1. Note that in this embodiment, the cavity surface Mcs (i.e., the third surface M3) that forms the resin flow path Mc3 is continuous along the circumferential direction of the side surface 24c of the plate portion 24. As a result, in the manufactured power storage device 100, the side surface protection portion 36 that continuously covers the side surface 24c of the plate portion 24 is formed.

[0051] (d) 4th side M4 Next, the fourth surface M4 is a cavity surface Mcs that faces the outer surface 14b of the sealing plate 14 with a gap therebetween. The space where the fourth surface M4 of the mold M and the outer surface 14b of the sealing plate 14 face each other is referred to as the "fourth filling space Mc4." The resin filled in this fourth filling space Mc4 becomes the outer insulating portion 38 of the sealing material 30 (see FIG. 2). The fourth surface M4 of the mold M extends outward beyond the outer groove 14d of the outer surface 14b of the sealing plate 14. As a result, an inner insulating portion 34 that covers the outer groove 14d is formed. This improves the adhesion between the sealing material 30 and the sealing plate 14. Similar to the inner groove 14e, the outer groove 14d also functions to prevent resin leakage from the contact surface Mb between the outer surface 14b of the sealing plate 14 and the mold M.

[0052] (4) Injection process S40 FIG. 9 is a cross-sectional view schematically illustrating the injection step of the manufacturing method according to the first embodiment. As shown in FIG. 9, in this step, resin R is injected into the internal cavity Mc of the mold M. This allows the case component (sealing plate 14) and the sealant 30 (see FIG. 2) that seals the through-hole 14a to be integrally molded. The sealant 30 also integrates with the electrode terminal 20 (specifically, the plate portion 24 and the upper end 22a of the shaft portion 22) inserted into the through-hole 14a. Examples of the resin R filled in this step include thermoplastic resins such as polyethylene, polyamide, polypropylene, and vinyl chloride resin. The sealant 30 can be easily formed by injecting these thermoplastic resins into the internal cavity Mc and cooling them.

[0053] The injection of the resin R in this process will be described below. The mold M in this embodiment has an injection hole Ms penetrating the mold M. This injection hole Ms is formed on the second surface M2 so as to face the back surface 24b of the plate portion 24. The injection hole Ms is also connected to a resin supply source (not shown) via a transfer pipe P. The resin R supplied from the resin supply source is injected into the internal cavity Mc of the mold M via the transfer pipe P and the injection hole Ms. The injected resin R is first filled into the first filling space Mc1, which is the space with the largest volume. The resin R is then supplied via this first filling space Mc1 to the second filling space Mc2, resin flow path Mc3, fourth filling space Mc4, etc. This prevents a large amount of resin R from being suddenly supplied into a relatively narrow space, thereby suppressing resin leakage and molding defects. In particular, by supplying the resin R to the resin flow path Mc3 via the first filling space Mc1, the supply speed of the resin R toward the tip Mc3a of the resin flow path Mc3 decreases, which makes it possible to more effectively suppress the intrusion of the resin R into the resin blocking portion Mc0.

[0054] In this embodiment, a resin flow path Mc3 is formed between the side surface 24c of the plate portion 24 and the third surface M3 of the mold M. The resin flow path Mc3 communicates with a gap S between a peripheral edge portion 24a1 of the connecting surface 24a and the first surface M1 of the mold M. Therefore, the resin R supplied in the injection step S40 is filled into the gap S via the resin flow path Mc3. Specifically, as shown in FIG. 10 , the resin R that has flowed into the resin flow path Mc3 flows into the gap S via the tip Mc3a of the resin flow path Mc3. As a result, the peripheral edge portion 24a1 of the connecting surface 24a is covered with the resin R. The resin R hardens to form a locking portion 39 that covers the peripheral edge portion 24a1 of the connecting surface 24a.

[0055] As described above, in the manufacturing method according to this embodiment, the position of the electrode terminal 20 is adjusted so that the inclined surface of the wedge-shaped protrusion M1a and the inclined surface of the recess 24e are in surface contact. This prevents the resin R from penetrating inward beyond the protrusion M1a. As a result, the resin R is prevented from adhering to the central portion 24a2 of the connection surface 24a. According to this manufacturing method, a portion of the recess 24e of the electrode terminal 20 is covered by the locking portion 39, as shown in FIG. 2.

[0056] Furthermore, it is preferable that a roughened surface portion Rs be formed on the surfaces of the sealing plate 14 and the electrode terminal 20 that come into contact with the resin R. This improves adhesion to the sealant 30 after curing. For example, as shown in FIGS. 4 to 7, the roughened surface portion Rs is formed on the outer surface 14b of the sealing plate 14 around the through hole 14a, the side surface 24c of the plate portion 24, the upper end 22a of the shaft portion 22, and the like. Although not shown, the roughened surface portion Rs is also formed on the inner surface 14c of the sealing plate 14 around the through hole 14a and the back surface 24b of the plate portion 24. The roughened surface portion Rs can be formed by a conventionally known roughening treatment (sandblasting, chemical treatment, etc.). It is particularly preferable that the roughened surface portion Rs be formed on the peripheral portion 24a1 (typically the notch portion 24f) of the connection surface 24a. This further improves the connection strength between the locking portion 39 and the electrode terminal 20.

[0057] [Other embodiments] One embodiment of the technology disclosed herein has been described above. However, the technology disclosed herein is not limited to the above-described embodiment. Other embodiments of the technology disclosed herein will be described below.

[0058] As shown in Fig. 3, the locking portion 39 in the first embodiment continuously covers the entire periphery of the peripheral portion 24a1 of the connection surface 24a. However, the locking portion 39 is not limited to the shape shown in Fig. 3 as long as it covers at least a portion of the peripheral portion 24a1 of the connection surface 24a. For example, the locking portion 39 shown in Fig. 11 covers only the four corners of the connection surface 24a of the rectangular plate portion 24. Furthermore, the locking portion 39 shown in Fig. 12 covers the peripheral portion 24a1 of the connection surface 24a excluding the four corners. Both the locking portions 39 shown in Figs. 11 and 12 restrict the elevation of the electrode terminal 20 and can prevent damage to the sealing material 30 and detachment of the electrode terminal 20.

[0059] 3 and 11, a recess 24e is formed between the central portion 24a2 and the peripheral portion 24a1 of the connection surface 24a. However, the technology disclosed herein does not require a recess to be formed on the connection surface of the electrode terminal. For example, in the energy storage device 100 shown in FIG. 12, no recess is formed on the connection surface 24a of the electrode terminal 20. However, even in the configuration shown in FIG. 12, a locking portion 39 is formed on the peripheral portion 24a1 of the connection surface 24a, thereby preventing the electrode terminal 20 from rising. Note that, since no recess is formed in the configuration shown in FIG. 12, resin may adhere to the central portion 24a2 of the connection surface 24a after the sealing material 30 is formed. However, by performing a process (such as a polishing process or an etching process) to remove the resin adhered to the central portion 24a2 of the connection surface 24a, an electrode terminal 20 that can be connected to an external conductive component can be obtained. However, from the viewpoint of reducing the number of manufacturing steps and improving production efficiency, it is preferable to form a recess 24e on the connection surface 24a of the electrode terminal 20 as shown in Figures 3 and 11, thereby suppressing adhesion of resin to the central portion 24a2 of the connection surface 24a.

[0060] Also, as shown in FIG. 2, in the first embodiment, a notch 24f is formed in the peripheral portion 24a1 of the connection surface 24a, and a locking portion 39 is formed at a position D below the central portion 24a2 of the connection surface 24a. However, such a configuration does not limit the technology disclosed herein. For example, even if the locking portion is formed above the central portion of the connection surface, it can be connected to an external conductive component as long as the central portion of the connection surface is exposed to the outside. For example, if a protrusion that protrudes downward is formed on the external conductive component (such as a bus bar), it can be connected to the central portion of the connection surface even if the locking portion is located above the central portion of the connection surface.

[0061] The technology disclosed herein has been described in detail above. However, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above. In other words, the technology disclosed herein encompasses the aspects described in items 1 to 6 below.

[0062] [Item 1] An electrode body; a case for accommodating the electrode assembly; Equipped with The case is a case part having a through hole; an electrode terminal inserted into the through hole; a sealing material that is a resin member that seals the through-hole and is integrated with the case part and the electrode terminal; Including, The electrode terminal is a shaft portion inserted into the through hole; a plate portion disposed along the case part; and The plate portion is a connection surface exposed to the outside of the case; a back surface opposite to the connection surface; a side surface continuous with the connecting surface and the rear surface; Equipped with The sealing material is a base portion covering the rear surface of the plate portion and the case component; a side surface protection portion that is continuous with the base portion and covers the side surface of the plate portion; a locking portion that is continuous with the upper end of the side surface protection portion and covers at least a part of the peripheral edge of the connecting surface; The power storage device includes:

[0063] [Item 2] Item 2. The power storage device according to item 1, wherein the locking portion continuously covers the entire periphery of the connecting surface.

[0064] [Item 3] The plate portion is a plate-like portion having a rectangular planar shape, Item 2. The power storage device according to item 1, wherein the locking portion covers an upper surface of four corners of the connecting surface of the planar rectangular plate portion.

[0065] [Item 4] 4. The electricity storage device according to any one of items 1 to 3, wherein a recess recessed from the connection surface is formed between a central portion and a peripheral portion of the connection surface.

[0066] [Item 5] 5. The electricity storage device according to any one of items 1 to 4, wherein the height position of the locking portion is equal to or lower than the height position of a central portion of the connection surface.

[0067] [Item 6] providing a case part having a through hole; inserting an electrode terminal into the through hole; placing the case part and the electrode terminal in an internal cavity of a mold; a step of injecting a resin into the internal cavity of the mold to integrally mold the case part and a sealing material that seals the through hole; Including, The electrode terminal is a shaft portion to be inserted into the through hole; a plate portion that is disposed along the case part when the shaft portion is inserted into the through hole; and The plate portion is a connection surface exposed to the outside of the case part; a back surface opposite to the connection surface; a side surface continuous with the connecting surface and the back surface; Equipped with The mold is a first surface that is a cavity surface that is in surface contact with a central portion of the connection surface of the plate portion; a third surface that is a cavity surface that faces the side surface of the plate portion with a gap therebetween; It is equipped with In the placing step, a resin flow path is formed between the side surface of the plate portion and the third surface of the mold, and a gap communicating with the resin flow path is formed between at least a part of a peripheral edge of the connecting surface of the plate portion and the first surface of the mold; In the integral molding step, the resin is filled into the gap through the resin flow path. [Explanation of symbols]

[0068] 10: Case 12: Case body 14: Sealing plate 20: Electrode terminal 22: Shaft 24: Board part 30: Sealing material 32: Base part 34: Internal insulation 36: Side protection part 38: Outer insulation 39: Locking part 40: Electrode body 100: Energy storage device M: Mold Mc: internal cavity Mc0: Resin blocking part Mc1: 1st filling space Mc2: 2nd filling space Mc3: Resin flow path Mc4: 4th filling space Mcs: Cavity surface

Claims

1. An electrode body; a case for accommodating the electrode assembly; Equipped with The case is a case part having a through hole; an electrode terminal inserted into the through hole; a sealing material that is a resin member that seals the through-hole and is integrated with the case part and the electrode terminal; Including, The electrode terminal is a shaft portion inserted into the through hole; a plate portion disposed along the case part; and The plate portion is a connection surface exposed to the outside of the case; a back surface opposite to the connection surface; a side surface continuous with the connecting surface and the rear surface; Equipped with The sealing material is a base portion covering the rear surface of the plate portion and the case component; a side surface protection portion that is continuous with the base portion and covers the side surface of the plate portion; a locking portion that is continuous with the upper end of the side surface protection portion and covers at least a part of the peripheral edge of the connecting surface; The power storage device includes:

2. The power storage device according to claim 1 , wherein the locking portion continuously covers the entire periphery of the connecting surface.

3. The plate portion is a plate-like portion having a rectangular planar shape, The power storage device according to claim 1 , wherein the locking portions cover upper surfaces of four corners of the connecting surface of the planar rectangular plate portion.

4. The power storage device according to claim 1 , wherein a recess recessed from the connection surface is formed between a central portion and a peripheral portion of the connection surface.

5. The power storage device according to claim 1 , wherein the height position of the locking portion is equal to or lower than the height position of a central portion of the connection surface.

6. providing a case part having a through hole; inserting an electrode terminal into the through hole; placing the case part and the electrode terminal in an internal cavity of a mold; a step of injecting a resin into the internal cavity of the mold to integrally mold the case part and a sealing material that seals the through hole; Including, The electrode terminal is a shaft portion to be inserted into the through hole; a plate portion that is disposed along the case part when the shaft portion is inserted into the through hole; and The plate portion is a connection surface exposed to the outside of the case part; a back surface opposite to the connection surface; a side surface continuous with the connecting surface and the back surface; Equipped with The mold is a first surface that is a cavity surface that is in surface contact with a central portion of the connection surface of the plate portion; a third surface that is a cavity surface that faces the side surface of the plate portion with a gap therebetween; It is equipped with In the placing step, a resin flow path is formed between the side surface of the plate portion and the third surface of the mold, and a gap communicating with the resin flow path is formed between at least a part of a peripheral edge of the connecting surface of the plate portion and the first surface of the mold; In the integral molding step, the resin is filled into the gap through the resin flow path.

Images