Power storage element and method for manufacturing power storage element

Abstract

Provided is a power storage element comprising: a cylindrical case body in which openings are formed at both ends; a cover body that closes the openings; an electrode body housed in the case body; a spacer that is positioned between the case body and the electrode body and extends in a first direction from one opening to the other opening; and a fixing portion that fixes the electrode body and the spacer.

Description

Electric energy storage element and method for manufacturing the same 【0001】 The present invention relates to an electric energy storage element and a method for manufacturing the same. This application claims priority based on Japanese Patent Application No. 2024-215463 filed in Japan on December 10, 2024, and incorporates its content herein by reference. 【0002】 For example, Patent Document 1 discloses an electric energy storage element provided with a spacer. In the electric energy storage element disclosed in Patent Document 1, the spacer is positioned between a rectangular ceiling portion and a current collector member. Such a spacer maintains the distance between the current collector member and the ceiling portion. 【0003】 Japanese Patent No. 5849623 【0004】 The electric energy storage element may include a case body having openings formed at both ends and an electrode body housed in the case body. In such an electric energy storage element, the spacer is housed inside the case body together with the electrode body. When housing the electrode body and the spacer in the case body, directly pressing the electrode body will increase the load on the electrode body. 【0005】 The present invention has been made in view of the above problems, and an object thereof is to reduce the load when housing the electrode body in the case body in an electric energy storage element in which the electrode body is housed in the case body. 【0006】 As a means for solving the above problems, each aspect of the present invention has the following configuration. The electric energy storage element according to the first aspect of the present invention includes a cylindrical case body having openings formed at both ends, a lid body closing the openings, an electrode body housed in the case body, a spacer positioned between the case body and the electrode body and extending in a first direction which is a direction from one of the openings to the other opening, and a fixing portion fixing the electrode body and the spacer. 【0007】In a method for manufacturing an energy storage element according to a second aspect of the present invention, the energy storage element comprises a cylindrical case body having openings formed at both ends, an electrode body housed in the case body, a spacer positioned between the case body and the electrode body and extending from one opening to the other, and a fixing portion for fixing the electrode body and the spacer, wherein the spacer is pushed from one opening to insert the electrode body and the spacer into the case body. 【0008】 According to an aspect of the present invention, in an energy storage element in which an electrode body is housed in a case body, the load on the electrode body when it is housed in the case body can be reduced. 【0009】 This is a perspective view of the energy storage element according to the embodiment. This is a partially exploded perspective view of the energy storage element according to the embodiment. This is an exploded view of part III in Figure 2. This is a cross-sectional view along the line IV-IV in Figure 1. This is an enlarged view of part V in Figure 4. This is an enlarged view of part VI in Figure 4. This is a schematic diagram showing a method for manufacturing the energy storage element according to the embodiment. 【0010】 (1) A first aspect of the present invention provides a power storage element comprising: a cylindrical case body having openings formed at both ends; a lid that closes the openings; an electrode body housed in the case body; a spacer located between the case body and the electrode body and extending in a first direction from one opening to the other; and a fixing part that fixes the electrode body and the spacer. 【0011】 In the energy storage element described in (1) above of the present invention, the electrode body and the spacer are fixed by a fixing part. In other words, the electrode body and the spacer are integrated by the fixing part. Because the electrode body and the spacer are integrated by the fixing part in this way, the electrode body can be housed in the case body by pressing the spacer. Therefore, the load on the electrode body is reduced compared to when the electrode body is directly pressed into the case body. Accordingly, in an energy storage element according to one aspect of the present invention, the load on the electrode body when housing the electrode body in the case body can be reduced. 【0012】(2) In the energy storage element described in (1) above, the electrode body is formed to have a shape having a pair of short sides and a pair of long sides connecting the short sides when viewed from the first direction, and the spacer may be located between the short sides of the electrode body and the case body. 【0013】 According to the energy storage element described in (2) above, the shape of the spacer as viewed from the first direction can be reduced compared to the case where the spacer is located between the long side of the electrode body and the case body. Therefore, the energy storage element described in (2) above can reduce the spacer's occupancy within the case body and increase the electrode body's occupancy within the case body. 【0014】 (3) In the energy storage element described in (1) or (2) above, the fixing portion is a tape wrapped around the electrode body and the spacer, and the tape may be joined to the surface of the electrode body having the widest area. 【0015】 According to the energy storage element described in (3) above, for example, by joining the tape to the surface of the electrode body having the widest area, a wider contact area between the fixed part and the electrode body can be secured compared to the case where the tape is joined to a surface other than the surface having the widest area. Therefore, the energy storage element described in (3) above can achieve a higher bonding strength between the fixed part and the electrode body compared to the case where the tape is joined to a surface other than the surface having the widest area. 【0016】 (4) In the energy storage element described in any of (1) to (3) above, one end of the spacer may be in contact with the cover that closes one of the openings. 【0017】 According to the energy storage element described in (4) above, one end of the spacer is in contact with one of the lids. Therefore, the energy storage element described in (4) above can position the electrode body, which is integrated with the spacer, within the case body with reference to one end of the spacer. 【0018】(5) In a method for manufacturing an energy storage element according to a second aspect of the present invention, the energy storage element comprises a cylindrical case body having openings formed at both ends, an electrode body housed in the case body, a spacer located between the case body and the electrode body and extending from one opening to the other opening, and a fixing part for fixing the electrode body and the spacer, wherein the electrode body and the spacer are inserted into the case body by pushing the spacer from one of the openings. 【0019】 According to the method for manufacturing an energy storage element described in (5) above of the present invention, the electrode body and the spacer are fixed by a fixing part. In other words, the electrode body and the spacer are integrated by the fixing part. In this state, the electrode body is housed in the case body by pressing the spacer. Therefore, the load on the electrode body is reduced compared to the case in which the electrode body is directly pressed to house it in the case body. Accordingly, the method for manufacturing an energy storage element according to one aspect of the present invention can reduce the load on the electrode body when housing it in the case body of an energy storage element in which the electrode body is housed in the case body. 【0020】 [Embodiments] Next, embodiments of the present invention will be described based on the drawings. 【0021】 <Energy Storage Element> Figure 1 is a perspective view of the energy storage element 1. Figure 2 is a partially exploded perspective view of the energy storage element 1. Figure 3 is an exploded view of part III in Figure 2. Figure 4 is a cross-sectional view along the line IV-IV in Figure 1. Figure 5 is an enlarged view of part V in Figure 4. Figure 6 is an enlarged view of part VI in Figure 4. The energy storage element 1 is a secondary battery (single cell) that can charge and discharge electricity. More specifically, the energy storage element 1 is a non-aqueous electrolyte secondary battery such as a lithium-ion secondary battery. The energy storage element 1 is used as a battery for driving mobile vehicles such as automobiles, motorcycles, and railway vehicles for electric railways, for starting engines, etc. 【0022】 The above-mentioned vehicles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicles. In addition, the energy storage element 1 can also be used as a stationary battery for household or commercial use. 【0023】 The energy storage element 1 is not limited to a non-aqueous electrolyte secondary battery. The energy storage element 1 may be a secondary battery other than a non-aqueous electrolyte secondary battery, or it may be a capacitor. The energy storage element 1 may be a primary battery instead of a secondary battery. The energy storage element 1 may be a battery using a solid electrolyte. 【0024】 As shown in Figures 1 to 3, the energy storage element 1 mainly consists of two electrode bodies 2, a case 3 that houses each electrode body 2, positive and negative terminals 4 and a current collector 5 provided on the case 3, and leads 6 that connect the electrode bodies 2 and the current collector 5. Each electrode body 2 is formed in a flat rectangular parallelepiped shape (with an oval cross-section) and is arranged overlapping in the thickness direction. In the following description, the thickness direction (overlapping direction) of the electrode bodies 2 will be referred to as the X direction. The longitudinal direction of the electrode body 2 as viewed from the thickness direction will be referred to as the Y direction. The direction perpendicular to the X and Y directions will be referred to as the Z direction. In addition, the direction facing the center of the electrode body 2 in the Y direction may be referred to as the inside of the Y direction, and the direction opposite to the inside of the Y direction may be referred to as the outside of the Y direction. 【0025】 <Electrode Body> The electrode body 2 is an energy storage element (power generation element) that can store electricity. The electrode body 2 comprises a positive electrode plate, a negative electrode plate, and a separator (neither of which is shown in the figure) placed between the positive electrode plate and the negative electrode plate. The positive electrode plate is an electrode plate on which a positive electrode active material layer is formed on a positive electrode current collector foil. The positive electrode current collector foil is a long, strip-shaped current collector foil made of aluminum or an aluminum alloy. The negative electrode plate is an electrode plate on which a negative electrode active material layer is formed on a negative electrode current collector foil. The negative electrode current collector foil is a long, strip-shaped current collector foil made of copper or a copper alloy. 【0026】 As the current collector foil, nickel, copper, or other appropriately known materials can be used. As the positive electrode active material and negative electrode active material mentioned above, any active material capable of intercalating and deintercalating lithium ions can be used, as appropriate known materials. For the separator, for example, a microporous sheet or nonwoven fabric made of resin can be used. 【0027】Under this configuration, the electrode body 2 is formed by winding a positive electrode plate, a negative electrode plate, and a separator together with the Y direction as the central axis. In other words, the electrode body 2 is a so-called wound-type electrode body. The positive electrode plate and the negative electrode plate each have portions where the current collector foil is exposed without an active material layer being formed, as these portions are drawn out separately from both ends in the Y direction. By stacking and bundling these portions, the tabs 7 for the positive electrode and the tabs 7 for the negative electrode are formed. Thus, the tabs 7 for the positive electrode and the tabs 7 for the negative electrode in the electrode body 2 are drawn out separately from both sides in the Y direction. 【0028】 Furthermore, as shown in Figure 2, the electrode body 2 is formed in a rectangular shape having a pair of short sides 2a and a pair of long sides 2b when viewed from the Y direction (first direction). Each short side 2a extends linearly along the X direction. The two short sides 2a are arranged in the Z direction and are parallel to each other. Each long side 2b extends linearly along the Z direction. The two long sides 2b are arranged in the X direction and are parallel to each other. Each long side 2b connects one short side 2a to the other short side 2a. In other words, each long side 2b connects the short sides 2a to each other. 【0029】 <Case> Case 3 comprises a cylindrical case body 8 having openings 8a at both ends in the Y direction, and two lids 9 that close the two openings 8a. The case body 8 and lids 9 are formed from a weldable metal such as stainless steel, aluminum, or aluminum alloy. However, they are not limited to this, and the case body 8 and lids 9 can also be formed from resin. 【0030】 The case body 8 is formed in a flat rectangular parallelepiped shape with a thin thickness in the X direction to correspond to the shape of the electrode body 2. The electrode body 2 is housed in the case body 8, covered with an insulating sheet 10. As for the electrolyte, there are no particular restrictions on the type as long as it does not impair the performance of the energy storage element 1, and various types can be selected. 【0031】The two lids 9 have the same basic structure. Therefore, in the following description, only one of the two lids 9 will be described, and only the differences between the two will be described. The lid 9 is a rectangular plate-like member that is long in the Z direction when viewed from the Y direction, corresponding to the shape of the opening 8a of the case body 8. The lid 9 is connected to the periphery of the opening 8a of the case body 8 by welding or the like. This seals the inside of the case body 8. 【0032】 One of the two lids 9 is provided with a gas discharge valve 11 near the first end 9a in the Z direction. The gas discharge valve 11 releases pressure when the pressure inside the case body 8 rises. An electrolyte injection port 12 is provided near the second end 9b, opposite to the first end 9a of the lid 9. The electrolyte injection port 12 is used to inject electrolyte into the case body 8. A lid through-hole 13 is formed closer to the first end 9a than the electrolyte injection port 12 of the lid 9. A terminal 4 is inserted into the lid through-hole 13 via an insulator 14. 【0033】 <Insulator> The insulator 14 is formed of a resin material having electrical insulating properties. Examples of this resin material include polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), and polyether sulfone (PES). The insulator 14 located on the positive electrode tab 7 side and the insulator 14 located on the negative electrode tab 7 side have the same configuration and are arranged symmetrically with respect to the electrode body 2. For this reason, in the following description, only one of the two insulators 14 will be described, and the description of the other will be omitted. 【0034】 As shown in Figure 3, the insulator 14 is arranged on both sides of the lid 9 in the Z direction. That is, the insulator 14 comprises an outer insulator 15 arranged on the outer surface 9c of the lid 9 and an inner insulator 16 arranged on the inner surface 9d of the lid 9. 【0035】The outer insulator 15 has an outer base portion 17 positioned on the outer surface 9c of the lid 9. The outer base portion 17 is formed in a square shape when viewed from the Y direction. A side wall 18 is formed on the outer circumference of the outer base portion 17, rising outward in the Y direction. The side wall 18 and the outer base portion 17 form a terminal storage recess 19. A cylindrical portion 21 is formed in the center of the outer base portion 17 when viewed from the Y direction, projecting inward in the Y direction. The cylindrical portion 21 penetrates the outer base portion 17 in the Y direction. The cylindrical portion 21 is fitted into the lid through hole 13 of the lid 9. The tip of the cylindrical portion 21 and the inner surface 9d of the lid 9 are located on the same plane. 【0036】 The inner insulator 16 is formed in the shape of a rectangular plate that is elongated in the Z direction when viewed from the Y direction. More specifically, the inner insulator 16, which is located on the side of the lid 9 where the gas discharge valve 11 is provided, extends from the lid through hole 13 of the lid 9 to the gas discharge valve 11. The inner insulator 16 has an inner through hole 23 formed coaxially with the lid through hole 13. The inner diameter of the inner through hole 23 is the same as the inner diameter of the cylindrical portion 21 of the outer insulator 15. 【0037】 <Current Collectors> The current collectors 5 are arranged so as to overlap each other on the inner surface 16a of each inner insulator 16 in the Y direction. The two current collectors 5 are the positive electrode current collector 5 located on the positive electrode tab 7 side and the negative electrode current collector 5 located on the negative electrode tab 7 side. These current collectors 5 have the same configuration and are arranged symmetrically with respect to the electrode body 2. For this reason, in the following explanation, only one of the two current collectors 5 will be described, and the explanation of the other will be omitted. 【0038】 The material of the current collector 5 is not particularly limited. However, for example, the positive electrode current collector 5 of the positive electrode current collector 5 is made of aluminum or an aluminum alloy, similar to the positive electrode current collector foil of the electrode body 2. The negative electrode current collector 5 is made of copper or a copper alloy, similar to the negative electrode current collector foil of the electrode body 2. 【0039】 The current collector 5 is formed in the shape of a rectangular plate that is elongated in the Z direction when viewed from the Y direction. More specifically, the current collector 5 is formed to overlap most of the inner insulator 16. The thickness of the current collector 5 is, for example, about 1 to 3 mm. 【0040】 The current collector 5 has a current collector through-hole 26 that penetrates the current collector 5. The inner diameter of the current collector through-hole 26 is the same as the inner diameter of the inner through-hole 23. The current collector 5 has protrusions 27 formed on both ends in the Z direction and on one side in the X direction. The protrusions 27 are formed in a C shape when viewed from the Y direction. These protrusions 27 are formed by pressing the current collector 5, which pushes the outer surface 5b side toward the inner surface 5a side and bends it. That is, recesses are formed on the outer surface 5b of the current collector 5 to correspond to the protrusions 27. 【0041】 <Terminals> The terminals 4 are inserted through the lid through holes 13 of each lid 9 via an insulator 14. The terminals 4 provide electrical conductivity between the inside and outside of the lid 9 (case 3). The two terminals 4 are a positive terminal 4 located on the positive tab 7 side and a negative terminal 4 located on the negative tab 7 side. The positive terminal 4 is made of, for example, aluminum or an aluminum alloy. In contrast, the negative terminal 4 is made of, for example, copper or a copper alloy. These terminals 4 have the same configuration and are arranged symmetrically with respect to the electrode body 2. For this reason, in the following description, only one of the two terminals 4 will be described, and the description of the other will be omitted. 【0042】 The terminal 4 comprises a shaft portion 35 and a head portion 36 integrally provided at the axial end of the shaft portion 35. The shaft portion 35 is inserted into the lid through-hole 13 of each lid 9 via an insulator 14. The diameter of the shaft portion 35 is the same as or slightly smaller than the inner diameter of the cylindrical portion 21 of the outer insulator 15. The head portion 36 is formed in a square shape when viewed from the Y direction. The size of the outer shape of the head portion 36 is such that it can be housed in the terminal housing recess 19 of the outer insulator 15. 【0043】 In this configuration, the terminal 4 is inserted into the cylindrical portion 21 of the outer insulator 15, the inner through-hole 23 of the inner insulator 16, and the current collector through-hole 26 of the current collector 5, with the tip of the shaft portion 35 opposite to the head portion 36 facing the cover 9 from the outside in the Y direction. The head portion 36 is then housed in the terminal housing recess 19 of the outer insulator 15. As a result, the tip of the shaft portion 35 protrudes from the inner surface 5a of the current collector 5 through the current collector through-hole 26. 【0044】At the tip of the protruding shaft portion 35, a caulking portion 37 is formed by performing spin caulking. As a result, the lid body 9, the insulator 14, the current collector 5, and the terminal 4 are integrated. The current collector 5 and the terminal 4 are connected via the lid body 9 and the insulator 14. The caulking portion 37 is housed in the recess 25 of the current collector 5. 【0045】 <Lead> There are a positive electrode lead 6 that electrically connects the positive electrode tab 7 and the positive electrode terminal 4, and a negative electrode lead 6 that electrically connects the negative electrode tab 7 and the negative electrode terminal 4. These leads 6 have the same configuration. Each lead 6 is formed in a rectangular plate shape that is long in the Z direction when viewed from the Y direction. More specifically, the length of the lead 6 in the Y direction is the same as the length of the inner insulator 16 in the Y direction. The thickness of the lead 6 is, for example, about 0.5 to 2 mm. 【0046】 The material of the lead 6 is not particularly limited. However, for example, the positive electrode lead 6 among the positive electrode and negative electrode leads 6 is formed of aluminum or an aluminum alloy, etc., similar to the positive electrode current collector foil of the electrode body 2. The negative electrode lead 6 is formed of copper or a copper alloy, etc., similar to the negative electrode current collector foil of the electrode body 2. 【0047】 <Insulating Sheet> The insulating sheet 10 (fixed portion) insulates the case body 8 and the electrode body 2. The insulating sheet 10 is formed of a tape made of a resin sheet such as PP or PE, for example. The insulating sheet 10 is wound around the electrode body 2 and the two spacers 50, and fixes the electrode body 2 and the two spacers 50. The spacers 50 are located between the case body 8 and the electrode body 2. In the present embodiment, each spacer 50 is located between the case body 8 and the short side 2a of the electrode body 2 and the case body 8 when viewed from the Y direction. The insulating sheet 10 is, for example, an adhesive tape with an adhesive attached to one side, and is joined to both the electrode body 2 and the spacer 50. The electrode body 2 and the spacer 50 are fixed to each other and integrated by being adhered to the insulating sheet 10 respectively. 【0048】The insulating sheet 10 is fixed so that the spacer 50 is positioned between the short side 2a of the electrode body 2 and the case body 8, and is joined to the surface of the electrode body 2 that is orthogonal to the X direction. The surface of the electrode body 2 that is orthogonal to the X direction has a larger area than the surface orthogonal to the Z direction and the surface orthogonal to the Y direction, and is the surface having the largest area of the electrode body 2. The surface of the electrode body 2 that is orthogonal to the X direction is referred to as the maximum surface 2c of the electrode body 2. That is, in the present embodiment, the insulating sheet 10 is joined to the maximum surface 2c of the electrode body 2. The insulating sheet 10 may be formed of a single tape. Further, the insulating sheet 10 may be formed of a plurality of tapes. 【0049】 The length dimension of the insulating sheet 10 in the Y direction is larger than the length dimension of the electrode body 2 in the Y direction. That is, the length in the first direction of the fixing portion is longer than the length in the first direction of the electrode body. For example, when the length dimension of the electrode body 2 in the Y direction is 200 mm, the length dimension of the insulating sheet 10 in the Y direction is larger than 200 mm. 【0050】 <Spacer> The spacer 50 is positioned between the case body 8 and the electrode body 2 and fixes the position of the electrode body 2 within the case body 8. The spacer 50 has insulating properties and is formed of, for example, resin. The spacer 50 restricts the movement of the electrode body 2 with respect to the case body 8. The spacer 50 is arranged so as to contact each of the surfaces of the electrode body 2 that are orthogonal to the Z direction. The two spacers 50 are the spacer 50 that contacts one of the two surfaces of the electrode body 2 that are orthogonal to the Z direction and the spacer 50 that contacts the other of the two surfaces of the electrode body 2 that are orthogonal to the Z direction. These spacers 50 have the same configuration and are arranged symmetrically with the electrode body 2 interposed therebetween. Therefore, in the following description, only one of the two spacers 50 will be described, and the description of the other will be omitted. 【0051】The spacer 50 is formed in a straight line so as to extend along the Y direction. The Y direction is the first direction, which is the direction from one opening 8a of the case body 8 to the other opening 8a. In other words, the spacer 50 is formed so as to extend in the first direction, which is the direction from one opening 8a of the case body 8 to the other opening 8a. The length dimension of the spacer 50 in the Y direction is greater than the length dimension of the electrode body 2 in the Y direction. For example, if the length dimension of the electrode body 2 in the Y direction is 200 mm, then the length dimension of the spacer 50 in the Y direction is greater than 200 mm. Furthermore, the length dimension of the spacer 50 in the Y direction may be greater than the length dimension of the insulating sheet 10 in the Y direction. In other words, the length of the spacer in the first direction may be longer than the length of the fixing part in the first direction. This allows the spacer 50 to be pressed while the spacer 50 and the lid 9 are in direct contact, so that the electrode body 2 can be reliably inserted into the case body 8. 【0052】 As shown in Figure 5, one of the two end faces 51 of the spacer 50 in the Y direction is away from the lid 9. The other end face 51 of the spacer 50 in the Y direction is in contact with the lid 9, as shown in Figure 6. Of the two end faces 51, the one away from the lid 9 is called the first end face 52, and the one in contact with the lid 9 is called the second end face 53. The first end face 52 is away from the inner surface 9d of one of the lids 9 in the Y direction. The second end face 53 is in contact with the inner surface 9d of the other lid 9 from the inside. 【0053】 The first end face 52 is separated from the inner surface 9d of the lid 9, which allows it to absorb dimensional tolerances of the spacer 50 and the case 3, and to accommodate the spacer 50 in the case 3. In addition, the second end face 53 is in contact with the inner surface 9d of the lid 9, which determines the position of the electrode body 2, which is integrated with the spacer 50, relative to the lid 9. 【0054】<Manufacturing Method for Energy Storage Element> Next, the manufacturing method for the energy storage element 1 will be described. First, after forming the electrode body 2, leads 6 corresponding to each tab 7 are connected in advance. As for the connection method at this time, welding such as ultrasonic connection, laser welding or resistance welding, or mechanical connection such as crimping can be used. Subsequently, the periphery of the electrode body 2 is covered with an insulating sheet 10. The electrode body 2 is wrapped with the insulating sheet 10 together with the spacer 50. The spacer 50 is fixed to the electrode body 2 in contact with the surface of the electrode body 2 perpendicular to the Z direction. As for the method of connecting the tab 7 and the leads 6, ultrasonic connection is preferred. 【0055】 Meanwhile, the insulators 14, current collectors 5, and terminals 4 are pre-assembled onto the two lids 9. Next, the current collector 5 assembled on one of the lids 9 is superimposed on the lead 6 on the second end face 53 side of the spacer 50. Then, the superimposed current collector 5 and lead 6 are connected. One method of connection is laser welding. 【0056】 Next, as shown in Figure 7, the lid 9, to which the current collector 5 connected to the lead 6 is assembled, is placed against the second end face 53 of the spacer 50, and the lid 9 is pressed with a jig or the like (not shown) to house the electrode body 2 inside the case body 8. Furthermore, the lid 9 that pressed the electrode body 2 is used to close one of the openings 8a of the case body 8. The lid 9 that pressed the electrode body 2 is kept in contact with the second end face 53 of each spacer 50. 【0057】 Next, the current collector 5 assembled to the other lid 9 and the lead 6 on the first end face 52 side of the spacer 50 are superimposed. Then, the superimposed current collector 5 and lead 6 are connected. One possible method of connection is laser welding. Furthermore, this lid 9 is used to close the other opening 8a of the case body 8. As shown in Figure 5, a gap S is formed between the first end face 52 of each spacer 50 and the lid 9. After this, welding is performed around the case body 8 and the two lids 9 to seal the case 3. 【0058】Each tab 7 is bent so as to be slightly folded. Inside the case 3 are the internal insulator 16, current collector 5, lead 6, tab 7, and electrode body 2. The terminal 4 penetrates the inside and outside of the lid 9. Next, electrolyte (non-aqueous electrolyte) is poured into the case body 8 through the liquid injection port 12 of the lid 9. This completes the manufacturing of the energy storage element 1. 【0059】 <Function and Effects> As described above, the energy storage element 1 of this embodiment comprises a case body 8, a lid 9, an electrode body 2, and an insulating sheet 10. The case body 8 is formed in a cylindrical shape with openings 8a formed at both ends. The lid 9 closes the openings 8a. The electrode body 2 is housed in the case body 8. The spacer 50 is located between the case body 8 and the electrode body 2. The spacer 50 is also formed to extend in the Y direction, which is the direction from one opening 8a to the other opening 8a. The insulating sheet 10 fixes the spacer 50 and the electrode body 2 to the spacer 50. 【0060】 In this embodiment of the energy storage element 1, the electrode body 2 and the spacer 50 are fixed together by an insulating sheet 10. In other words, the electrode body 2 and the spacer 50 are integrated by the insulating sheet 10. Because the electrode body 2 and the spacer 50 are integrated by the insulating sheet 10 in this way, the electrode body 2 can be housed in the case body 8 by pressing the spacer 50. Therefore, the load on the electrode body 2 is reduced compared to the case in which the electrode body 2 is directly pressed into the case body 8. Accordingly, in this embodiment of the energy storage element 1 in which the electrode body 2 is housed in the case body 8, the load on the electrode body 2 when housing it in the case body 8 can be reduced. 【0061】 Furthermore, in the energy storage element 1 of this embodiment, the electrode body 2 is formed to have a shape that, when viewed from the Y direction, has a pair of short sides 2a and a pair of long sides 2b connecting the short sides 2a. The spacer 50 is located between the short sides 2a of the electrode body 2 and the case body 8. 【0062】In this embodiment of the energy storage element 1, the shape of the spacer 50 as viewed from the Y direction can be reduced compared to the case where the spacer 50 is located between the long side 2b of the electrode body 2 and the case body 8. Therefore, in this embodiment of the energy storage element 1, the occupancy rate of the spacer 50 within the case body 8 can be reduced, and the occupancy rate of the electrode body 2 within the case body 8 can be increased. 【0063】 Furthermore, in the energy storage element 1 of this embodiment, the insulating sheet 10 is a tape wrapped around the electrode body 2 and the spacer 50. The insulating sheet 10 is bonded to the largest surface 2c of the electrode body 2, which has the widest surface area. 【0064】 In this embodiment of the energy storage element 1, by joining the insulating sheet 10 to the maximum surface 2c of the electrode body 2, a wider contact area between the insulating sheet 10 and the electrode body 2 can be secured compared to the case where the insulating sheet 10 is joined to a surface other than the maximum surface 2c of the electrode body 2. Therefore, in this embodiment of the energy storage element 1, the bonding strength between the insulating sheet 10 and the electrode body 2 can be increased compared to the case where the insulating sheet 10 is joined to a surface other than the maximum surface 2c. 【0065】 Furthermore, in the energy storage element 1 of this embodiment, the second end face 53, which is one end of the spacer 50, is in contact with the lid 9. In this embodiment of the energy storage element 1, one end of the spacer 50 is in contact with one of the lids 9. Therefore, in this embodiment of the energy storage element 1, the position of the electrode body 2, which is integrated with the spacer 50, within the case body 8 can be positioned with reference to the second end face 53 of the spacer 50. 【0066】In the manufacturing method of the energy storage element 1 of this embodiment, the electrode body 2 and the spacer 50 are inserted into the case body 8 by pushing the spacer 50 from one side of the opening 8a. In this manufacturing method of the energy storage element 1 of this embodiment, the electrode body 2 and the spacer 50 are fixed by the insulating sheet 10. In other words, the electrode body 2 and the spacer 50 are integrated by the insulating sheet 10. In this state, the electrode body 2 is housed in the case body 8 by pushing the spacer 50. Therefore, the load on the electrode body 2 is reduced compared to when the electrode body 2 is directly pushed into the case body 8. Accordingly, the manufacturing method of the energy storage element 1 of this embodiment can reduce the load when housing the electrode body 2 in the case body 8 in the energy storage element 1 in which the electrode body 2 is housed in the case body 8. 【0067】 [Modifications] The present invention is not limited to the embodiments described above, and includes various modifications to the embodiments described above, without departing from the spirit of the present invention. 【0068】 For example, the above-described embodiment described a configuration in which two spacers 50 are provided. However, the present invention is not limited thereto. The number of spacers 50 may be changed. 【0069】 In the above-described embodiment, the electrode body 2 and the spacer 50 were integrated using an insulating sheet 10. However, the present invention is not limited thereto. As a fixing part for fixing the electrode body 2 and the spacer 50, for example, a resin part formed by curing an adhesive may be used. Alternatively, a fixing part formed from an insulating material other than resin may be used. 【0070】 In the above-described embodiment, a configuration was described in which the second end face 53 of the spacer 50 is in contact with the lid 9. However, the present invention is not limited thereto. The second end face 53 of the spacer 50 is not required to be in contact with the lid 9. 【0071】 This invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries. 【0072】1...Energy storage element 2...Electrode body 2a...Short side 2b...Long side 2c...Maximum surface 3...Case 8...Case body 8a...Opening 9...Lid 10...Insulating sheet (fixing part) 50...Spacer 51...End face 52...First end face 53...Second end face S...Gap

Claims

1. A power storage element comprising: a cylindrical case body having openings formed at both ends; a lid that closes the openings; an electrode body housed in the case body; a spacer positioned between the case body and the electrode body and extending in a first direction from one opening to the other; and a fixing part that fixes the electrode body and the spacer.

2. The electrode body is formed in a shape having a pair of short sides and a pair of long sides connecting the short sides when viewed from the first direction, and the spacer is located between the short sides of the electrode body and the case body, as described in claim 1.

3. The energy storage element according to claim 1 or 2, wherein the fixing portion is a tape wrapped around the electrode body and the spacer, and the tape is joined to the surface of the electrode body having the widest area.

4. The energy storage element according to claim 1 or 2, wherein one end of the spacer is in contact with one of the lids that closes one of the openings.

5. A method for manufacturing an energy storage element, comprising: a cylindrical case body with openings formed at both ends; an electrode body housed in the case body; a spacer positioned between the case body and the electrode body and extending from one opening to the other; and a fixing part for fixing the electrode body and the spacer, wherein the electrode body and the spacer are inserted into the case body by pushing the spacer from one opening.

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