Electrochemical element

Abstract

Provided is an electrochemical element in which a conductive plate disposed between a power generation element and a cover material can be easily attached and in which good electrical connection can be maintained. An electrochemical element (1) is provided with: a case (10) having a concave container (11) and a lid material (12) for covering the opening of the concave container (11), the concave container (11) being provided with a bottom section (111) and a side wall section (112); a power generation element (20) having a laminate in which an electrode layer (21), an electrode layer (22), and a solid dielectric layer (23) are laminated, the power generation element (20) being housed in the inner space of the case (11) such that a bottom section (111) faces the electrode layer (21); and a conductive plate (30) disposed between the electrode layer (22) and the lid material (12) on the opening side of the recessed container (11). The concave container (11) has a plurality of insertion holes (115) having openings in the upper end surface of the side wall part (112). The conductive plate (30) has a plurality of elastic locking parts (31) at the edge end thereof, the elastic locking parts (31) corresponding to the positions of the insertion holes (115). In a state in which each of the elastic locking sections (31) is inserted into the insertion hole (115), the tip section (311) of the elastic locking section (31) presses the side surface of the insertion hole (115).

Description

Technical Field

[0001] The present disclosure relates to an electrochemical element in which a power generation element is sealed in a housing. Background Art

[0002] Currently, various batteries are disclosed in which a power generating element is accommodated in an internal space formed by a concave container and a cover member covering an opening of the concave container.

[0003] Japanese Patent 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 composed of a base member and a cover member. A storage space for storing an electrochemical element is formed between the two members. An elastic member for pressing the electrochemical element is provided between the cover member and the electrochemical element. In Patent Document 1, as an elastic member, a leaf spring bent in a V-shape when viewed in cross section, or a diaphragm spring formed in a concave curved surface that warps from a central portion toward an outer peripheral edge portion is disclosed.

[0004] In addition, Japanese Patent Publication No. 2010-56067 (Patent Document 2) discloses a coin-type lithium secondary battery, which seals a battery element having a first electrode, a solid dielectric and a second electrode into a container having a metal shell, a metal sealing plate and a gasket sandwiched therebetween, and configures a conductive elastomer between the battery element and the metal shell or the metal sealing plate. The conductive elastomer can press the stack at a pressure of more than 0.1 MPa, and can increase the contact surface pressure between the first electrode and the second electrode and the solid dielectric. As a result, the reduction in current density can be suppressed.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-69508

[0008] Patent Document 2: Japanese Patent Application Publication No. 2010-56067 Summary of the invention

[0009] However, in the electrochemical cell of patent document 1, in the embodiment in which the elastic member presses the electrode body in the state where the position is restricted by the cover member, when the electrochemical cell is sealed, it is necessary to join the cover member with the base member in the state in which the cover member presses the elastic member. Therefore, the cover member is easily tilted by the reaction force from the elastic member, and there is a concern that the joining of the cover member and the base member becomes uneven. In addition, in the case where the elastic member is not fixed to the cover member and the electrode body, there is a concern that the position of the elastic member deviates during sealing. On the other hand, in the embodiment in which the elastic member (diaphragm spring) is fixed to the sealing ring and the base member and the elastic member is separated from the cover member, since the width from the central part to the outer peripheral part in the height direction (the thickness of the entire spring) becomes larger, and the locking position of the spring becomes the outer peripheral part as the upper end in the height direction, so the gap between the elastic member and the cover member is also included, and a large gap is generated between the cover member and the electrochemical element, which becomes the main reason for hindering the high capacity of the electrochemical cell.

[0010] Furthermore, in the coin-type lithium secondary battery of Patent Document 2, the metal casing needs to be riveted in order to generate an appropriate pressing force on the gasket and to press the battery element with a certain pressing force by the conductive elastic body. However, it is difficult to make the thickness of the resin gasket uniform as a whole, and it is difficult to make the gasket generate a uniform pressing force as a whole, and the sealing performance is easily reduced.

[0011] Therefore, an object of the present disclosure is to provide an electrochemical element capable of maintaining good electrical connection.

[0012] In order to solve the above-mentioned problems, the present disclosure is constructed as follows. That is, the electrochemical element of the present disclosure comprises: a housing having a concave container and a cover covering the opening of the concave container, the concave container having a bottom and a side wall; a power generation element, which is sealed in the housing and has a first electrode layer arranged on the bottom side, a second electrode layer arranged on the cover side, and a separator arranged between the first electrode layer and the second electrode layer; and a conductive plate, which is arranged between the power generation element and the cover. The first electrode layer is electrically connected to a first conductive path from the inside of the housing to the outside. The second electrode layer is electrically connected to a second conductive path from the inside of the housing to the outside via the conductive plate. The concave container has an insertion hole having an opening on the upper end surface of the side wall. The conductive plate has an elastic locking portion extending from the edge of the conductive plate and inserted into the insertion hole and used to mount the conductive plate on the above-mentioned concave container. The elastic locking portion inserted into the insertion hole presses the side of the insertion hole.

[0013] According to the electrochemical device of the present disclosure, good electrical connection can be maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional view showing the electrochemical element according to the first embodiment.

[0015] Figure 2 It is shown Figure 1 A three-dimensional view of the appearance of a concave container of an electrochemical element.

[0016] Figure 3 It is shown Figure 1 A top view of an electrochemical element (excluding the cover material and the conductive plate).

[0017] Figure 4 It is shown Figure 1 A top view of the conductive plates of an electrochemical element.

[0018] Figure 5 It is shown Figure 1 A perspective view of the appearance of a modified example of the conductive plate of the electrochemical element.

[0019] Figure 6 It is a cross-sectional view showing an electrochemical device according to a second embodiment.

[0020] Figure 7 It is a cross-sectional view showing an electrochemical device according to a third embodiment.

[0021] Figure 8 It is a cross-sectional view showing an electrochemical device according to a fourth embodiment.

[0022] Fig. 9 This is a perspective view showing the appearance of a concave container of an electrochemical device according to Modification 1.

[0023] Fig.10 1 is a perspective view showing the appearance of a conductive plate according to Modification 2.

[0024] Fig.11 is shown with Fig.10 A three-dimensional view of the appearance of a concave container corresponding to the conductive plate shown.

[0025] Fig.12 This is a perspective view showing the appearance of a concave container of an electrochemical device according to Modification 3.

[0026] Fig.13 This is a cross-sectional view showing an electrochemical device according to Modification 4.

[0027] Fig.14 This is a perspective view showing the appearance of a concave container according to Modification Example 6. DETAILED DESCRIPTION

[0028] (Structure 1)

[0029] The electrochemical element of the embodiment of the present disclosure preferably comprises: a housing having a concave container and a cover material covering the opening of the concave container, the concave container having a bottom and a side wall; a power generation element sealed in the housing, having a first electrode layer arranged on the bottom side, a second electrode layer arranged on the cover material side, and a separator arranged between the first electrode layer and the second electrode layer; and a conductive plate arranged between the power generation element and the cover material. The first electrode layer is preferably electrically connected to a first conductive path from the inside of the housing to the outside. The second electrode layer is preferably electrically connected to a second conductive path from the inside of the housing to the outside via the conductive plate. The concave container preferably has an insertion hole having an opening on the upper end surface of the side wall. The conductive plate preferably has an elastic locking portion extending from the edge of the conductive plate and inserted into the insertion hole and used to mount the conductive plate on the concave container. The elastic locking portion inserted into the insertion hole preferably presses the side of the insertion hole.

[0030] Thus, the conductive plate is fixed to the concave container by the elastic force of the elastic locking portion, thereby maintaining good electrical connection. In addition, since the elastic locking portion can be inserted from the upper end surface of the concave container toward the insertion hole, the conductive plate can be easily installed in the concave container.

[0031] (Structure 2)

[0032] In the electrochemical element of structure 1, the elastic locking portion preferably has a front end portion that is folded back in a direction opposite to the insertion direction of the insertion hole. Thus, the elastic locking portion can be easily inserted into the insertion hole, and since the front end portion presses the side surface of the insertion hole and fixes the conductive plate to the concave container, a good electrical connection can be maintained.

[0033] (Structure 3)

[0034] In the electrochemical element of structure 1, the elastic locking portion preferably has a corrugated plate shape. Thus, when the elastic locking portion is inserted into the insertion hole, each curved surface of the corrugated plate shape is pressed by the side surface of the insertion hole and bends in a manner extending in the insertion direction, and the side surface of the insertion hole is pressed by the elastic force. As a result, the conductive plate can be easily fixed to the concave container 11, and a good electrical connection can be maintained.

[0035] (Structure 4)

[0036] In the electrochemical element of structure 1, it is preferable to form a gap between the conductive plate and the cover material. As a result, the cover material does not abut against the power generation element, so when the cover material is joined to the upper end surface of the side wall of the concave container, it will not be affected by the thickness deviation of the power generation element, etc., and the sealing performance of the outer shell can be improved.

[0037] (Structure 5)

[0038] The electrochemical element of another embodiment preferably comprises: a housing having a concave container and a cover material covering the opening of the concave container, the concave container having a bottom and a side wall; a flat element having an outer packaging material and a power generation element, the outer packaging material being sealed in the housing and including a first electrode terminal arranged on the bottom side and a second electrode terminal arranged on the cover material side, the power generation element being sealed inside the outer packaging material and including a first electrode layer, a second electrode layer, and a separator arranged between the first electrode layer and the second electrode layer; and a conductive plate arranged between the flat element and the cover material. The first electrode terminal is preferably electrically connected to a first conductive path from the inside of the housing to the outside. The second electrode terminal is preferably electrically connected to a second conductive path from the inside of the housing to the outside via the conductive plate. The concave container preferably has an insertion hole having an opening on the upper end surface of the side wall. The conductive plate preferably has an elastic locking portion extending from the edge of the conductive plate and inserted into the insertion hole and used to attach the conductive plate to the concave container. The elastic locking portion inserted into the insertion hole preferably presses the side of the insertion hole. Thus, the conductive plate is fixed to the concave container by the elastic force of the elastic locking portion, so that a good electrical connection can be maintained. In addition, the elastic locking portion can be inserted from above the upper end surface of the concave container toward the insertion hole, so the conductive plate can be easily installed in the concave container.

[0039] In the following, taking the case where the electrochemical element is an all-solid-state battery as an example, Figure 1 to Figure 5 The first embodiment of the present disclosure is described in detail. Figure 1 As shown, the electrochemical element 1 includes a case 10 , a power generation element 20 and a conductive plate 30 housed in the case 10 , and external terminals 13 and 14 disposed on the outer surface of the case 10 .

[0040] The housing 10 has a concave container 11 and a cover material 12. The concave container 11 is made of ceramic. The concave container 11 includes a quadrilateral bottom 111 and a square cylindrical side wall portion 112, which is continuously formed from the outer periphery of the bottom 111 and has a cylindrical space inside for accommodating the power generation element 20. The side wall portion 112 is extended approximately perpendicular to the bottom 111 when longitudinally sectioned. A conductor portion 113 is formed inside the bottom 111. The conductor portion 113 extends between the power generation element 20 and the bottom 111 in a manner electrically connected to the power generation element 20, forming a conduction path corresponding to the electrode layer 21. A conductor portion 114 is formed inside the side wall portion 112. As Figure 1As shown, a portion of the conductor portion 114 is formed to be exposed on the lower surface or side surface of the insertion hole 115 described below, forming a conductive path corresponding to the electrode layer 22. The manufacturing method of the concave container 11 is described below. In addition, the material of the concave container 11 is not particularly limited, and various materials such as resin, glass (borosilicate glass, glass ceramics, etc.), metal and ceramic can be exemplified. It can also be a composite material in which ceramic or glass powder is dispersed in a resin. In the case where the concave container 11 is composed of a metal material, in order to ensure the insulation between the concave container 11 and the power generation element 20, or the concave container 11 and the flat element 50 described below (see Figure 8 . ) In order to provide insulation, it is preferred to cover the inner surface of the bottom 111 of the concave container 11 and the inner circumferential surface of the side wall 112 with an insulating material such as a resin material or glass. Furthermore, the concave container 11 is not limited to being a quadrilateral when viewed from above, but may also be circular, elliptical, or polygonal. The internal space for accommodating the power generation element 20 is not limited to a cylindrical shape, but may also be formed into a polygonal cylindrical shape such as a square cylinder shape according to the shape of the power generation element 20. Furthermore, the conductor portion 114 may be formed on the inner surface of the side wall portion 112 instead of being formed inside the side wall portion 112, and pass through the interior of the bottom 111 to be conductive with the external terminal 14. In this case, it is preferred to form an insulating layer between the outer circumferential surface of the power generation element 20 and the conductor portion 114, for example, on the inner surface of the conductor portion 114, so that the outer circumferential surface of the power generation element 20 and the conductor portion 114 do not contact each other.

[0041] The side wall portion 112 has an insertion hole 115 at the upper end surface of the side wall portion 112 into which the elastic locking portion 31 of the conductive plate 30 described below is inserted. The insertion hole 115 has an opening at the upper end surface of the side wall portion 112. The depth of the insertion hole 115 is not particularly limited, and the depth that can insert the elastic locking portion 31 is sufficient. In addition, the width of one side surface of the insertion hole 115 and the other side surface opposite to the one side surface is smaller than the width of the elastic locking portion 31 before being inserted into the insertion hole 115. That is, as described below, the elastic locking portion 31 is inserted into the insertion hole 115 while shrinking and deforming, and presses one and the other side surfaces of the insertion hole 115 with its elastic force. In this embodiment, four insertion holes 115 are formed on the upper end surface of the side wall portion 112. The insertion holes 115 are formed in the same number as the elastic locking portion 31 at a position corresponding to the elastic locking portion 31.

[0042] The cover material 12 is a rectangular metal thin plate that covers the opening of the concave container 11. Figure 1 and Figure 3As shown, the cover material 12 is joined (seam welded) to the concave container 11 by a square frame-shaped sealing ring 15 disposed between the lower surface of its outer peripheral end and the upper end of the concave container 11. As a result, the internal space of the outer shell 10 is completely closed. Considering the influence on the power generation element 20, the internal space of the outer shell 10 is preferably a vacuum atmosphere or an inert gas atmosphere such as nitrogen. In addition, the cover material 12 can cover the opening of the concave container 11 and is not limited to a metal thin plate. The cover material 12 is not limited to a quadrilateral and can be changed to various shapes such as a circle, an ellipse, and a polygon according to the shape of the concave container 11 when viewed from above. In addition, the cover material 12 can also be a shape other than a flat plate. In addition, the cover material 12 can also be bonded to the concave container 11 by an adhesive, and it can seal the internal space of the outer shell 10. The method of joining the cover material 12 to the concave container 11 is not particularly limited.

[0043] The external terminal 13 is arranged on the outer surface of the bottom 111 of the concave container 11. The external terminal 13 is electrically connected to the electrode layer 21 described below via the conductor portion 113. The electrode layer 21 functions as a positive electrode layer as described below. Therefore, the conductor portion 113 becomes a conduction path that connects the external terminal 13 and the positive electrode layer, and the external terminal 13 functions as a positive electrode terminal.

[0044] The external terminal 14 is arranged on the outer surface of the bottom 111 of the concave container 11 in a manner separated from the external terminal 13. The external terminal 14 is electrically connected to the elastic locking portion 31 of the conductive plate 30 described below via the conductor portion 114. As described below, the conductive plate 30 is electrically connected to the electrode layer 22 that functions as a negative electrode layer. Therefore, the conductor portion 114 becomes a conduction path that allows the external terminal 14 to be conductive with the negative electrode layer, and the conductive plate 30 becomes a connection terminal that allows the conduction path to be conductive with the electrode layer 22, so that the external terminal 14 functions as a negative electrode terminal. In addition, the arrangement of the external terminal 13 and the external terminal 14 is not limited to the above case, and can also be arranged on the outer surface of the side wall portion 112 of the concave container 11, and the cover material 12 can also function as the conductor portion 114, and the external terminal 14 can be formed on the outer surface of the cover material 12. Among them, the two terminals are arranged on the outer surface of the bottom 111 of the concave container 11 in a manner of setting a certain interval, so that it becomes easy to install on the surface of the circuit substrate.

[0045] Here, the manufacturing method of the concave container 11 is described. First, a metal paste is printed and applied on a ceramic green sheet to form a printed pattern of the conductor part 113 and the conductor part 114. Then, a plurality of green sheets formed with the above-mentioned printed pattern are stacked and fired. The above-mentioned insertion hole 115 is formed by stacking a plurality of green sheets of different shapes. In this way, a concave container 11 having the conductor part 113 and the conductor part 114 inside and the insertion hole 115 on the upper end surface of the side wall part 112 can be manufactured. In addition, the insertion hole 115 can be formed on the upper end surface of the side wall part 112, and the manufacturing method is not limited to this. In addition, the external terminal 13 and the external terminal 14 can also be formed by the printed pattern of the metal paste.

[0046] The power generation element 20 includes a stacked 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 arranged between the electrode layer 21 and the electrode layer 22 as a separator. That is, in the present embodiment, the separator is the solid electrolyte layer 23. The power generation element 20 is formed in a cylindrical shape. The power generation element 20 is stacked with the electrode layer 21, the solid electrolyte layer 23, and the electrode layer 22 in order from the bottom 111 side of the concave container 11 (the lower side in the figure). That is, the power generation element 20 is arranged in a manner that the electrode layer 21 as one end thereof becomes the bottom 111 side of the concave container 11, and the electrode layer 22 as the other end thereof becomes the cover material 12 side, and is stored in the internal space of the housing 10. In addition, the power generation element 20 is not limited to a cylindrical shape, and can be changed to various shapes such as a rectangular parallelepiped shape and a polygonal column shape. In addition, the power generation element 20 may also have a plurality of stacked bodies. A plurality of stacked bodies may be stacked so as to be connected in series.

[0047] The electrode layer 21 is a positive electrode particle formed into a cylindrical shape by placing a positive electrode mixture containing lithium cobalt oxide, a sulfide-based solid electrolyte, and graphene as a conductive aid in a mass ratio of 65:30:5 into a mold with a diameter of 7.45 mm. In addition, the positive electrode active material of the electrode layer 21 can function as a positive electrode layer of the power generation element 20 without any special limitation. For example, it can be lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt manganese composite oxide, olivine-type composite oxide, etc., or a material appropriately mixed therewith. Other constituent materials and proportions are not particularly limited. In addition, the size and shape of the electrode layer 21 are not limited to a cylindrical shape, and various changes can be made according to the size and shape of the electrochemical element 1.

[0048] The electrode layer 22 is a negative electrode active material used in lithium ion secondary batteries, and contains LTO (Li4Ti5O 12, lithium titanate), sulfide-based solid electrolyte, and graphene negative electrode mixture formed into cylindrical negative electrode particles. In addition, the negative electrode active material of the electrode layer 22 can function as the negative electrode layer of the power generation element 20 without any special limitation. For example, in addition to metallic lithium and lithium alloys, it can be carbon materials such as graphite, low-crystalline carbon, oxides such as SiO, etc., or a material appropriately mixed therewith. Other constituent materials and proportions are not particularly limited. In addition, the size and shape of the electrode layer 22 are not limited to a cylindrical shape, and various changes can be made according to the size and shape of the electrochemical element 1.

[0049] The solid electrolyte layer (separating layer) 23 includes a sulfide-based solid electrolyte. The solid electrolyte layer 23 is formed into a cylindrical shape. In addition, the solid electrolyte contained in the electrode layer 21, the electrode layer 22 and the solid electrolyte layer 23 is not particularly limited. From the perspective of ion conductivity, it is preferred to use a sulfide-based solid electrolyte, especially a sulfide-based solid electrolyte of the argyrodite type. In the case of using a sulfide-based solid electrolyte, in order to prevent reaction with the positive electrode active material, it is preferred to coat the surface of the positive electrode active material with a lithium ion conductive material such as niobium oxide. In addition, the solid electrolyte contained in the solid electrolyte layer 23, the electrode layer 21 and the electrode layer 22 may also be a hydride-based solid electrolyte, an oxide-based solid electrolyte, etc. In addition, the size and shape of the solid electrolyte layer 23 are not limited to a cylindrical shape, and various changes can be made according to the size and shape of the electrochemical element 1.

[0050] like Figure 1 and Figure 4 As shown in FIG. 1 , the conductive plate 30 is a metal plate in a plan view provided at the opening of the concave container 11 of the housing 10. The conductive plate 30 has four elastic locking portions 31 at its edge and at positions corresponding to the respective insertion holes 115. The number of the elastic locking portions 31 is not limited and can be determined according to the number of the insertion holes 115. The plan view shape of the conductive plate 30 is not particularly limited and can be Figure 4 For example, when the conductive plate 30 has four elastic locking portions 31, the conductive plate 30 may be a quadrilateral in a plan view, and when the conductive plate 30 has two elastic locking portions 31, the conductive plate 30 may be a circle in a plan view. In this embodiment, the elastic locking portions 31 extend from the edge of the conductive plate 30 toward the insertion hole 115 (towards Figure 1 The elastic locking portion 31 has a front end portion 311 that is folded back in the direction opposite to the direction in which the elastic locking portion 31 is inserted into the insertion hole 115. The front end portion 311 is folded back in the radial direction. In addition, the front end portion 311 may also be folded back in the radial direction. Figure 1As shown, in a longitudinal section taken along the folded direction of the front end portion 311 in a top view, the width between one side of the insertion hole 115 and the other side opposite to the one side is smaller than the width of the elastic locking portion 31 before being inserted into the insertion hole 115. Therefore, the elastic locking portion 31 is inserted into the insertion hole 115 while being bent in a manner that the folded front end portion 311 is further bent toward the elastic locking portion 31. After being inserted into the insertion hole 115, the front end of the front end portion 311 presses the side of the insertion hole 115 by its elastic force. Thus, the conductive plate 30 is fixed to the concave container 11. In this way, in the electrochemical element 1, it is sufficient to insert the elastic locking portion 31 into the insertion hole 115, so that the conductive plate 30 can be easily installed in the concave container 11. In addition, since the conductive plate 30 is fixed to the concave container 11 by the elastic force of the elastic locking portion 31, a good electrical connection can be maintained. Furthermore, the elastic locking portion 31, when inserted into the insertion hole 115, contacts the conductor portion 114 exposed on a portion of the lower surface or side surface of the insertion hole 115. Thus, the conductive plate 30 functions as a current collector and functions as a connection terminal that electrically connects the electrode layer 22 and the conduction path connected to the external terminal 14. The conductive plate 30 covers a portion of the opening of the concave container 11. The area of ​​the conductive plate 30 when viewed from above is smaller than the opening area of ​​the concave container 11.

[0051] like Figure 1 As shown, the conductive plate 30 has a concave portion that is concave toward the electrode layer 22 at the contact position with the other end of the power generation element 20, that is, the upper surface of the electrode layer 22. The bottom surface 32 of the concave portion is formed in a flat shape so that the power generation element 20 can be pressed with a larger area. In addition, the periphery of the bottom surface 32 of the concave portion forms a step portion 33 that is displaced in the thickness direction. The step portion 33 is a circumferential wall of a truncated cone whose diameter gradually decreases toward the power generation element 20. As shown in FIG. Figure 1 As shown, the bottom surface 32 of the recess is opposite to the electrode layer 22 and is in contact with the upper surface of the electrode layer 22. In this way, the planar bottom surface 32 presses the electrode layer 22 with a large area, thereby suppressing the damage of the electrode layer 22 when the power generation element 20 expands. In addition, since a larger contact area between the conductive plate 30 and the power generation element 20 is ensured, the conductive connection between the conductive plate 30 and the power generation element 20 is carried out with a larger area, and a further good electrical connection can be maintained. In addition, by providing the step portion 33, the overall thickness of the conductive plate 30 can be made thinner. Furthermore, the position of the edge of the conductive plate 30, that is, the elastic locking portion 31, can be freely set in the height direction (the thickness direction of the conductive plate), so even if a gap is formed between the cover material 12 and the conductive plate 30, the distance between the cover material 12 and the bottom surface 32 of the conductive plate 30 will not increase. As a result, the gap between the cover material 12 and the power generation element 20 can be suppressed from increasing, so that the capacity of the electrochemical element 1 can be increased. In addition, the thickness direction refers to Figure 1The up-down direction (the height direction of the electrochemical element 1 ) can also be said to be a direction perpendicular to the bottom surface 32 in the figure.

[0052] Examples of the metal constituting the conductive plate 30 include nickel, iron, copper, chromium, cobalt, titanium, aluminum and alloys thereof. In order to easily function as a leaf spring, it is preferred to use spring stainless steel such as SUS301-CSP, SUS304-CSP, SUS316-CSP, SUS420J2-CSP, SUS631-CSP and SUS632J1-CSP.

[0053] Furthermore, in order to make the pressing force on the power generation element 20 be above a certain level, the thickness 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. On the other hand, in order to prevent the conductive plate 30 from becoming too thick and increasing the storage volume in the housing 10, and to make the conductive plate 30 easily deformable and easily fixed to 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.

[0054] In order to reduce the contact resistance, the area of ​​the bottom surface 32 of the conductive plate 30 is preferably 10% or more of the area of ​​the electrode layer 22 of the opposing power generation element 20 when viewed from above, more preferably 30% or more, particularly preferably 50% or more, and most preferably 60% or more. On the other hand, in order to reduce the radial gap around the power generation element 20, the area of ​​the bottom surface 32 of the conductive plate 30 is preferably 100% or less of the area of ​​the electrode layer 22 of the opposing power generation element 20 when viewed from above, more preferably 95% or less, particularly preferably 90% or less, and most preferably 85% or less. In addition, the shape of the bottom surface 32 of the conductive plate 30 may not be a completely flat surface, and in order to reduce the contact resistance with the power generation element 20, it may be a surface with projections and depressions such as embossing.

[0055] After the power generating element 20 is stored inside the concave container 11, the conductive plate 30 is placed on the upper surface of the power generating element 20. After the elastic locking portion 31 is aligned with the position of the insertion hole 115 when viewed from above, the elastic locking portion 31 of the conductive plate 30 is pressed into the insertion hole 115, thereby attaching and fixing the conductive plate 30 to the concave container 11. After the bottom surface 32 of the conductive plate 30 is in contact with the power generating element 20, the conductive plate 30 is further pressed downward. As a result, the conductive plate 30 is slightly bent in the direction opposite to the electrode layer 22 in a state of contact with the power generating element 20. The conductive plate 30 presses the power generating element 20 in the direction of the bottom 111 of the concave container 11 by its elastic force. As a result, the conductive plate 30 and the power generating element 20 are in contact more stably, and positional deviation due to vibration or the like does not occur, and good electrical connection can be maintained. At this time, since the above-mentioned concave portion is formed in the conductive plate 30, the influence of the bending on the flat bottom surface 32 is reduced, so that the electrical connection can be maintained more well. Thus, the conductive plate 30 has the step portion 33, but the structure is not particularly limited as long as the elastic locking portion 31 is inserted into the insertion hole 115 to press the power generating element 20 toward the bottom 111 of the concave container 11. For example, the conductive plate 30 may also have a spring piece 34 that rises from the conductive plate 30 toward the electrode layer 22 of the power generating element 20 so as to contact the upper surface of the electrode layer 22 of the power generating element 20. Figure 5 As shown, the spring piece 34 may also be formed by cutting the conductive plate 30 in the vicinity of the center in a plan view into a "U" shape, with the front end thereof inclined toward the electrode layer 22. Figure 5 The conductive plate 30 is as follows Fig.10 Therefore, the front end portion 311 of the elastic locking portion 31 may also be folded back in the circumferential direction relative to the inner circumference of the concave container 11. The shape, number and arrangement position of the spring piece 34 are not particularly limited as long as they can press the power generation element 20 in the direction of the bottom 111 of the concave container 11.

[0056] A gap is formed between the conductive plate 30 and the cover material 12. That is, the conductive plate 30 is not in contact with the cover material 12. Thus, even when the conductive plate 30 is pushed toward the cover material 12 due to a volume change of the power generation element 20, deformation of the cover material 12 can be suppressed. Furthermore, as described above, the cover material 12 and the concave container 11 are welded via the sealing ring 15. Since a gap is provided between the conductive plate 30 and the cover material 12, the influence of welding heat on the power generation element 20 can be suppressed. Furthermore, since the conductive plate 30 is not in contact with the cover material 12, when the cover material 12 is joined to the upper end surface of the side wall portion 112 of the concave container 11, it will not be affected by the volume change of the power generation element 20, and the sealing performance of the outer casing 10 can be further improved.

[0057] (Second embodiment)

[0058] Next, use Figure 6 , the electrochemical device 1 of the second embodiment will be specifically described. In the electrochemical device 1 of this embodiment, the description of the same structure as the electrochemical device 1 of the first embodiment is basically omitted, and only the structure different from the electrochemical device 1 of the first embodiment will be described.

[0059] In the electrochemical element 1 of the present embodiment, the power generation element 20 has a porous metal layer 24. The porous metal layer 24 is formed on the surface of the electrode layer 22. That is, the power generation element 20 has the porous metal layer 24 formed between the electrode layer 22 and the conductive plate 30. The porous metal layer 24 is in contact with the bottom surface 32 of the conductive plate 30.

[0060] The porous metal layer 24 is a porous metal matrix with a high porosity and pores extending from one surface to another, like a foamed metal porous body, and can be pressed and compressed to function as a current collector. The porous metal layer 24 covers the surface of the electrode layer 22. In order to reduce the resistance, the porous metal layer 24 is preferably not only in contact with the electrode layer 22, but also a part of the negative electrode mixture buried in the electrode layer 22 is formed integrally with the electrode layer 22. In addition, as Figure 6 As shown, on the lower surface of the electrode layer 22, i.e., the bottom 111 side, a porous metal layer 24 may be arranged on the surface of the electrode layer 21, or the porous metal layer 24 may be arranged in a manner such that a positive electrode mixture partially embedded in the electrode layer 21 is integrated with the electrode layer 21.

[0061] In order to easily adjust the deviation of the thickness of the power generation element 20 caused by compression, the porosity of the porous metal layer 24 is preferably 80% or more, more preferably 90% or more. On the other hand, in order to ensure good conductivity, the porosity of the porous metal layer 24 is preferably 99% or less. The thickness of the porous metal layer 24 before assembling the electrochemical element 1 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more. On the other hand, it is preferably 3 mm or less, more preferably 2 mm or less, and particularly preferably 1.5 mm or less.

[0062] By providing the porous metal layer 24 in this way, the variation of the thickness of the power generation element 20 or the height of the housing 10 can be fully absorbed, and as a result, the variation of the value of the internal resistance can be suppressed. Alternatively, when the porous metal layer 24 is formed integrally with the second electrode layer in advance, the resistance of the conductive portion between the bottom surface 32 of the conductive plate 30 or the spring piece and the power generation element 20 can be reduced.

[0063] (Third Embodiment)

[0064] Next, use Figure 7, the electrochemical device 1 of the third embodiment will be specifically described. In the electrochemical device 1 of this embodiment, the description of the same structure as the electrochemical device 1 of the first embodiment is basically omitted, and only the structure different from the electrochemical device 1 of the first embodiment will be described.

[0065] The electrochemical element 1 of the present embodiment has a conductive sheet 40 between the electrode layer 22 and the conductive plate 30. In the present embodiment, the conductive sheet 40 is a conductive carbon sheet composed of expanded graphite, that is, a graphite sheet. The graphite sheet is manufactured as follows. First, the particles of acid-treated graphite after acid treatment of natural graphite are heated. In this way, the acid-treated graphite expands due to the gasification of the acid located between its layers. The expanded graphite (expanded graphite) is formed into a felt shape and then rolled using a roller mill to form a sheet. The conductive sheet 40 is manufactured by digging the sheet of the expanded graphite into a circular shape. As described above, the expanded graphite is formed by the acid gasification and the acid-treated graphite foaming. Therefore, the graphite sheet is formed into a porous shape. Therefore, the graphite sheet has the conductivity of the graphite itself, and also has the softness that the graphite products of the prior art do not have. In addition, the method for manufacturing the graphite sheet is not limited to this, and it can also be composed of materials other than expanded graphite, and the graphite sheet can also be manufactured by any method.

[0066] The apparent density of the graphite sheet is preferably 0.3 g / cm 3 More preferably 0.7 g / cm 3 Above, and preferably 1.5 g / cm 3 Below, more preferably 1.3 g / cm 3 This is because if the apparent density of the graphite sheet is too low, the graphite sheet is easily damaged, and if the apparent density is too high, the softness is reduced. In addition, the apparent density is not limited to the graphite sheet, and can also be applied to the conductive sheet 40 formed of other materials such as conductive tape.

[0067] The thickness of the graphite sheet is preferably 0.05 mm or more, more preferably 0.07 mm or more, and preferably 0.5 mm or less, more preferably 0.2 mm or less. This is because if the thickness of the graphite sheet is too small, the graphite sheet is easily damaged, and if the thickness is too large, the graphite sheet reduces the internal space of the housing 10 that accommodates the power generation element 20, and the volume (thickness) of the power generation element 20 that can be accommodated is reduced. In addition, the thickness of the graphite sheet is not limited to the graphite sheet, and can also be applied to the conductive sheet 40 formed of other materials such as conductive tape and metal.

[0068] Thus, by providing a conductive sheet 40 that is more flexible than the conductive plate 30, i.e., easily deformable, the pressing force of the conductive plate 30 is more evenly transmitted to the power generating element 20, which can suppress damage to the power generating element 20 and achieve stable electrical connection. Figure 7As shown, the conductive sheet 40 is disposed between the electrode layer 21 and the bottom 111 of the concave container 11. This can further suppress damage to the power generating element 20 and stabilize electrical connection.

[0069] (Fourth Embodiment)

[0070] Next, use Figure 8 , specifically, the electrochemical element 1 of the fourth embodiment is described. In the electrochemical element 1 of this embodiment, the description of the same structure as the electrochemical element 1 of the first and second embodiments is basically omitted, and only the structure different from the electrochemical element 1 of the first and second embodiments is described.

[0071] The electrochemical element 1 of this embodiment contains a flat element 50 in the inner space of the casing 10. Figure 8 As shown, the flat element 50 includes an outer can (electrode terminal) 51 , a sealing can (electrode terminal) 52 , the above-mentioned power generation element 20 , and a gasket 53 .

[0072] The outer can 51 includes a circular plane portion 511 and a cylindrical side wall portion 512 formed continuously from the outer periphery of the plane portion 511. The cylindrical side wall portion 512 is provided to extend substantially perpendicularly to the plane portion 511 when longitudinally sectioned. The outer can 51 is formed of a metal material such as stainless steel. The outer can 51 is arranged on the bottom 111 side of the concave container 11.

[0073] The sealing can 52 includes a circular plane portion 521 and a cylindrical peripheral wall portion 522 formed continuously from the outer periphery of the plane portion 521. The opening of the sealing can 52 is opposite to the opening of the outer can 51. The sealing can 52 is formed of a metal material such as stainless steel. The sealing can 52 is arranged on the side of the cover material 12. The power generation element 20 is accommodated between the outer can 51 and the sealing can 52. Therefore, the outer can 51 functions as an electrode terminal connected to the conductor portion 113, and the sealing can 52 functions as another electrode terminal connected to the conductive plate 30.

[0074] After the power generation element 20 is stored in the internal space of the outer can 51 and the sealing can 52, the cylindrical side wall portion 512 of the outer can 51 and the peripheral wall portion 522 of the sealing can 52 are riveted via the gasket 53. More specifically, the outer can 51 and the sealing can 52 are placed with their openings facing each other, and the peripheral wall portion 522 of the sealing can 52 is inserted into the inner side of the cylindrical side wall portion 512 of the outer can 51, and then the cylindrical side wall portion 512 and the peripheral wall portion 522 are riveted via the gasket 53. Thus, the internal space formed by the outer can 51 and the sealing can 52 is closed. That is, the outer can 51 and the sealing can 52 are outer packaging materials that seal the power generation element 20 in their internal space. In addition, the outer can 51 and the sealing can 52 are not limited to being circular in plan view, and can be changed to various shapes such as elliptical or polygonal.

[0075] The gasket 53 is made of a resin material such as a polyamide resin, a polypropylene resin, or a polyphenylene sulfide resin. In addition, the method of setting the internal space formed by the outer can 51 and the sealing can 52 to a closed state is not limited to riveting via the gasket 53, and other methods may be used. For example, a hot melt resin, an adhesive, etc. may be interposed between the cylindrical side wall portion 512 of the outer can 51 and the peripheral wall portion 522 of the sealing can 52 to perform bonding and sealing.

[0076] After the flat element 50 is accommodated in the concave container 11, the conductive plate 30 is placed on the upper surface of the flat element 50, and the elastic locking portion 31 is locked in the insertion hole 115 for fixing. At this time, after the bottom surface 32 contacts the flat surface portion 521 of the sealing can 52, the conductive plate 30 is further pressed downward, and the conductive plate 30 is slightly bent in the direction opposite to the flat element 50. The conductive plate 30 uses its elastic force to press the flat element 50 in the direction of the bottom 111 of the concave container 11. As a result, the conductive plate 30 and the flat element 50 are in contact more stably, and similar to the electrochemical element 1 of the first embodiment, positional deviation due to vibration or the like does not occur, and good electrical connection can be maintained.

[0077] In the electrochemical element 1 of this embodiment, although not particularly shown, the porous metal layer 24 or the conductive sheet 40 described above may be disposed between the flat element 50 and the conductive plate 30. Furthermore, the porous metal layer 24 or the conductive sheet 40 may be disposed between the flat element 50 and the bottom 111 of the concave container 11.

[0078] The flat element 50 is not limited to an all-solid battery having a solid electrolyte layer, and may be a non-aqueous electrolyte battery such as a lithium ion secondary battery, another flat battery, or a capacitor such as a lithium ion capacitor.

[0079] (Variant 1)

[0080] like Fig. 9 As shown, the concave container 11 of the modification 1 has two insertion holes 115. In this case, the number of the elastic locking parts 31 formed on the conductive plate 30 is two. Thus, in the electrochemical element 1 of each embodiment, the number of the insertion holes 115 is not limited, and a plurality of insertion holes 115 may be formed in a manner that a plurality of elastic locking parts 31 can be respectively inserted.

[0081] (Variant 2)

[0082] like Fig.10 As shown, the front end portion 311 of the elastic locking portion 31 may also be folded back in the circumferential direction relative to the inner circumferential surface of the concave container 11 instead of being folded back in the radial direction. Fig.11 As shown, the insertion hole 115 formed at the upper end of the side wall portion 112 of the concave container 11 is formed so that the elastic locking portion 31 can be inserted, and after the elastic locking portion 31 is inserted, the front end portion 311 can press the side of the insertion hole 115 by the elastic force of the elastic locking portion 31. In this way, in the electrochemical element 1 of each embodiment, there is no particular limitation on the direction in which the front end portion 311 is folded back, and it can also be folded back radially outward of the concave container 11 as described above.

[0083] (Variant 3)

[0084] Modification 3 is Fig.11 The modification of the concave container 11 of the modification 2 shown in FIG. Fig.12 As shown, the insertion hole 115 formed in the upper end surface of the concave container 11 can also be connected to the internal space of the concave container 11. That is, the insertion hole 115 is a cutout cut in the upper end surface and the inner peripheral surface of the concave container 11. The insertion hole 115 has an opening in the upper end surface and the inner peripheral surface of the concave container 11. The insertion hole 115 only needs to have an opening in at least the upper end surface of the concave container 11 in such a way that the front end portion 311 of the elastic locking portion 31 can be inserted from above the concave container 11. Fig.10 The front end portion 311 of the elastic locking portion 31 is similar in shape to the elastic locking portion 31 shown in the figure. In this way, even if the front end portion 311 of the elastic locking portion 31 is inserted into the insertion hole 115 connected to the internal space of the concave container 11, the conductive plate 30 can be installed and fixed to the concave container 11.

[0085] (Variant 4)

[0086] like Fig.13As shown, in the electrochemical element 1 of each embodiment, the elastic locking portion 31 of the conductive plate 30 may also have a corrugated plate shape. The corrugated plate-shaped elastic locking portion 31 has a plurality of curved surfaces. When the elastic locking portion 31 is inserted into the insertion hole 115, each curved surface of the elastic locking portion 31 is pressed by the side of the insertion hole 115 and deflected in a manner extending along the insertion direction. Thus, the curved surface of the elastic locking portion 31 presses the side of the insertion hole 115 radially inward or radially outward by its elastic force. As a result, the conductive plate 30 can be easily fixed to the concave container 11.

[0087] (Variant 5)

[0088] Although not particularly shown, the insertion hole 115 may be a cutout formed on the upper end surface of the side wall portion 112. That is, the insertion hole 115 may be formed to be expanded by being pressed by the elastic locking portion 31 inserted into the cutout, and to have an opening at least on the upper end surface of the side wall portion 112. In this way, the insertion hole 115 may be a cutout if the elastic locking portion 31 of the conductive plate 30 can be inserted from above the side wall portion 112 of the concave container 11, or may be connected to the internal space of the concave container 11 as described above.

[0089] (Variant 6)

[0090] like Fig.14 As shown, in the electrochemical element 1 of each embodiment, the insertion hole 115 of the side wall portion 112 of the concave container 11 may be partially blocked by the support portion 116 so as to be able to lock the folded front end portion 311 of the elastic locking portion 31 of the conductive plate 30. The front end portion 311 of the elastic locking portion 31 inserted into the insertion hole 115 can be locked on the lower surface of each support portion 116, and even when a strong force is applied to the conductive plate 30, the elastic locking portion 31 can be prevented from escaping from the insertion hole 115. In addition, Fig.14 The concave container 11 shown is Fig.12 A modified example of the concave container 11 is shown.

[0091] (Other variations)

[0092] In each 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 positive electrode layer. In this case, the external terminal 13 functions as a negative electrode terminal and the external terminal 14 functions as a positive electrode terminal.

[0093] In the fourth embodiment described above, the flat element 50 is housed in the internal space of the housing 10 in a manner such that the outer can 51 is disposed on the bottom 111 side of the concave container 11, but the sealing can 52 may be housed in a manner such that the sealing can 52 is disposed on the bottom 111 side of the concave container 11. Figure 8 The flat element 50 is shown housed in the inner space of the housing 10 in a state in which it is turned upside down.

[0094] In the above-mentioned embodiment, the power generation element 20 is constituted by a laminated body in which the electrode layer 21, the electrode layer 22 and the solid electrolyte layer 23 are laminated, but as an isolating layer, a separator (not shown) is provided instead of the solid electrolyte layer 23, and the electrolyte and the power generation element 20 are accommodated in the internal space of the housing 10, thereby enabling the electrochemical element to be used as a lithium ion secondary battery, a lithium ion capacitor, a double electric layer capacitor, etc. In this case, the separator and the electrolyte are generally used for lithium ion secondary batteries, lithium ion capacitors or double electric layer capacitors, etc. In addition, the electrode layer 21 and the electrode layer 22 are replaced by a mixture layer of a positive electrode and a negative electrode commonly used in various electrochemical elements 1.

[0095] Furthermore, according to the present invention, it is possible to contribute to Goal 7 “Clean Energy for All” and Goal 12 “Responsible Consumption and Production” of the Sustainable Development Goals (SDGs) advocated by the United Nations.

[0096] Example

[0097] [Evaluation of vibration resistance]

[0098] Using a 0.2mm thick SUS304-CSP conductive plate, Figure 6 The electrochemical device (all-solid-state battery) shown in FIG. 1 was subjected to a vibration test as follows to evaluate the vibration resistance of the electrochemical device of this example.

[0099] The electrochemical element of the embodiment was subjected to a test of applying sinusoidal vibration in the three directions of vertical, horizontal and height. The sine wave scan was a logarithmic scan that reciprocated in the range of 7Hz to 200Hz for 15 minutes while changing the frequency, and the scan was repeated 12 times for each of the three directions. In addition, between 7Hz and 18Hz, the scan was performed with the peak acceleration maintained at 1G, and from 18Hz, the scan was performed while maintaining the full amplitude at 0.8mm until the peak acceleration reached a frequency of 8G (about 50Hz), and then the scan was performed while the peak acceleration was maintained at 1G until 200Hz.

[0100] For the electrochemical element of the embodiment subjected to the vibration test, the AC impedance at 1 kHz was measured under an applied voltage of 10 mV and compared with the value of the AC impedance measured before the vibration test, but no change was confirmed. It was confirmed that the electrical connection was well maintained by the conductive plate fixed to the side wall of the concave container.

[0101] [Evaluation of sealing performance]

[0102] Unlike the vibration resistance test, the sealing property of the outer shell of the electrochemical element of the embodiment was confirmed by the "helium leakage test method" (bombardment method) described in JIS-Z2331. The electrochemical element was placed in the container and pressurized with helium for 2 hours. After that, the surrounding of the electrochemical element was evacuated for 1 minute in the vacuum chamber. The leakage of helium was determined and confirmed. After 10 minutes, the leakage was 1×10 ﹣10 Pa·m 3 / s or less, with excellent sealing performance.

[0103] Although the embodiment has been described above, the present disclosure is not limited to the above embodiment, and the above embodiment and modified examples may be combined, and various changes may be made within a scope not departing from the gist thereof.

[0104] Explanation of symbols

[0105] 1—electrochemical element, 10—housing, 11—concave container, 12—cover material, 13—external terminal, 14—external terminal, 15—sealing ring, 111—bottom, 112—side wall, 113—conductor part, 114—conductor part, 115—insertion hole, 116—support part, 20—power generating element, 30—conductive plate, 31—elastic locking part, 311—front end part, 32—bottom surface, 33—step part, 34—spring sheet, 40—conductive sheet, 50—flat element, 51—external can, 511—plane part, 52—sealing can, 521—plane part, 53—gasket.

Claims

1. An electrochemical element, characterized in that: have: A housing having a concave container and a cover material covering an opening of the concave container, wherein the concave container has a bottom and a side wall; a power generating element sealed in the housing, comprising a first electrode layer disposed on the bottom side, a second electrode layer disposed on the cover side, and a separator disposed between the first electrode layer and the second electrode layer; and a conductive plate disposed between the power generating element and the cover material, The first electrode layer is electrically connected to a first conductive path extending from the inside to the outside of the housing. The second electrode layer is electrically connected to a second conductive path extending from the inside to the outside of the housing via the conductive plate. The concave container has an insertion hole having an opening on the upper end surface of the side wall portion. The conductive plate has an elastic locking portion extending from an edge of the conductive plate and inserted into the insertion hole and used to mount the conductive plate on the concave container. The elastic locking portion inserted into the insertion hole presses a side surface of the insertion hole.

2. The electrochemical element according to claim 1, characterized in that The elastic locking portion has a front end portion folded back in a direction opposite to an insertion direction into the insertion hole.

3. The electrochemical element according to claim 1, characterized in that The elastic locking portion has a corrugated plate shape.

4. The electrochemical device according to any one of claims 1 to 3, characterized in that A gap is formed between the conductive plate and the cover member.

5. An electrochemical element, characterized in that: have: A housing having a concave container and a cover material covering an opening of the concave container, wherein the concave container has a bottom and a side wall; A flat element having an outer packaging material and a power generation element, wherein the outer packaging material is sealed in the outer casing and includes a first electrode terminal arranged on the bottom side and a second electrode terminal arranged on the cover side, and the power generation element is sealed inside the outer packaging material and includes a first electrode layer, a second electrode layer, and a separator arranged between the first electrode layer and the second electrode layer; as well as A conductive plate disposed between the flat element and the cover material, The first electrode terminal is electrically connected to a first conductive path extending from the inside to the outside of the housing. The second electrode terminal is electrically connected to a second conductive path extending from the inside to the outside of the housing via the conductive plate. The concave container has an insertion hole having an opening on the upper end surface of the side wall portion. The conductive plate has an elastic locking portion extending from an edge of the conductive plate and inserted into the insertion hole and used to mount the conductive plate on the concave container. The elastic locking portion inserted into the insertion hole presses a side surface of the insertion hole.

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