Electrochemical element assembling method and assembling device

Abstract

Provided are an electrochemical element assembling method and assembling device that make it possible to obtain sufficient battery performance. A method for assembling an electrochemical element 1 comprises: a step S1 for preparing a recessed container 10; a step S2 for disposing a shape retention conductor 40 to the inner surface of a bottom portion 11 of the recessed container 10; a step S3 for disposing an electrode body 20 to the top surface of the shape retention conductor 40; a step S4 for adjusting the height of the top surface of the electrode body 20 by pushing the electrode body 20 together with the shape retention conductor 40 from the top surface of the electrode body 20; and a step S5 for disposing, while pushing, a conductive plate 30 to the top surface of the electrode body 20 and fixing the edge portion of the conductive plate 30 to a side wall portion 112. The height of the top surface of the electrode body 20 is adjusted so that, when assembling of the electrochemical element 1 is completed, an axial distance d1 between the top surface of the electrode body 20 and the bottom surface of a cover material 12 is greater than an axial distance d2 between the top surface of the electrode body 20 and the top surface of the conductive plate 30.

Description

Electrochemical device assembly method and assembly device

[0001] The present disclosure relates to a manufacturing method and an assembly apparatus for an electrochemical device in which an electrode body is sealed in a case.

[0002] 2. Description of the Related Art A battery has been disclosed in which an electrode assembly is housed in an internal space formed by a recessed container and a lid member that covers the opening of the recessed container.

[0003] Japanese Patent Laid-Open Publication No. 2012-69508 (Patent Document 1) discloses an electrochemical cell with stable electrochemical characteristics. The electrochemical cell has a sealed container. The sealed container is made up of a base member and a lid member. A storage space is formed between the two members to store an electrochemical element (electrode body). An elastic member is disposed between the lid member and the electrochemical element to press against the electrochemical element.

[0004] Furthermore, International Publication No. 2012 / 141231 (Patent Document 2) discloses a solid-state battery capable of maintaining good electrical connection with the electrode layer of a battery body and suppressing deterioration of battery performance. The solid-state battery includes a housing member made of an insulating substrate and a metal cover member, a battery body housed in the housing member, and a current collecting member. The current collecting member is disposed between the housing member and at least one of the positive electrode layer or the negative electrode layer so as to be connected to a conductor portion of the housing member, and is elastic and contains a conductive material.

[0005] JP 2012-69508 A International Publication No. 2012 / 141231

[0006] However, recessed containers, such as the base member of the electrochemical cell of Patent Document 1 and the insulating substrate with a recess in the solid-state battery of Patent Document 2, may have dimensional variations due to manufacturing tolerances. Furthermore, the thickness of the electrode body, such as the electrochemical element of Patent Document 1 and the battery element of Patent Document 2, may also have dimensional variations. When dimensional variations occur in the thickness of the recessed container or electrode body, the thickness of the electrode body becomes excessively large or excessively small relative to the depth of the internal space of the recessed container. Such an error in the thickness of the electrode body relative to the depth of the internal space of the recessed container can cause poor contact between the electrode body and the current collector, etc., resulting in the problem of insufficient battery performance.

[0007] For example, in the electrochemical cell of Patent Document 1, if the thickness of the electrochemical element (electrode body) is too large, i.e., if the height of the upper surface of the electrochemical element placed inside the base member is too high, the electrochemical element may be excessively pressed by the elastic member, resulting in damage and reduced battery performance. Also, if the thickness of the electrochemical element is too small, i.e., if the height of the upper surface of the electrochemical element is too low, sufficient pressing force from the elastic member may not be obtained, resulting in reduced battery performance. Therefore, to obtain sufficient battery performance, it is important to appropriately adjust the height of the upper surface of the electrode body.

[0008] Therefore, an object of the present disclosure is to provide an electrochemical element assembly method and assembly apparatus that can obtain sufficient battery performance by appropriately adjusting the height of the upper surface of the electrode body regardless of dimensional errors in the concave container or electrode body.

[0009] In order to solve the above problems, the present disclosure is configured as follows: That is, a method for assembling an electrochemical element according to the present disclosure includes a recessed container having a bottom and sidewalls, a lid covering an opening of the recessed container, a shape-retaining body arranged between the bottom and the lid in an internal space formed by the recessed container and the lid, an electrode assembly arranged between the lid and the shape-retaining body, and a pressing member arranged between the lid and the electrode assembly and pressing the electrode assembly toward the bottom, and may include the steps of preparing the recessed container, arranging the shape-retaining body on the inner bottom surface of the recessed container, arranging the electrode assembly on the upper surface of the shape-retaining body, and adjusting the height of the upper surface of the electrode assembly by pressing the electrode assembly together with the shape-retaining body from the upper surface of the electrode assembly.

[0010] According to the method for assembling an electrochemical element disclosed herein, an electrochemical element having sufficient battery performance can be obtained by appropriately adjusting the height of the upper surface of the electrode body, regardless of the dimensional error of the concave container or the electrode body.

[0011] Fig. 1 is a flowchart showing a method for assembling an electrochemical device. Fig. 2 is a cross-sectional view showing a first step. Fig. 3 is an external perspective view of the concave container shown in Fig. 2. Fig. 4 is a cross-sectional view showing a second step. Fig. 5 is a cross-sectional view showing a third step. Fig. 6 is a cross-sectional view showing a fourth step. Fig. 7 is a cross-sectional view showing a fifth step. Fig. 8 is an external perspective view of the conductive plate shown in Fig. 7. Fig. 9 is a cross-sectional view showing a sixth step.

[0012] (Configuration 1) A method for assembling an electrochemical element according to an embodiment of the present disclosure is a method for assembling an electrochemical element having a concave container having a bottom and side wall portions, a lid material covering the opening of the concave container, a shape-retaining body arranged between the bottom and the lid material in the internal space formed by the concave container and the lid material, an electrode body arranged between the lid material and the shape-retaining body, and a pressing member arranged between the lid material and the electrode body and pressing the electrode body toward the bottom, and may include the steps of preparing the concave container, arranging the shape-retaining body on the inner bottom surface of the concave container, arranging the electrode body on the upper surface of the shape-retaining body, and adjusting the height of the upper surface of the electrode body by pushing the electrode body together with the shape-retaining body from the upper surface of the electrode body.

[0013] In this way, by flexibly adjusting the height of the upper surface of the electrode assembly using the shape holder, the electrode assembly can be appropriately pressed by the pressing member regardless of dimensional errors of the concave container or the electrode assembly, resulting in an electrochemical device with sufficient battery performance.

[0014] (Configuration 2) The method for assembling an electrochemical element according to Configuration 1 may include a step of adjusting the height of the upper surface of the electrode body by pressing the electrode body, then placing a pressing member on the upper surface of the electrode body while pressing the pressing member, and fixing an end of the pressing member to a side wall of the concave container. This allows the pressing member to come into more stable contact with the electrode body, preventing misalignment due to vibration or the like, and maintaining a good electrical connection.

[0015] (Configuration 3) The method for assembling an electrochemical element according to Configuration 1 or 2 may include a step of fixing an end of a pressing member to a side wall portion of the concave container, and then fixing the lid member to an upper end surface of the side wall portion to seal the internal space. The height of the upper surface of the electrode assembly may be adjusted so that, when assembly of the electrochemical element is completed, the first axial distance between the upper surface of the electrode assembly and the lower surface of the lid member is greater than the second axial distance between the upper surface of the electrode assembly and the upper surface of the pressing member. This allows a gap to be provided between the upper surface of the pressing member and the lid member, and even if a volume change of the electrode assembly causes the pressing member to be pushed toward the lid member, the pressing member and the lid member will not come into contact with each other, thereby suppressing deformation of the lid member.

[0016] (Configuration 4) In the method for assembling an electrochemical element according to any one of configurations 1 to 3, the pressing member may be a conductive plate.

[0017] (Configuration 5) In the method for assembling an electrochemical element according to any one of configurations 1 to 4, the shape-retaining body may be a shape-retaining conductor.

[0018] (Configuration 6) In the method for assembling an electrochemical element according to any one of Configurations 1 to 5, the pressing member according to any one of Configurations 1 to 3 or the conductive plate according to Configuration 4 may include a pressing portion that protrudes from the pressing member or the conductive plate toward the electrode body and presses the electrode body toward the bottom, thereby enabling the pressing member or the conductive plate to more appropriately press the electrode body.

[0019] (Configuration 7) In the method for assembling an electrochemical element according to Configuration 2 or 3, the pressing force applied to the pressing member may be smaller than the pressing force applied to the electrode body. This makes it possible to suppress deformation of the shape holder, which would otherwise result in excessive reduction in thickness, when the pressing member is pressed. As a result, the electrode body is appropriately pressed by the pressing member, maintaining good electrical connection and achieving sufficient battery performance. This also applies when the pressing member is the conductive plate of Configuration 4.

[0020] (Configuration 8) An electrochemical element assembly apparatus according to another embodiment of the present disclosure may be an electrochemical element assembly apparatus used in any one of the electrochemical element assembly methods of Configurations 1 to 8. The assembly apparatus may have a pressing body that presses the electrode body together with the shape retainer from the upper surface of the electrode body. This makes it possible to adjust the height of the upper surface of the electrode body 20.

[0021] Hereinafter, a method for assembling an electrochemical device 1 according to the present disclosure will be specifically described with reference to Figures 1 to 9, taking as an example a case in which the electrochemical device 1 is an all-solid-state battery. Note that identical or corresponding components in the figures are denoted by the same reference numerals, and the same description will not be repeated. Note that, for ease of understanding, the drawings referred to below show simplified or schematic configurations, and some components are omitted.

[0022] (First step S1) First, a hollow container 11 is prepared as shown in Fig. 2. The hollow container 11, together with a lid member 12, constitutes a case for accommodating an electrode assembly 20, which will be described later.

[0023] As shown in FIG. 3 , the recessed container 11 includes a rectangular bottom 111 and a rectangular cylindrical sidewall 112 that is formed continuously from the outer periphery of the bottom 111 and has a cylindrical space therein for accommodating the electrode assembly 20. The sidewall 112 extends substantially perpendicular to the bottom 111 in a longitudinal cross-sectional view. The material of the recessed container 11 is not particularly limited and may be a variety of materials, such as resin, glass (borosilicate glass, glass ceramics, etc.), metal, and ceramics. It may also be a composite material in which ceramic or glass powder is dispersed in resin. When the recessed container 11 is made of a metal material, it is preferable to coat the inner surface of the bottom 111 and the inner circumferential surface of the sidewall 112 of the recessed container 11 with an insulating material such as a resin material or glass to ensure insulation between the recessed container 11 and the electrode assembly 20. Furthermore, the recessed container 11 is not limited to a rectangular shape in a plan view and may be a circular, elliptical, polygonal, or other shape. The internal space for accommodating the electrode body 20 is not limited to a cylindrical shape, but may be formed into a polygonal cylindrical shape such as a rectangular cylindrical shape depending on the shape of the electrode body 20 .

[0024] The side wall portion 112 has multiple support portions 115 that support the conductive plate 30 (described later). In this embodiment, the support portions 115 are protruding portions formed at the upper end of the inner circumferential surface of the side wall portion 112 and protruding along the circumferential direction of the inner circumferential surface. More specifically, as shown in FIG. 3 , the support portions 115 are ceiling walls of multiple recesses formed radially outward on the inner circumferential surface of the side wall portion 112. As a result, the support portions 115 are formed to protrude circumferentially from the inner circumferential surface. The lower surface of each support portion 115, i.e., the lower surface of each ceiling wall, can engage and support a supported portion 31 of the conductive plate 30 (described later) radially outward from the electrode body 20 in a plan view. Furthermore, although two support portions 115 are provided in this embodiment, the number is not limited. For example, if the conductive plate 30 has four supported portions 31, four support portions 115 may be provided at positions corresponding to the supported portions 31.

[0025] A square frame-shaped seal ring 13 is provided on the upper end surface of the side wall portion 112. As will be described later, the lid material 12 is joined (seam welded) to the recessed container 11 by the seal ring 13. This completely seals the internal space of the case. Note that the seal ring 13 does not need to be provided in this first step, and it is sufficient that it is provided on the upper end surface of the side wall portion 112 of the recessed container 11 before the lid material 12, which will be described later, is joined to the recessed container 11.

[0026] (Second step S2) Next, as shown in Fig. 4, the shape-retaining conductor 40 is placed on the inner surface of the bottom 111 of the recessed container 11. At this time, as shown in the figure, the inner surface of the bottom 111 may be formed with a recess into which the shape-retaining conductor 40 can be fitted, so that the positioning of the shape-retaining conductor 40 can be easily performed.

[0027] The shape-retaining conductor 40 is, for example, a porous metal body. After being deformed by a predetermined pressure, the shape-retaining conductor 40 retains its deformed shape. The shape-retaining conductor 40 is not limited to a porous metal body, but may be any conductor that is conductive and can retain its shape after deformation. Alternatively, the shape-retaining conductor 40 is not particularly limited, and may be, for example, a metal member having a spring shape such as a conical spring or a disc spring, or a composite member such as a resin member having a metal film.

[0028] The porous metal body is a porous metal substrate with a high porosity, such as a foamed metal porous body, that has pores penetrating from one surface to the other, and can be compressed by pressing to function as a current collector. After being compressed by pressing, the porous metal body retains its shape after being compressed and deformed.

[0029] The porosity of the porous metal body is preferably 80% or more, and more preferably 90% or more, to make it easier to adjust variations in the thickness of the electrode body 20 due to compression. On the other hand, to ensure good conductivity, the porosity of the porous metal body is preferably 99% or less. The thickness of the porous metal body before assembly into the electrochemical device 1 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more, while preferably 3 mm or less, more preferably 2 mm or less, and particularly preferably 1.5 mm or less.

[0030] The shape-retaining conductor 40 is the shape-retaining body of the present disclosure, and may be any other shape-retaining body as long as it can retain its shape after deformation. For example, the shape-retaining body may be a resin member made only of a resin material as long as it can retain its shape after deformation. Furthermore, the shape-retaining body placed on the inner surface of the bottom 111 of the concave container 11 may be two or more of various shape-retaining bodies, such as a porous metal body, a metal member having a spring shape such as a conical spring or a disc spring, a composite member such as a resin member having a metal film, or a resin member made only of a resin material.

[0031] (Third Step S3) Next, as shown in FIG. 5, the electrode body 20 is placed on the upper surface of the shape-retaining conductor 40.

[0032] The electrode body 20 includes a laminated body in which an electrode layer (positive electrode layer) 21, an electrode layer (negative electrode layer) 22, and a solid electrolyte layer 23 are stacked. The solid electrolyte layer 23 is disposed between the electrode layers 21 and 22 as an isolating layer. That is, in this embodiment, the solid electrolyte layer 23 serves as the isolating layer. The electrode body 20 is formed in a cylindrical shape. The electrode layer 21, the solid electrolyte layer 23, and the electrode layer 22 are stacked in this order from the bottom 111 side (bottom in the figure) of the recessed container 11. That is, the electrode body 20 is housed in the internal space of the case, with the electrode layer 21, which is one end thereof, positioned on the bottom 111 side of the recessed container 11, and the electrode layer 22, which is the other end thereof, positioned on the lid member 12 side. The electrode body 20 is not limited to a cylindrical shape and can be variously modified, such as a rectangular parallelepiped shape or a polygonal prism shape. The electrode body 20 may also include multiple laminated bodies. The plurality of laminates may be stacked so as to be connected in series.

[0033] The electrode layer 21 is a positive electrode pellet formed into a cylindrical shape from a positive electrode mixture containing lithium cobalt oxide, a sulfide-based solid electrolyte, and graphene as a conductive additive in a mass ratio of 65:30:5. The positive electrode active material of the electrode layer 21 is not particularly limited as long as it functions as the positive electrode layer of the electrode body 20. For example, the positive electrode active material may be lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt manganese composite oxide, olivine-type composite oxide, or an appropriate mixture of these. The other components and their proportions are also not particularly limited. The size and shape of the electrode layer 21 are not limited to a cylindrical shape and can be varied depending on the size and shape of the electrochemical device 1.

[0034] The electrode layer 22 is made of LTO (Li ４ Ti ５ O １２The negative electrode pellet is a cylindrically formed negative electrode mixture containing a 50:40:10 weight ratio of lithium titanate (lithium sulphide), a sulfide-based solid electrolyte, and graphene. The negative electrode active material of the electrode layer 22 is not particularly limited as long as it functions as the negative electrode layer of the electrode body 20. For example, it may be metallic lithium, a lithium alloy, a carbon material such as graphite or low-crystalline carbon, or an oxide such as SiO , or an appropriate mixture of these. The other constituent materials and their proportions are also not particularly limited. The size and shape of the electrode layer 22 are not limited to a cylindrical shape and can be varied depending on the size and shape of the electrochemical device 1.

[0035] The solid electrolyte layer (separator layer) 23 contains a sulfide-based solid electrolyte. The solid electrolyte layer 23 is formed into a cylindrical shape. The solid electrolyte contained in the electrode layer 21, the electrode layer 22, and the solid electrolyte layer 23 is not particularly limited, but a sulfide-based solid electrolyte, particularly an argyrodite-type sulfide-based solid electrolyte, is preferably used in terms of ion conductivity. When a sulfide-based solid electrolyte is used, it is preferable to coat the surface of the positive electrode active material with a lithium ion conductive material such as niobium oxide to prevent reaction with the positive electrode active material. The solid electrolyte contained in the solid electrolyte layer 23, the electrode layer 21, and the electrode layer 22 may be a hydride-based solid electrolyte, an oxide-based solid electrolyte, or the like. The size and shape of the solid electrolyte layer 23 are not limited to a cylindrical shape and can be variously changed depending on the size and shape of the electrochemical device 1.

[0036] (Fourth Step S4) Next, as shown in FIG. 6 , the electrode body 20 is pressed together with the shape-retaining conductor 40 from above in the direction of arrow A with a predetermined pressing force. At this time, the shape-retaining conductor 40 is deformed to reduce its thickness by the predetermined pressing force, as shown in the figure. The shape of the deformed shape-retaining conductor 40 is maintained. This allows the height of the upper surface of the electrode body 20 contained in the recessed container 11 to be adjusted. More specifically, as shown in FIG. 9 (described later), the height of the upper surface of the electrode body 20 is adjusted so that, when the assembly of the electrochemical device 1 is complete, the distance (axial distance) d1 in the axial direction CL between the upper surface of the electrode body 20 and the lower surface of the lid member 12 is greater than the distance (axial distance) d2 in the axial direction CL between the upper surface of the electrode body 20 and the upper surface of the conductive plate 30. That is, the height of the upper surface of the electrode body 20 is adjusted so that a gap is formed between the upper surface of the conductive plate 30 and the lower surface of the lid member 12. This makes it possible to suppress deformation of the lid material 12 even when the conductive plate 30 is pressed toward the lid material 12 due to a change in volume of the electrode body 20. Furthermore, the lid material 12 and the recessed container 11 are welded via the seal ring 13 as described above. By providing a gap between the conductive plate 30 and the lid material 12, the effect of welding heat on the electrode body 20 can be suppressed. Furthermore, because the conductive plate 30 and the lid material 12 do not come into contact with each other, the effect of pressure from the conductive plate 30 is eliminated when the lid material 12 is joined to the upper end surface of the side wall portion 112 of the recessed container 11, thereby further improving the sealing performance of the case.

[0037] As shown in FIG. 6 , the electrode body 20 is pressed from above by a presser 100. Therefore, the assembly device for the electrochemical element 1 includes the presser 100. The presser 100 is, for example, an electric cylinder. That is, the electrode body 20 can be pressed together with the shape-retaining conductor 40 by reciprocating a piston housed inside the electric cylinder. The pressing force of the presser 100 is controlled so that the upper surface of the electrode body 20 is at the above-mentioned height. Note that the presser 100 is not limited to an electric cylinder, and is not particularly limited as long as it can adjust the height by pressing the electrode body 20, such as an air cylinder. Furthermore, for example, the presser 100 may have a pressing surface, inside the seal ring 13 in a plan view, that is large enough to abut the upper end surface of the side wall portion 112 and the upper surface of the electrode body 20 from above the recessed container 11, and this pressing surface may be used to press the electrode body 20.

[0038] (Fifth Step S5) Next, as shown in FIG. 7, the conductive plate 30 (pressing member) is pressed onto the upper surface of the electrode body 20 and fixed thereto.

[0039] As shown in FIG. 8 , the conductive plate 30 is a metal plate member having a rectangular shape in a plan view and installed in the opening of the recessed container 11. A plurality of supported portions 31 are formed on the edge of the conductive plate 30, radially outward from the electrode body 20 in a plan view, corresponding to the positions of the respective support portions 115. In this embodiment, the supported portions 31 are hook-shaped engaging pieces that engage with the support portions 115, i.e., the underside of the top wall. More specifically, the supported portions 31 extend from the edge of the conductive plate 30 toward the support portions 115 (downward in FIG. 7 ). The supported portions 31 have tips that are folded back toward the support portions 115, i.e., the underside of the top wall. The conductive plate 30 is supported by the support portions 115 formed on the inner circumferential surface of the recessed container 11 and covers a portion of the opening of the recessed container 11. The area of ​​the conductive plate 30 in a plan view is smaller than the area of ​​the opening of the recessed container 11. Note that even if the hook-shaped locking pieces are not locked to the underside of the top wall, the conductive plate 30 can be fixed in a state in which the hook-shaped locking pieces are press-fit into recesses formed in the inner peripheral surface of the side wall portion 112. Note that the method for fixing the conductive plate 30 to the side wall portion 112 of the recessed container 11 is not particularly limited as long as it can be done. For example, one example of a method for fixing the edge of the conductive plate 30 (supported portion 31) to the inner peripheral surface of the side wall portion 112 of the recessed container 11 is to glue the edge of the conductive plate 30 to the inner peripheral surface of the side wall portion 112 of the recessed container 11.

[0040] As shown in FIG. 7 , the conductive plate 30 has a pressing portion 32 that protrudes from the conductive plate 30 toward the electrode layer 22 of the electrode assembly 20 so as to contact the upper surface of the electrode layer 22, which is the other end of the electrode assembly 20. The shape of the pressing portion 32 is not particularly limited as long as it can press the electrode assembly 20 toward the bottom 111 of the recessed container 11. In this embodiment, the pressing portion 32 is a spring piece (leaf spring) that is inclined from the conductive plate 30 toward the electrode layer 22 of the electrode assembly 20. As shown in FIG. 8 , the pressing portion 32 is formed by cutting out a portion of the conductive plate 30 in a U-shape and is cantilevered by the conductive plate 30. In this way, since it is sufficient to form the pressing portion 32 in a portion of the conductive plate 30, manufacturing the conductive plate 30, i.e., manufacturing the electrochemical element 1, can be easily performed. It is also possible to press the electrode assembly 20 with the lower surface of the conductive plate 30 without providing the pressing portion 32 of this embodiment.

[0041] Examples of metals that make up the conductive plate 30 include nickel, iron, copper, chromium, cobalt, titanium, aluminum, and alloys thereof. In order to facilitate the function of the plate spring, stainless steel for springs such as SUS301-CSP, SUS304-CSP, SUS316-CSP, SUS420J2-CSP, SUS631-CSP, and SUS632J1-CSP are preferably used.

[0042] Furthermore, the thickness of the plate material of the conductive plate 30 is preferably 0.05 mm or more, more preferably 0.07 mm or more, and particularly preferably 0.1 mm or more, in order to ensure a certain level of pressing force on the electrode body 20. On the other hand, in order to prevent the conductive plate 30 from becoming too thick and increasing the storage volume inside the case, and to make the conductive plate 30 easily deformable so that it can be easily engaged with the side wall portion 112, the thickness of the conductive plate 30 is preferably 0.5 mm or less, more preferably 0.4 mm or less, and particularly preferably 0.3 mm or less.

[0043] With the conductive plate 30 placed on the upper surface of the electrode body 20, the tip of the supported portion 31 is positioned between the upper surface of the electrode body 20 and the supporting portion 115, i.e., the lower surface of the top wall, in the axial direction of the electrode body 20 (the up-down direction in FIG. 7 ). Then, the supported portion 31 of the conductive plate 30 is pressed toward the bottom 111 of the recessed container 11, causing the supported portion 31 to be supported by the supporting portion 115. More specifically, the tip of the supported portion 31 is engaged with the supporting portion 115, i.e., the lower surface of the top wall. As the supported portion 31 is pressed downward, the pressing portion 32 of the conductive plate 30 is pressed in the direction opposite the electrode layer 22 while in contact with the electrode body 20. The pressing portion 32 presses the electrode body 20 toward the bottom 111 of the recessed container 11 by its elastic force. This allows the conductive plate 30 to come into more stable contact with the electrode body 20, preventing misalignment due to vibration or the like, and maintaining good electrical connection.

[0044] Furthermore, the pressing force used to press the conductive plate 30 may be smaller than the pressing force used to press the electrode body 20. This prevents deformation of the shape-retaining conductor 40 that would otherwise cause the thickness of the shape-retaining conductor 40 to become excessively thin when the conductive plate 30 is pressed. As a result, the conductive plate 30 presses the electrode body 20 appropriately, maintaining a good electrical connection and achieving sufficient battery performance. Furthermore, damage to the electrode body 20 caused by excessive pressing of the conductive plate 30 can be prevented.

[0045] In addition, the conductive plate 30 is a pressing member in the present disclosure, and may be any other pressing member as long as it is capable of pressing the electrode body 20 and can be fixed at its end to the side wall portion 112 of the concave container 11.

[0046] (Sixth Step S6) Finally, as shown in FIG. 9, the lid member 12 is fixed to the upper end surface of the recessed container 11 via the seal ring 13.

[0047] The lid member 12 is a rectangular metal thin plate that covers the opening of the recessed container 11. As shown in FIG. 9 , the lid member 12 is joined (seam-welded) to the recessed container 11 by a rectangular frame-shaped seal ring 13 disposed between the lower surface of the outer peripheral edge of the lid member 12 and the upper end of the recessed container 11. This completely seals the internal space of the case formed by the recessed container 11 and the lid member 12. The internal space of the case is preferably a vacuum atmosphere or an inert gas atmosphere such as nitrogen, taking into consideration the effect on the electrode assembly 20. Note that the lid member 12 is not limited to a metal thin plate as long as it can cover the opening of the recessed container 11. The shape of the lid member 12 is not limited to a rectangular shape and can be variously modified, such as a circle, an ellipse, or a polygon, depending on the shape of the recessed container 11 in a plan view. The lid member 12 may also have a shape other than a flat plate. Note that the lid member 12 may be bonded to the recessed container 11 with an adhesive, and the method of joining the lid member 12 to the recessed container 11 is not particularly limited as long as it can seal the internal space of the case.

[0048] The electrochemical device 1 assembled in this manner can appropriately press the electrode body 20 with the conductive plate 30. Furthermore, a gap is formed between the upper surface of the electrode body 20 and the lower surface of the lid member 12, thereby suppressing the effects of volumetric changes in the electrode body 20. As a result, sufficient battery performance can be obtained. Although not specifically shown, the electrochemical device 1 has a positive electrode external terminal on the outer surface of the recessed container 11 and a negative electrode external terminal disposed apart from the positive electrode external terminal. A positive electrode conductor is provided inside the recessed container 11. The electrode layer 21 is electrically connected to the positive electrode external terminal via the shape-retaining conductor 40 and the positive electrode conductor. A negative electrode conductor is also provided inside the recessed container 11. The electrode layer 22 is electrically connected to the negative electrode external terminal via the conductive plate 30 and the negative electrode conductor.

[0049] Here, a method for manufacturing the recessed container 11 will be described. First, a metal paste is printed onto a ceramic green sheet to form a printed pattern that will become the positive electrode conductor portion and the negative electrode conductor portion. Next, a plurality of green sheets with these printed patterns are stacked and fired. The support portion 115 described above is formed by stacking a plurality of green sheets with different shapes. This makes it possible to manufacture a recessed container 11 that has positive electrode conductor portions and negative electrode conductor portions therein and the support portion 115 described above on the inner circumferential surface of the side wall portion 112. However, as long as the support portion 115 can be formed on the inner circumferential surface of the side wall portion 112, the manufacturing method is not limited to this. Note that the positive electrode external terminal and the negative electrode external terminal can also be formed by the printed pattern of this metal paste.

[0050] In the above-described embodiment, the electrode layer 21 functions as a positive electrode layer and the electrode layer 22 functions as a negative electrode layer, but the electrode layer 21 may function as a negative electrode layer and the electrode layer 22 may function as a negative electrode layer.

[0051] Furthermore, although the electrode body 20 is configured as a laminate obtained by stacking the electrode layer 21, the electrode layer 22, and the solid electrolyte layer 23, a separator (not shown) may be provided as an isolation layer instead of the solid electrolyte layer 23, and an electrolyte solution may be accommodated together with the electrode body 20 in the internal space of the case, thereby enabling the electrochemical device 1 to be configured as a lithium ion secondary battery, a lithium ion capacitor, an electric double layer capacitor, or the like. In this case, the separator and the electrolyte solution are those typically used in lithium ion secondary batteries, lithium ion capacitors, electric double layer capacitors, or the like. Furthermore, the electrode layers 21 and 22 may be replaced with positive and negative electrode mixture layers typically used in various electrochemical devices 1.

[0052] The present invention can contribute to the achievement of Goal 7 "Affordable and clean energy" and Goal 12 "Responsible consumption and production" of the Sustainable Development Goals (SDGs) advocated by the United Nations.

[0053] Although the embodiments have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0054] REFERENCE SIGNS LIST 1 electrochemical element, 11 concave container, 12 lid material, 13 seal ring, 111 bottom, 112 side wall, 115 support part, 20 electrode body, 30 conductive plate, 31 supported part, 32 pressing part, 100 pressing body

Claims

1. A method for assembling an electrochemical element, comprising a concave container having a bottom and side walls, a lid member covering an opening of the concave container, a shape retainer disposed between the bottom and the lid member in an internal space formed by the concave container and the lid member, an electrode body disposed between the lid member and the shape retainer, and a pressing member disposed between the lid member and the electrode body for pressing the electrode body toward the bottom, the method including the steps of preparing the concave container, disposing the shape retainer on an inner surface of the bottom of the concave container, disposing the electrode body on an upper surface of the shape retainer, and pushing the electrode body together with the shape retainer from the upper surface of the electrode body to adjust the height of the upper surface of the electrode body.

2. The method for assembling an electrochemical element according to claim 1, further including the step of, after pushing the electrode body to adjust the height of the upper surface of the electrode body, disposing the pressing member on the upper surface of the electrode body while pushing it in and fixing an end portion of the pressing member to the side wall of the concave container.

3. The method for assembling an electrochemical element according to claim 2, further including the step of, after fixing the end portion of the pressing member to the side wall of the concave container, fixing the lid member to an upper end surface of the side wall to seal the internal space, wherein the height of the upper surface of the electrode body is adjusted such that a first axial distance between the upper surface of the electrode body and the lower surface of the lid member is greater than a second axial distance between the upper surface of the electrode body and the upper surface of the pressing member when the assembly of the electrochemical element is completed.

4. The method for assembling an electrochemical element according to any one of claims 1 to 3, wherein the pressing member is a conductive plate.

5. The method for assembling an electrochemical element according to any one of claims 1 to 3, wherein the shape retainer is a shape-retaining conductor.

6. The method for assembling an electrochemical element according to any one of claims 1 to 3, wherein the pressing member includes a pressing portion that protrudes from the pressing member toward the electrode body and presses the electrode body toward the bottom.

7. The method for assembling an electrochemical element according to claim 2 or 3, wherein a pressing force for pushing the pressing member is smaller than a pressing force for pushing the electrode body.

8. An electrochemical element assembling apparatus used in the method for assembling an electrochemical element according to any one of claims 1 to 3, wherein the assembling apparatus has a pressing body that presses the electrode body together with the shape retaining body from the upper surface of the electrode body.

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