Method for manufacturing power storage device, and power storage device

Abstract

The invention relates to a method for manufacturing an electrical storage device and an electrical storage device. Comprises: a step for preparing a case member having a through-hole; a step for inserting an electrode terminal into the through-hole; a step for arranging the case member and the electrode terminal (20) in an inner cavity of a mold (M); and a step for injecting a resin (R) into the inner cavity of the mold. The electrode terminal has a shaft portion (22) and a plate portion (24). In addition, the plate part is provided with a connecting surface (24a), a back surface (24b) and a side surface (24c). A cavity surface (Mcs) of the mold includes a first surface (M1) in surface contact with the connection surface of the plate portion, a second surface (M2) facing a side surface of the plate portion with a gap therebetween, and a protruding portion (M1a) protruding from the first surface to a peripheral edge portion (24a1) of the connection surface. During the injection of the resin, the injection amount into the internal cavity (Mc) is controlled so that the resin flowing into the resin flow path (Mc3) is blocked by the convex part. Therefore, the resin is prevented from adhering to the connecting surface.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing an electric storage device and the electric storage device. Background Art

[0002] Energy storage devices such as secondary batteries are used as power sources for various electrical products. These devices include an electrode assembly and a housing that houses the electrode assembly. The housing, for example, includes a box-shaped housing body with an opening and a sealing plate that closes the opening. The housing also includes electrode terminals for connection to external conductive components (such as busbars) and a sealant that insulates the electrode terminals from the housing.

[0003] An example of a housing for an electrical storage device is disclosed in Japanese patent application publication No. 2022-103899. The cover (sealing plate) described in the document includes a terminal component (electrode terminal), a sealing plate having a mounting hole for mounting the terminal component, and a resin seal. Moreover, the terminal component is mounted on the mounting hole of the sealing plate in a state engaged with the seal. The seal is formed by injection molding. Specifically, first, a mold having an internal cavity of a shape corresponding to the seal is prepared. Next, a sealing plate and a terminal component are arranged in the internal cavity of the mold. Then, the internal cavity of the mold is filled with resin. Thus, a seal integrated with the sealing plate and the terminal component can be easily formed.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2022-103899

[0005] In addition, in order to connect to external conductive components such as busbars, the electrode terminal needs to have a connection surface that is exposed to the outside when installed in the housing. The external conductive component is connected to the central portion of the connection surface. However, if the component tolerances of the various components (mold, sealing plate, electrode terminal, etc.) become larger during the injection molding of the seal, the resin may sometimes adhere to the central portion of the connection surface of the electrode terminal. In this case, a process for removing the resin is required, which reduces the manufacturing efficiency of the storage device. Summary of the Invention

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

[0007] The method for manufacturing an electrical storage device disclosed herein includes: preparing a housing component having a through-hole; inserting an electrode terminal into the through-hole; arranging the housing component and the electrode terminal in the internal cavity of a mold; and injecting resin into the internal cavity of the mold to integrally mold the housing component and a sealant that seals the through-hole. In this manufacturing method, the electrode terminal includes: a shaft portion that is inserted into the through-hole; and a plate portion that is configured to extend along the housing component after the shaft portion is inserted into the through-hole. The plate portion includes a connection surface exposed to the exterior of the housing component, a back surface opposite the connection surface, and a side surface continuous with the connection surface and the back surface. The mold includes a first surface serving as a cavity surface that is in surface contact with at least the peripheral edge of the connection surface of the plate portion; a third surface serving as a cavity surface that is spaced apart from the side surface of the plate portion; and a protrusion that protrudes from the first surface toward the peripheral edge of the connection surface. Furthermore, in the manufacturing method disclosed herein, during the integral molding process, the amount of resin injected into the internal cavity is controlled so that the resin that reaches between the peripheral portion of the connecting surface and the first surface via the resin flow path between the side surface and the third surface is blocked by the protrusion.

[0008] Generally speaking, a space (resin flow path) is formed between the side surface of the plate portion of the electrode terminal and the cavity surface (second surface) of the mold. The resin supplied to the resin flow path serves as a side protection portion that prevents conduction between the plate portion of the electrode terminal and the housing. However, the side surface of the plate portion of the electrode terminal is continuous with the connection surface. Therefore, if a gap is generated between the cavity surface (first surface) of the mold and the connection surface of the electrode terminal, there is a risk that the resin will invade the gap between the first surface and the connection surface through the resin flow path. In contrast, the cavity surface of the mold used in the manufacturing method disclosed herein is provided with a convex portion protruding from the first surface toward the peripheral portion of the connection surface. The convex portion can block the resin that reaches the peripheral portion of the connection surface through the resin flow path. As a result, the resin can be prevented from adhering to the central portion of the connection surface. As a result, the frequency of removing the resin adhering to the central portion of the connection surface is reduced, which can contribute to improving the manufacturing efficiency of the storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a flowchart illustrating the manufacturing method according to the first embodiment.

[0010] Figure 2 It is a perspective view schematically showing a sealing plate used in the production method according to the first embodiment.

[0011] Figure 3 It is a perspective view schematically showing an electrode terminal used in the manufacturing method according to the first embodiment.

[0012] Figure 4It is a perspective view schematically showing the inserting step of the manufacturing method according to the first embodiment.

[0013] Figure 5 It is a cross-sectional view schematically showing the housing step of the manufacturing method according to the first embodiment.

[0014] Figure 6 It is a cross-sectional view schematically showing the injection step of the manufacturing method according to the first embodiment.

[0015] Figure 7 It is an enlarged cross-sectional view schematically showing the injection step of the manufacturing method according to the first embodiment.

[0016] Figure 8 It is a perspective view schematically showing the electric storage device according to the first embodiment.

[0017] Figure 9 It is an enlarged cross-sectional view schematically showing the structure near the electrode terminals of the electrical storage device according to the first embodiment.

[0018] Figure 10 An enlarged cross-sectional view schematically showing an injection step in the production method according to the second embodiment.

[0019] Figure 11 It is a cross-sectional view schematically showing an injection step of a production method that does not employ the technology disclosed herein.

[0020] Description of Reference Numerals

[0021] 10…housing; 12…housing body; 14…sealing plate; 20…electrode terminal; 22…shaft portion; 24…plate portion; 24a…connecting surface; 24e…recessed portion; 30…seal; 32…base portion; 34…internal insulating portion; 36…side protecting portion; 38…external insulating portion; 40…electrode body; 100…electrical storage device; M…mold; M1…first surface; M1a…convex portion; M2…second surface; M3…third surface. DETAILED DESCRIPTION

[0022] Hereinafter, the embodiments of the technology disclosed herein will be described with reference to the accompanying drawings. In addition, matters other than those specifically mentioned in this specification and required for the implementation of the technology disclosed this time (for example, detailed materials of the electrode body and electrolyte, etc.) should be understood as design matters of those skilled in the art in this field based on the prior art. The technology disclosed here can be implemented based on the contents disclosed in this specification and the technical common sense in this field. In addition, the expression "A to B" indicating the range in this specification includes the meaning of "greater than A" and "less than B" in addition to the meaning of "greater than A and less than B".

[0023] In this specification, the term "electrical storage device" encompasses devices that generate charge and discharge reactions by transferring charge carriers between a pair of electrodes (a positive electrode and a negative electrode). Specifically, the electrical storage devices described in the technology disclosed herein include not only secondary batteries such as lithium-ion batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, but also capacitors such as lithium-ion capacitors and electric double-layer capacitors.

[0024] <First embodiment>

[0025] 1. Method for manufacturing an electric storage device

[0026] An embodiment of the method for manufacturing an electrical storage device disclosed herein will be described below with reference to the accompanying drawings. In the drawings referenced in this specification, the reference symbols L, R, F, Rr, U, and D represent left, right, front, rear, top, and bottom, respectively. Furthermore, the reference symbols X, Y, and Z represent the width, depth, and height of the electrical storage device, respectively. However, these directions are merely defined for ease of explanation and do not limit the arrangement of the components in the disclosed technology.

[0027] Figure 1 1 is a flowchart illustrating the manufacturing method involved in the first embodiment. Figure 1 As shown, the manufacturing method according to this embodiment includes a preparation step S10, an insertion step S20, a housing step S30, and an injection step S40. Each step will be described below.

[0028] (1) Preparation step S10

[0029] In this step, a housing component having a through hole is prepared. In this specification, the "housing component" refers to a component on which electrode terminals and seals are mounted among the multiple components constituting the housing of the electrical storage device. For example, in the Figure 8 The illustrated electrical storage device 100 uses a housing 10 comprising a housing body 12 and a sealing plate 14. Furthermore, in this electrical storage device 100, electrode terminals 20 and a sealing member 30 are attached to the sealing plate 14. In this configuration, the sealing plate 14 serves as a housing component. However, the housing component is not limited to the sealing plate. For example, when electrode terminals and a sealing member are attached to the housing body, the housing body serves as a housing component.

[0030] Figure 2 : is a perspective view schematically showing a sealing plate used in the manufacturing method according to the first embodiment. Figure 2 As shown, the housing member (sealing plate 14 ) in this embodiment is a long plate-shaped member extending in the width direction X. Furthermore, through holes 14 a are provided at both ends of the sealing plate 14 in the width direction X, respectively. Figure 2The through hole 14a is a rectangular opening in a top view. The planar shape of the through hole 14a is not particularly limited as long as the electrode terminal 20 described later can be inserted. As another example of the planar shape of the through hole 14a, a circular shape, an elliptical shape, etc. can be cited. In addition, an external groove 14d surrounding the through hole 14a is formed on the outer side surface 14b of the sealing plate 14. Similarly, an internal groove 14e surrounding the through hole 14a is also formed on the inner side surface 14c of the sealing plate 14 (see Figure 5 The outer groove 14d and the inner groove 14e can contribute to improving the adhesion between the sealing plate 14 and the sealing member 30 after injection molding, and the details will be described later.

[0031] (2) Insertion step S20

[0032] Figure 3 : is a perspective view schematically showing an electrode terminal used in the manufacturing method according to the first embodiment. Figure 4 1 is a perspective view schematically showing the insertion process of the manufacturing method according to the first embodiment. Figure 4 As shown, in the inserting step S20, the electrode terminal 20 is inserted into the through hole 14a. Figure 3 As shown, the electrode terminal 20 in this embodiment is a long member extending in the height direction Z. The electrode terminal 20 includes a shaft portion 22 and a plate portion 24 .

[0033] The shaft portion 22 is a portion inserted into the through hole 14a. The shaft portion 22 is housed inside the housing 10 in the manufactured electrical storage device 100. Figure 3 and Figure 9 As shown, the shaft portion 22 in this embodiment is a long plate-shaped member extending in the height direction Z. In the manufactured storage device 100, the lower end portion 22b of the shaft portion 22 is connected to the electrode body 40 (see Figure 9 ), the details will be described later. In addition, the shape of the shaft portion 22 is not limited to a plate shape, and may also be a columnar shape (cylindrical shape, prism shape) or the like.

[0034] The plate portion 24 is a member arranged so as to be along the outer shell member (sealing plate 14) when the shaft portion 22 is inserted into the through hole 14a. Figure 3 As shown, the plate portion 24 in this embodiment extends continuously from the upper end of the shaft portion 22 in the width direction X. The plate portion 24 is formed by bending the front end of a long plate-shaped conductive component. In addition, the planar shape of the plate portion 24 is approximately rectangular. Figure 4As shown, the insertion position of the electrode terminal 20 in a top view is adjusted in such a way that the roughly rectangular plate portion 24 covers the upper U of the roughly rectangular through-hole 14a. In this way, it is preferred that the planar shape of the plate portion is a shape corresponding to the planar shape of the through-hole. For example, when the planar shape of the through-hole is circular, the planar shape of the plate portion can also be circular. Thereby, the filling of the resin in the injection step S40 described later becomes easy. In addition, the electrode terminal may not be an integral component in which the shaft portion and the plate portion are continuous. For example, the shaft portion and the plate portion may be made separately, and the electrode terminal may be constructed by combining the two.

[0035] The plate portion 24 in this embodiment includes a connecting surface 24a exposed to the outside of the housing member (sealing plate 14), a back surface 24b opposite to the connecting surface 24a, and a side surface 24c continuous with the connecting surface 24a and the back surface 24b. Figure 9 As shown, when the storage device 100 is constructed, the connection surface 24a of the plate portion 24 is arranged outside the housing 10. Thus, external conductive components such as bus bars can be connected to the plate portion 24 of the electrode terminal 20. In addition, the back surface 24b and the side surface 24c of the plate portion 24 are covered by the seal 30. In addition, the insertion height of the electrode terminal 20 is preferably adjusted in such a manner that the back surface 24b of the plate portion 24 is arranged at a position U above the outer side surface 14b of the sealing plate 14. Thus, the flow path between the first filling space Mc1 and the fourth filling space Mc4 described later can be sufficiently ensured. As a result, the properly formed Figure 9 The base portion 32 of the seal 30 and the external insulating portion 38 can more stably fix the components.

[0036] In addition, the electrode terminal 20 in this embodiment has a recessed portion 24e formed on the peripheral portion 24a1 of the connection surface 24a. The recessed portion 24e is an annular groove formed continuously along the peripheral portion 24a1 of the connection surface 24a. The recessed portion 24e is formed to receive the convex portion M1a of the mold M (see Figure 7 ) are integrated, and the details will be described later.

[0037] (3) Accommodation step S30

[0038] Figure 5 1 is a cross-sectional view schematically showing the accommodating step of the manufacturing method according to the first embodiment. Figure 5 As shown, in the housing step S30, the housing member (sealing plate 14) and the electrode terminal 20 are arranged 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 shaft portion 22. On the other hand, although not shown in the figure, the lower end portion 22b of the shaft portion 22 (see Figure 3), the central portion 14f in the width direction X of the sealing plate 14 (see Figure 1 ) is not housed in the internal cavity Mc but is exposed outside the mold M. Furthermore, in the housing step S30 of this embodiment, the vertical positions of the electrode terminal 20 and the sealing plate 14 are reversed. This positions the back surface 24b of the plate portion 24 and the inner surface 14c of the sealing plate 14 at the upper side U. In this case, at the initial stage of the injection step S40, described later, when the temperatures of the electrode terminal 20 and the mold M are relatively low, the resin R easily flows into the resin flow path Mc3. As a result, the resin R can be more effectively prevented from entering the resin shielding portion Mc0.

[0039] In addition, the mold M used in this process is made of a high-strength metal material such as stainless steel, mold steel, or maraging steel. This can suppress deformation and damage to the mold M in the injection step S40. In addition, a cavity surface Mcs corresponding to the shape of the seal 30 to be molded is formed inside the mold M. The "internal cavity Mc of the mold M" in this specification refers to the space surrounded by the cavity surface Mcs of the mold M. Moreover, the cavity surface Mcs in this embodiment has the following first surface M1 to fourth surface M4.

[0040] (a) Surface 1 M1

[0041] like Figure 5 As shown, the first surface M1 is a cavity surface Mcs that is in surface contact with at least the peripheral portion 24a1 of the connecting surface 24a of the plate portion 24. In this way, if the peripheral portion 24a1 of the connecting surface 24a is in surface contact with the first surface M1, the resin can be prevented from invading the central portion 24a2 of the connecting surface 24a. In addition, the first surface M1 in this embodiment is a flat surface that is in surface contact with the entire connecting surface 24a of the plate portion 24. In other words, the first surface M1 in this embodiment is not only in surface contact with the peripheral portion 24a1 of the connecting surface 24a, but also in surface contact with the central portion 24a2 of the connecting surface 24a. Thus, it is possible to more appropriately prevent the resin from adhering to the central portion 24a2 of the connecting surface 24a. In this specification, the area where the central portion 24a2 of the connecting surface 24a is in surface contact with the first surface M1 is referred to as the "resin shielding portion Mc0".

[0042] The mold M in this embodiment includes a protrusion M1a that protrudes from the first surface M1 toward the peripheral edge 24a1 of the connecting surface 24a of the plate portion 24. This protrusion M1a has the function of blocking resin flowing from the peripheral edge 24a1 of the connecting surface 24a toward the central portion 24a2, as will be described in detail later. This prevents the resin from adhering to the central portion 24a2 of the connecting surface 24a. Furthermore, the protrusion M1a in this embodiment is an annular protrusion that is continuously provided circumferentially, extending across the entire circumference of the peripheral edge 24a1 of the connecting surface 24a of the plate portion 24, facing the peripheral edge 24a1.

[0043] In addition, if Figure 5 As shown, it is preferred that the dimension L1 of the first surface M1 in the depth direction Y is longer than the dimension LT of the plate portion 24 in the depth direction Y. Thus, it is easy to make the connecting surface 24a of the plate portion 24 come into surface contact with the first surface M1. Specifically, when the dimension LT of the plate portion 24 is approximately the same as the dimension L1 of the first surface M1, there is a risk that the plate portion 24 will hang over the third surface M3 of the mold M. In this case, a gap is generated in the resin shielding portion Mc0, so the possibility of the resin adhering to the connecting surface 24a becomes higher. In contrast, if the first surface M1 is made wider than the plate portion 24, the surface contact between the first surface M1 and the connecting surface 24a becomes easier, so it is possible to more appropriately prevent the resin from adhering to the connecting 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 is too large, the resin is likely to reach the front end Mc3a of the resin flow path Mc3 described later. From this point of view, 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.

[0044] (b) Surface 2 M2

[0045] The second surface M2 is a cavity surface Mcs that is spaced apart from the back surface 24b of the plate portion 24. A space is formed between the second surface M2 and the back surface 24b to be filled with resin in the injection step S40. In the following description, this space is referred to as the "first filling space Mc1." The resin filled into the first filling space Mc1 becomes the base portion 32 of the seal 30 (see Figure 9 ).

[0046] In addition, 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. Furthermore, both ends of the second surface M2 in the depth direction Y extend beyond the plate portion 24 and face the inner side surface 14c of the sealing plate 14. Hereinafter, the space where both ends of the second surface M2 face the inner side 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 seal 30 (see FIG. 1 ). Figure 9). In addition, the second surface M2 of the mold M extends to a position farther outward (front F and rear Rr) than the internal groove 14e of the sealing plate 14. As a result, the internal insulating portion 34 is formed in a manner covering the internal groove 14e. Thus, the adhesion between the seal 30 and the sealing plate 14 can be improved. In addition, after entering the internal groove 14e, the resin supplied to the second filling space Mc2 reaches the contact surface Ma between the inner side surface 14c of the sealing plate 14 and the mold M. Thus, it is possible to prevent a large amount of resin from being rapidly supplied to the contact surface Ma, thereby suppressing the leakage of resin to the outside of the mold M.

[0047] (c) Surface 3 M3

[0048] The third surface M3 is a cavity surface Mcs that is spaced apart from the side surface 24c of the plate portion 24. A resin flow path Mc3 for resin to flow into is formed between the third surface M3 and the side surface 24c. The resin filled in the resin flow path Mc3 becomes a side protection portion 36 (see FIG. 3 ) that covers the side surface 24c of the plate portion 24. Figure 9 ). The side protection portion 36 becomes an insulating component to prevent the plate portion 24 from being electrically connected to the housing 10 (sealing plate 14), and the details will be described later. Figure 5 As shown, the front end Mc3a of the resin flow path Mc3 is adjacent to the resin shielding portion Mc0.

[0049] Furthermore, in the present embodiment, the cavity surface Mcs (i.e., the third surface M3) forming 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 storage battery device 100, the side protection portion 36 is continuously formed on the side surface 24c of the plate portion 24. Thus, the conduction between the plate portion 24 and the housing 10 (sealing plate 14) can be more appropriately suppressed. In addition, according to the technology disclosed herein, it is possible to suppress the resin R from invading the resin shielding portion Mc0 through the front end Mc3a of the resin flow path Mc3. Therefore, when a resin flow path Mc3 that is continuous along the circumferential direction is formed, it is also possible to suppress the adhesion of the resin to the connecting surface 24a of the plate portion 24.

[0050] (d) M4 on the 4th side

[0051] Next, the fourth surface M4 is the cavity surface Mcs that faces the outer side surface 14b of the sealing plate 14 with a gap therebetween. The space where the fourth surface M4 of the mold M faces the outer side surface 14b of the sealing plate 14 is referred to as the "fourth filling space Mc4." The resin filled in the fourth filling space Mc4 becomes the outer insulating portion 38 of the seal 30 (see Figure 9). In addition, the fourth surface M4 of the mold M extends to a position outside the outer groove 14d of the outer side surface 14b of the sealing plate 14. As a result, an internal insulating portion 34 covering the outer groove 14d is formed. This can improve the adhesion between the seal 30 and the sealing plate 14. In addition, similar to the above-mentioned internal groove 14e, the external groove 14d also has the function of suppressing resin leakage from the contact surface Mb between the outer side surface 14b of the sealing plate 14 and the mold M.

[0052] (4) Injection Step S40

[0053] Figure 6 1 is a cross-sectional view schematically showing the injection step of the manufacturing method according to the first embodiment. Figure 6 As shown, in this step, resin R is injected into the internal cavity Mc of the mold M. This allows the outer shell member (sealing plate 14) and the seal 30 (see FIG. 1 ) that seals the through hole 14a to be aligned. Figure 9 ) is integrally molded. Furthermore, the seal 30 is also integrated with the electrode terminal 20 (specifically, the plate portion 24 and the upper end portion 22a of the shaft portion 22) inserted into the through-hole 14a. The resin R filled in this step can be a thermoplastic resin such as polyethylene, polyamide, polypropylene, or polyvinyl chloride. By injecting these thermoplastic resins into the internal cavity Mc and cooling them, the seal 30 can be easily formed.

[0054] The injection of resin R in this process will be described below. The mold M in this embodiment has an injection hole Ms that passes through the mold M. The injection hole Ms is formed on the second surface M2 in a manner opposite to the back surface 24b of the plate portion 24. In addition, the injection hole Ms is connected to a resin supply source (not shown) via a delivery pipe P. The resin R supplied from the resin supply source is injected into the internal cavity Mc of the mold M via the delivery pipe P and the injection hole Ms. Moreover, the injected resin R is first filled into the space with the largest volume, that is, the first filling space Mc1. Then, the resin R is supplied to the second filling space Mc2, the resin flow path Mc3, the fourth filling space Mc4, etc. via the first filling space Mc1. In this way, it is possible to prevent a large amount of resin R from being rapidly supplied to a relatively narrow space, thereby suppressing resin leakage and poor molding. 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 front end Mc3a of the resin flow path Mc3 is reduced. This can more preferably suppress the intrusion of the resin R into the resin shielding portion Mc0.

[0055] As described above, the mold M in this embodiment includes a protrusion M1a that projects from the first surface M1 toward the peripheral edge 24a1 of the connecting surface 24a of the plate portion 24. Furthermore, in this process, the amount of resin R injected into the internal cavity Mc is controlled so that the resin R that flows through the resin flow path Mc3 between the side surface 24c and the third surface M3 and reaches the area between the peripheral edge 24a1 of the connecting surface 24a and the first surface M1 is blocked by the protrusion M1a. This prevents the resin R from adhering to the central portion 24a2 of the connecting surface 24a. This point will be explained while comparing it with a configuration that does not employ the technology disclosed herein. Figure 7 : is an enlarged cross-sectional view schematically showing the injection step of the manufacturing method according to the first embodiment. Figure 11 It is a cross-sectional view schematically showing an injection step of a production method that does not employ the technology disclosed herein.

[0056] Figure 11 The mold N shown includes a first surface N1 that is in surface contact with the connecting surface 124a of the plate portion 124, and a third surface N3 that is spaced apart from the side surface 124c of the plate portion 124. In this case, a resin flow path Nc3 is formed between the side surface 124c and the third surface N3. The front end Nc3a of this resin flow path Nc3 is adjacent to the portion where the connecting surface 124a and the first surface N1 are in surface contact. Therefore, if a gap S is generated between the connecting surface 124a and the first surface N1 due to component tolerances, etc., the resin R easily intrudes into the gap S through the front end Nc3a of the resin flow path Nc3. As a result, the resin adheres to the central portion 124a2 of the connecting surface 124a of the plate portion 124, necessitating a process for removing the resin.

[0057] On the other hand, Figure 7 As shown, in this embodiment, a protrusion M1a protrudes from the first surface M1 of the mold M toward the peripheral edge 24a1 of the connecting surface 24a of the plate portion 24. This protrusion M1a is located between the front end Mc3a of the resin flow path Mc3 and the central portion 24a2 of the connecting surface 24a. Therefore, the protrusion M1a can block the resin R that reaches the peripheral edge 24a1 of the connecting surface 24a via the front end Mc3a of the resin flow path Mc3. Therefore, according to the manufacturing method of this embodiment, even if the connecting surface 24a and the first surface M1 are not in full contact due to component tolerances, resulting in a gap in the resin shielding portion Mc0, the resin R can be prevented from adhering to the central portion 24a2 of the connecting surface 24a. This reduces the frequency of resin removal after the injection step S40, thereby contributing to improved manufacturing efficiency of the electrical storage device 100.

[0058] In addition, even if the convex portion M1a is provided on the first surface M1, if the low-viscosity resin R is excessively injected into the internal cavity Mc, the resin R may also pass over the convex portion M1a and leach into the central portion 24a2 of the connecting surface 24a. Therefore, in the injection process S40 in this embodiment, the injection amount of the resin R into the internal cavity Mc is controlled so that the resin R reaching the peripheral portion 24a1 of the connecting surface 24a is blocked by the convex portion M1a. In this way, it is possible to appropriately suppress the resin R from adhering to the central portion 24a2 of the connecting surface 24a. In addition, the timing of stopping the injection of the resin R varies according to the viscosity of the resin R, the injection speed of the resin R, the size of the resin flow path Mc3, the protrusion amount of the convex portion M1a, etc., and is therefore not limited to a specific injection time. For example, after determining the size of each component and the type of resin, a preliminary test can be carried out to investigate the relationship between the amount of resin R adhering to the central portion 24a2 of the connecting surface 24a and the injection conditions (injection speed, injection time). An appropriate timing for stopping the injection of the resin R can be determined based on the results of this preliminary test.

[0059] As described above, the protrusion M1a in this embodiment is an annular protrusion that is continuously provided in the circumferential direction, extending across the entire circumference of the peripheral edge 24a1 of the connecting surface 24a of the plate portion 24 and facing the connecting surface 24a. This annular protrusion M1a can prevent the resin R from invading the resin shielding portion Mc0 from the front end Mc3a of the resin flow path Mc3 throughout the entire circumference. As a result, the resin R can be more reliably prevented from adhering to the central portion 24a2 of the connecting surface 24a. Furthermore, forming an annular protrusion is not essential in the technology disclosed herein. Specifically, the position of the resin R invading the circumferential surface 24a of the plate portion 24 is affected by various factors (such as the shape of the mold, the shape of the electrode terminal, the position of the injection hole, the viscosity of the resin, and the injection speed of the resin). Therefore, if the position where the resin R is likely to invade is determined in advance, a local protrusion can be formed in that portion that is likely to invade. For example, there is a tendency for the amount of resin R to invading to increase in the portion of the peripheral edge of the connecting surface close to the injection hole. Therefore, in the technology disclosed herein, it is also possible to provide protrusions only in locations where resin intrusion is relatively high. This structure can also prevent resin from adhering to the central portion of the connection surface. Furthermore, in areas where resin R intrudes but does not reach the connection surface, protrusions may not be provided.

[0060] Furthermore, in this embodiment, a recessed portion 24e is formed on the peripheral edge 24a1 of the connection surface 24a of the electrode terminal 20, into which the protrusion M1a of the mold M engages. This structure reliably prevents damage to the electrode terminal 20 and deformation of the mold M. Specifically, in the technology disclosed herein, the protrusion of the mold intrudes into the peripheral edge of the connection surface of the electrode terminal. This allows the protrusion to block resin directed toward the center of the connection surface. However, if the peripheral edge of the connection surface, which the protrusion intrudes into, is flat, the protrusion of the mold must be used to press and deform the peripheral edge of the connection surface. This poses a risk of damaging the electrode terminal or deforming the mold. In contrast, if the recessed portion 24e is pre-formed on the peripheral edge 24a1 of the connection surface 24a of the electrode terminal 20, there is no need for the protrusion M1a of the mold M to press and deform the connection surface 24a, thereby preventing damage to the electrode terminal 20 and deformation of the mold M.

[0061] In addition, the convex portion M1a in this embodiment is a conical convex portion whose cross-sectional area decreases as it moves toward the front end. According to the conical convex portion M1a, the intrusion of the resin R into the central portion 24a2 of the connection surface 24a can be more appropriately suppressed. Specifically, the front end of the conical convex portion M1a is sharp, so that the connection surface 24a of the electrode terminal 20 and the recess 24e can be easily fitted. Thus, the intrusion of the resin R caused by poor fitting can be prevented. In addition, in the method of squeezing and deforming the peripheral portion of the connection surface by the convex portion of the mold, stress is concentrated on the front end of the conical convex portion, so the squeezing and deformation of the connection surface of the electrode terminal becomes easy.

[0062] Furthermore, as the taper angle θ of the protrusion M1a increases, the strength of the protrusion M1a tends to increase. On the other hand, as the taper angle θ of the protrusion M1a decreases, the protrusion M1a becomes more likely to intrude into the peripheral edge 24a1 of the connecting surface 24a of the electrode terminal 20. Considering this conflicting relationship, the taper angle θ of the tip of the protrusion M1a is preferably within the range of 30° to 90°.

[0063] Furthermore, when a recess 24e is pre-formed in the peripheral portion 24a1 of the connection surface 24a of the electrode terminal 20 as in this embodiment, the side surface 24e1 of the recess 24e is preferably inclined so as to come into surface contact with the inclined surface M1b of the tapered protrusion M1a. Specifically, the inclination angle of the side surface 24e1 of the recess 24e is preferably within a range of ±1° of the inclination angle of the inclined surface M1b of the protrusion M1a. With this configuration, even if the protrusion M1a is slightly misaligned with respect to the insertion position of the recess 24e, the side surface 24e1 of the recess 24e can still come into surface contact with the inclined surface M1b of the protrusion M1a. Thus, even if the accommodation position deviates during the accommodation step S30, the intrusion of resin into the central portion 24a2 of the connection surface 24a can be suppressed.

[0064] In addition, it is preferable to form a roughened surface portion Rs on the surface in contact with the resin R of the sealing plate 14 and the electrode terminal 20. This can improve the adhesion with the cured seal 30. For example, Figures 2 to 4 As shown, the roughened surface portion Rs is formed on the outer side surface 14b of the sealing plate 14, the side surface 24c of the plate portion 24, the upper end portion 22a of the shaft portion 22, etc. around the through hole 14a. In addition, although not shown in the figure, the roughened surface portion is also formed on the inner side surface 14c of the sealing plate 14, the back surface 24b of the plate portion 24, etc. around the through hole 14a. In addition, the roughened surface portion Rs can be formed by a conventionally known roughening treatment (sandblasting, chemical treatment, etc.). Among the above-mentioned parts, if the roughened surface portion Rs is formed on the side surface 24c of the plate portion 24, the circulation speed of the resin R in the resin flow path Mc3 is reduced. As a result, it is more difficult for the resin R to reach the front end Mc3a of the resin flow path Mc3. Therefore, from the viewpoint of suppressing the adhesion of the resin R to the connecting surface 24a of the plate portion 24, it is particularly preferred that the roughened surface portion Rs is formed on the side surface 24c of the plate portion 24.

[0065] 2.Electrical storage equipment

[0066] Next, the electric storage device manufactured by the above-mentioned manufacturing method will be described. Figure 8 It is a perspective view schematically showing the electric storage device according to the first embodiment. Figure 9 It is schematically represented Figure 8 An enlarged cross-sectional view of the structure near the electrode terminals of the electrical storage device shown.

[0067] like Figure 8 and Figure 9 As shown, the electrical storage device 100 according to this embodiment includes an electrode body 40 and a housing 10 that houses the electrode body 40. Although not shown, an electrolyte is also contained within the housing 10. The electrode body 40 and the electrolyte constitute the power generation elements of the electrical storage device 100. These power generation elements can be used without particular limitation in conventional electrical storage devices, and therefore a detailed description thereof will be omitted.

[0068] The housing 10 is a flat box-shaped container having an internal space. The housing 10 in this embodiment includes a housing body 12 and a sealing plate 14. The housing body 12 is a box-shaped body having an upper surface opening 12a. Specifically, the housing body 12 includes a bottom 12b which is a long rectangular plate-shaped member, a pair of first side walls 12c extending upward U from the long sides (sides along the width direction X) of the bottom 12b, and a pair of second side walls 12d extending upward U from the short sides (sides along the depth direction Y) of the bottom 12b. Moreover, on the upper surface of the housing body 12, an upper surface opening 12a is formed which is surrounded by the respective upper ends of the first side wall 12c and the second side wall 12d. On the other hand, the sealing plate 14 is a rectangular plate-shaped member that blocks the upper surface opening 12a of the housing body 12. Specifically, as Figure 2 As shown, the sealing plate 14 is embedded in the upper end of the housing body 12. Furthermore, the boundary between the housing body 12 and the sealing plate 14 is joined by laser welding or the like. Furthermore, the housing 10 (housing body 12 and sealing plate 14) is preferably a metal component having a certain strength or greater. Examples of materials for the housing 10 include metal materials such as aluminum and aluminum alloys.

[0069] As described above, in the electrical storage device 100 according to this embodiment, the housing component to which the electrode terminals 20 and the seal 30 are mounted is the sealing plate 14. Specifically, the housing 10 according to this embodiment includes a housing component (sealing plate 14) having a through-hole 14a, the electrode terminal 20 inserted into the through-hole 14a, and the seal 30, a resin component that seals the through-hole 14a and is integrated with the housing component (sealing plate 14). The term "integrated" in this specification refers to the fixed bonding of metal components (sealing plate, electrode terminals, etc.) and resin components (sealing, etc.).

[0070] Furthermore, the electrode terminal 20 has a shaft portion 22 inserted into the through hole 14a of the sealing plate 14, and a plate portion 24 arranged along the outer shell member (sealing plate 14). Furthermore, the plate portion 24 has a connection surface 24a exposed to the outside of the outer shell 10, a back surface 24b on the side opposite to the connection surface 24a, and a side surface 24c continuous with the connection surface 24a and the back surface 24b. In the electrical storage device 100 having the electrode terminal 20 of this structure, the shaft portion 22 is connected to the electrode body 40 inside the outer shell 10. On the other hand, an external conductive component such as a bus bar (not shown) is connected to the connection surface 24a of the plate portion 24. As a result, a conductive path from the electrode body 40 to the external conductive component can be easily formed.

[0071] Furthermore, in the electrical storage device 100 according to this embodiment, a recessed portion 24e is formed on the peripheral edge 24a1 of the connection surface 24a, recessed from the connection surface 24a. This recessed portion 24e can be preformed before the receiving step S30, or can be produced by compressing and deforming the connection surface 24a using the protrusion M1a of the mold M. Furthermore, the electrode terminal 20 having this recessed portion 24e has the advantage of clearly defining the boundary between the resin and the metal on the top surface of the electrode terminal 20, thereby enabling more accurate determination of the terminal position during image inspection of the electrical storage device 100 after manufacture.

[0072] On the other hand, the seal 30 includes a side protection portion 36 that covers the side surface 24c of the plate portion 24. According to the side protection portion 36, the conduction between the plate portion 24 and the housing 10 (sealing plate 14) can be suppressed. Specifically, if the side surface 24c of the plate portion 24 is exposed, there is a risk that the electrode terminal 20 and the housing 10 will be conductive when conductive foreign matter (metal powder, liquid, etc.) adheres to the side surface 24c. The side protection portion 36 can prevent the conduction between the plate portion 24 and the housing 10 through such conductive foreign matter. The side protection portion 36 is formed by filling the resin flow path Mc3 with resin R (refer to Figure 6 and Figure 7 ).

[0073] In addition, the seal 30 in this embodiment includes a base portion 32, an internal insulating portion 34, and an external insulating portion 38 in addition to the side protection portion 36. The base portion 32 is a portion that fills the through hole 14a of the sealing plate 14. The base portion 32 is in contact with the back surface 24b of the plate portion 24, the outer side surface of the through hole 14a, and the upper end portion 22a of the shaft portion 22 (see Figure 4 ) is a resin component that is in contact with the sealing plate 14. The base portion 32 becomes a base material for fixing the electrode terminal 20 and the sealing plate 14 in an insulating state. In addition, the internal insulating portion 34 is a resin component that extends along the inner side surface 14c of the sealing plate 14. The internal insulating portion 34 insulates the shaft portion 22 from the sealing plate 14. In addition, the internal insulating portion 34 also has the function of preventing the sealing plate 14 from contacting the electrode body 40 when the electrode body 40 moves up and down due to vibration, etc. In addition, the external insulating portion 38 is a resin component that extends along the outer side surface 14b of the sealing plate 14. By providing this external insulating portion 38, not only the side surface 24c of the plate portion 24 can be covered with an insulating component, but also the outer side surface 14b of the sealing plate 14 can be covered with an insulating component. As a result, conduction between the electrode terminal 20 and the sealing plate 14 via conductive foreign matter can be more appropriately prevented.

[0074] The above describes one embodiment of the technology disclosed herein. However, the technology disclosed herein is not limited to the above embodiment. Other embodiments of the technology disclosed herein will be described below.

[0075] <Second embodiment>

[0076] For example, the mold M in the first embodiment includes a tapered convex portion M1a (see Figure 7 ). However, the cross-sectional shape of the convex portion is not particularly limited, and various shapes such as a rectangle and a semicircle can be adopted. For example, Figure 10 : is an enlarged cross-sectional view schematically showing the injection process of the manufacturing method involved in the second embodiment. Figure 10 As for the mold M shown in FIG. 1 , a convex portion M1a having a semicircular cross section is formed on the first surface M1. Figure 7 Compared with the conical convex portion M1a shown in FIG. 2 , the strength is excellent, so the deformation and damage of the mold can be suppressed. However, when the insertion position relative to the concave portion 24e deviates, the convex portion M1a with a semicircular cross section is difficult to block the intrusion of the resin R. Therefore, from the perspective of reliably preventing the resin R from adhering to the central portion 24a2 of the connecting surface 24a, it is preferable to form Figure 7 The conical protrusion M1a is shown.

[0077] <Other implementation methods>

[0078] In addition, if Figure 7 and Figure 10 As shown, the mold M in the first and second embodiments has a first surface M1 that is in surface contact with the entire surface of the connecting surface 24a. However, the first surface of the mold may be in contact only with the peripheral portion of the connecting surface. As described above, according to the technology disclosed herein, the resin toward the central portion of the connecting surface can be blocked by the convex portion, so even if the central portion of the connecting surface is not in surface contact with the first surface, the adhesion of the resin to the central portion of the connecting surface can be suppressed. Among them, from the viewpoint of more reliably suppressing the adhesion of the resin to the central portion of the connecting surface, it is preferred to make the entire surface of the connecting surface in surface contact with the first surface of the mold as in the first and second embodiments.

[0079] The above describes the technology disclosed herein in detail. However, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples described above. Specifically, the technology disclosed herein includes the embodiments described in Items 1 through 7 below.

[0080] [Project 1]

[0081] A method for manufacturing an electrical storage device, wherein the method comprises: preparing a shell component having a through hole; inserting an electrode terminal into the through hole; arranging the shell component and the electrode terminal in an internal cavity of a mold; and injecting resin into the internal cavity of the mold and integrally molding the shell component and a sealant that seals the through hole, wherein the electrode terminal comprises: a shaft portion that is inserted into the through hole; and a plate portion that is configured to extend along the shell component when the shaft portion is inserted into the through hole, wherein the plate portion comprises: a connecting surface that is formed on the shell component. exposed to the outside; a back surface on the side opposite to the above-mentioned connecting surface; and a side surface continuous with the above-mentioned connecting surface and the above-mentioned back surface, the above-mentioned mold comprises: a first surface, which is a cavity surface in contact with at least the peripheral portion of the above-mentioned connecting surface of the above-mentioned plate portion; a third surface, which is a cavity surface opposite to the above-mentioned side surface of the above-mentioned plate portion with a gap; and a convex portion protruding from the above-mentioned first surface toward the peripheral portion of the above-mentioned connecting surface, in the above-mentioned one-piece molding process, the amount of resin injected into the above-mentioned internal cavity is controlled so that the resin reaching the peripheral portion of the above-mentioned connecting surface and the above-mentioned first surface through the resin flow path between the above-mentioned side surface and the above-mentioned third surface is blocked by the above-mentioned convex portion.

[0082] [Project 2]

[0083] The method for manufacturing an electric storage device according to item 1, wherein the protrusion is an annular protrusion continuously provided in the circumferential direction over the entire circumference of the peripheral edge portion of the connecting surface so as to face the connecting surface.

[0084] [Item 3]

[0085] The method for manufacturing an electric storage device according to item 1 or 2, wherein a recessed portion into which the raised portion of the mold fits is formed on a peripheral edge portion of the connecting surface.

[0086] [Item 4]

[0087] The method for manufacturing an electric storage device according to any one of items 1 to 3, wherein the convex portion is a tapered convex portion whose cross-sectional area decreases toward the front end.

[0088] [Item 5]

[0089] The method for manufacturing an electrical storage device according to any one of items 1 to 4, wherein a recess into which the projection of the mold fits is formed on the periphery of the connecting surface, and a side surface of the recess is inclined so as to come into surface contact with an inclined surface of the tapered projection.

[0090] [Item 6]

[0091] The method for manufacturing an electric storage device according to any one of items 1 to 5, wherein the first surface of the mold is a flat surface that is in surface contact with the entire surface of the connecting surface of the plate portion.

[0092] [Item 7]

[0093] A storage device, wherein the storage device comprises: an electrode body; and a shell for accommodating the electrode body, the shell comprising: a shell component having a through hole; an electrode terminal inserted into the through hole; and a sealant for sealing the through hole, which is a resin component integrated with the shell component, the electrode terminal comprising: a shaft portion inserted into the through hole; and a plate portion arranged along the shell component, the plate portion comprising: a connecting surface exposed to the outside of the shell; a back surface on the side opposite to the connecting surface; and a side surface continuous with the connecting surface and the back surface, the sealant comprising a side protection portion covering the side surface of the plate portion, and a recessed portion recessed from the connecting surface is formed on the peripheral edge of the connecting surface.

Claims

1. A method for manufacturing an electric storage device, wherein: The method for manufacturing the electric storage device comprises: a step of preparing a housing component having a through hole; inserting an electrode terminal into the through hole; a step of placing the housing member and the electrode terminal in an internal cavity of a mold; and a step of injecting resin into the internal cavity of the mold to integrally mold the housing component and a sealant that seals the through-hole; The electrode terminal has: a shaft portion inserted into the through hole; and The plate portion is configured to extend along the housing member when the shaft portion is inserted into the through hole. The plate portion comprises: a connecting surface exposed on the outside of the housing component; a back surface on the side opposite to the connecting surface; and side surface, continuous with the connecting surface and the back surface, The mold has: The first surface is a cavity surface that is in surface contact with at least a peripheral portion of the connecting surface of the plate portion; a third surface, which is a cavity surface facing the side surface of the plate portion with a gap therebetween; and a convex portion protruding from the first surface toward the peripheral edge of the connecting surface, In the integral molding step, the amount of resin injected into the internal cavity is controlled so that the resin that reaches between the peripheral portion of the connecting surface and the first surface via the resin flow path between the side surface and the third surface is blocked by the protrusion.

2. The method for manufacturing an electric storage device according to claim 1, wherein: The protrusion is an annular protrusion provided continuously in the circumferential direction over the entire circumference of the peripheral edge portion of the connection surface so as to face the connection surface.

3. The method for manufacturing an electric storage device according to claim 1, wherein: A recessed portion into which the convex portion of the mold fits is formed at a peripheral edge portion of the connecting surface.

4. The method for manufacturing an electrical storage device according to claim 1, wherein: The convex portion is a tapered convex portion whose cross-sectional area decreases toward the front end.

5. The method for manufacturing an electric storage device according to claim 1, wherein: A recessed portion into which the convex portion of the die fits is formed at a peripheral edge portion of the connecting surface, and a side surface of the recessed portion is inclined so as to come into surface contact with an inclined surface of the tapered convex portion.

6. The method for manufacturing an electric storage device according to claim 1, wherein: The first surface of the mold is a flat surface that is in surface contact with the entire connection surface of the plate portion.

7. An electric storage device, wherein: The power storage device comprises: Electrode body; and a housing accommodating the electrode body, The housing comprises: a housing component having a through hole; an electrode terminal inserted into the through hole; and The sealing member seals the through hole and is a resin member integrated with the housing member. The electrode terminal has: a shaft portion inserted into the through hole; and a plate portion, arranged along the housing member, The plate portion comprises: a connecting surface exposed on the outside of the housing; a back surface on the side opposite to the connecting surface; and side surface, continuous with the connecting surface and the back surface, The seal member includes a side protection portion covering the side surface of the plate portion, A recessed portion recessed from the connecting surface is formed at a peripheral edge portion of the connecting surface.

Images