JP2015032513A - Power storage element and method of manufacturing power storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element in which degradation in the weld quality can be suppressed, in the welding of a container body and a lid.SOLUTION: A power storage element 10 including a container 100 having a container body 111 provided with an opening and housing an electrode body 140, and a lid 110 for closing the opening is further provided with a weld zone 112 formed by welding the container body 111 and the lid 110 and having a wall surface, and a wall formed at least in the container body 111 and the lid 110 so as to form a space together with the wall surface of the weld zone 112.

Description

  The present invention relates to an electricity storage element including a container body having a container body in which an electrode body is accommodated and a lid that closes an opening of the container body, and a method for manufacturing the electricity storage element.

  The shift from gasoline cars to electric cars has become important as a global environmental problem. For this reason, development of an electric vehicle using a power storage element such as a lithium ion secondary battery as a power source is being promoted.

  Such an electric storage element has a container main body that accommodates an electrode body and the like, and a lid that closes an opening of the container main body. And an electrical storage element is manufactured by accommodating an electrode body etc. inside the said container main body, and welding the said container main body and a cover body (for example, refer patent document 1).

JP 2008-159536 A

  However, the conventional power storage element has a problem that the welding quality may be deteriorated in welding the container body and the lid.

  That is, in the conventional electricity storage element, when the container main body and the lid are welded, porosity is likely to occur at the tip of the welded portion due to the gas generated during welding. For this reason, the said porosity becomes a welding defect and welding quality may fall.

  The present invention has been made to solve the above-described problem, and provides a power storage element and a method for manufacturing the power storage element that can suppress a decrease in welding quality in welding the container body and the lid. Objective.

  In order to achieve the above object, a power storage element according to one embodiment of the present invention is a power storage element including a container having a container body in which an opening is formed and an electrode body is accommodated, and a lid that closes the opening. The container body and the lid body are welded to each other to form a space between the welded part having a wall surface and the wall surface of the welded part. And a formed wall portion.

  According to this, in the electric storage element, a space is formed by the wall surface of the welded portion formed by welding the container main body and the lid body and at least one wall portion of the container main body and the lid body. That is, since the wall surface of the welded portion is in contact with the space, when welding the container main body and the lid body, the welding gas that causes the generation of porosity escapes from the wall surface into the space. For this reason, generation | occurrence | production of a porosity is suppressed in welding of a container main body and a cover body, and the fall of welding quality can be suppressed.

  The wall portion is formed on the container body, and is formed on the lid body with a body wall portion that forms a space with a body side wall surface that is a wall surface on the container body side of the weld portion, and the weld portion. You may decide to have the cover body wall part which forms space with the cover body side wall surface which is the said wall surface of the said cover body.

  According to this, in the said electrical storage element, the space is formed by the wall part of a container main body, and the wall part of a cover body. Here, when a space is formed in one wall portion of the container main body or the lid, the shape of the welded portion becomes distorted, and there is a risk that porosity will occur due to welding on the side where the space is not formed. is there. For this reason, by forming a space in the wall part of both the container main body and the lid, the shape of the welded part does not become distorted, the generation of porosity is suppressed, and the deterioration of the welding quality can be suppressed.

  Further, the space formed by the main body side wall surface and the main body wall portion and the space formed by the lid body side wall surface and the lid body wall portion may be connected to each other. .

  According to this, in the electric storage element, since the two spaces formed by the wall surface of the welded portion and the main body wall portion and the lid body wall portion are connected to each other, the shape of the welded portion is not distorted, The generation of porosity can be suppressed, and deterioration of welding quality can be suppressed.

  The space may be formed such that a length in a direction intersecting a welding direction at the time of welding is longer than a length in the welding direction.

  According to this, in the electric storage element, since the space that is longer in the direction intersecting the welding direction is formed, it is possible to suppress the advance of the welded portion to the portion where the space is not formed. it can. For this reason, since the front-end | tip of the welding part which a porosity tends to generate | occur | produce contacts space, generation | occurrence | production of a porosity is suppressed and the fall of welding quality can be suppressed.

  The space may be arranged to be separated from an internal space in which the electrode body formed inside the container body is accommodated.

  According to this, in the power storage element, the space in contact with the welded portion is arranged away from the internal space of the container main body. Therefore, when welding is performed by laser irradiation, the space in the internal space of the container main body is used. The laser beam can be prevented from entering.

  Further, the wall surface of the welded portion is a first wall surface whose distance from the outer wall of at least one of the container body and the lid body is a first distance, and a second distance where the distance is smaller than the first distance. You may decide to have two wall surfaces.

  According to this, in the electric storage element, the portion having the second wall surface of the container is arranged closer to the outer wall than the portion having the first wall surface. The welding depth is reduced by reducing the penetration depth. Thereby, since the part which has a 2nd wall surface can be functioned as a safety valve, a safety valve can be installed easily.

  In order to achieve the above object, a method for manufacturing a power storage device according to one embodiment of the present invention includes a container having a container body in which an opening is formed and an electrode body is accommodated, and a lid that closes the opening. A method of manufacturing a storage element comprising: a recess forming step of forming a recess at a position where at least one of the container body and the lid is welded; and the container body and the lid to the wall surface of the recess Welding process for welding.

  According to this, in the method for manufacturing the electricity storage element, a recess is formed in at least one of the container body and the lid, and the container body and the lid are welded to the wall surface of the recess. In other words, since the welded portion is in contact with the wall surface of the recess, when welding the container body and the lid, gas during welding that causes the generation of porosity escapes into the recess. For this reason, generation | occurrence | production of a porosity is suppressed in welding of a container main body and a cover body, and the fall of welding quality can be suppressed.

  Moreover, in the said recessed part formation process, while forming the main body recessed part which is a recessed part in the position where the said container main body is welded, the lid body recessed part which is a recessed part is formed in the position where the said cover body is welded, and the said welding In the step, welding may be performed up to the wall surfaces of the main body recess and the lid recess.

  According to this, in the method for manufacturing the electricity storage device, the recesses are formed in both the container body and the lid, and the wall surfaces of both the recesses are welded. Here, when the concave portion is formed only on one of the container main body and the lid body, the shape of the welded portion becomes distorted, and there is a possibility that porosity is generated by welding on the side where the concave portion is not formed. For this reason, by forming a recessed part in both a container main body and a cover body, the shape of a welding part does not become distorted, generation | occurrence | production of a porosity is suppressed and the fall of welding quality can be suppressed.

  According to the electricity storage device of the present invention, it is possible to suppress a decrease in welding quality in welding the container body and the lid.

It is a perspective view which shows typically the external appearance of the electrical storage element which concerns on embodiment of this invention. It is a perspective view which shows each component with which the electrical storage element which concerns on embodiment of this invention is provided. It is sectional drawing which shows the structure of the welding location of the cover body and container main body which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the welding location of the cover body and container main body which concerns on embodiment of this invention. It is a top view which shows the structure of the cover body which concerns on embodiment of this invention. It is a top view which shows the structure of the container main body which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the recessed part formation process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the recessed part formation process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the cover body arrangement | positioning process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the cover body arrangement | positioning process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is a figure for demonstrating the welding process in the manufacturing method of the electrical storage element which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the welding location of the cover body and container main body which concern on the modification 1 of embodiment of this invention. It is sectional drawing which shows the structure of the welding location of the cover body and container main body which concern on the modification 1 of embodiment of this invention. It is sectional drawing which shows the structure of the welding location of the cover body and container main body which concern on the modification 2 of embodiment of this invention. It is sectional drawing which shows the structure of the welding location of the cover body and container main body which concern on the modification 3 of embodiment of this invention.

  Hereinafter, a power storage device and a method for manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept are described as optional constituent elements.

(Embodiment)
First, the configuration of the power storage element 10 will be described.

  FIG. 1 is a perspective view schematically showing an external appearance of a power storage device 10 according to an embodiment of the present invention. FIG. 2 is a perspective view showing each component included in power storage device 10 according to the embodiment of the present invention.

  The power storage element 10 is a secondary battery that can charge electricity and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. In addition, the electrical storage element 10 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it.

  As shown in FIG. 1, the electricity storage device 10 includes a container 100, a positive electrode terminal 200, and a negative electrode terminal 300. As shown in FIG. 2, a positive electrode current collector 120, a negative electrode current collector 130, and an electrode body 140 are accommodated inside the container 100. Note that a liquid such as an electrolytic solution is sealed inside the container 100 of the power storage element 10, but the liquid is not shown.

  The container 100 includes a container main body 111 having a rectangular cylindrical shape with an opening having a bottom, and a lid 110 that is a plate-like member that closes the opening of the container main body 111. In addition, the container 100 can seal the inside by accommodating the electrode body 140 and the like and then welding the lid body 110 and the container body 111.

  The material of the lid 110 and the container main body 111 may be any material as long as it is a weldable metal such as stainless steel. The lid 110 and the container body 111 may have any shape as long as the lid 110 and the container body 111 are welded and sealed. In addition, as the electrolytic solution (nonaqueous electrolytic solution) sealed in the container 100, there is no particular limitation on the type thereof as long as the performance of the power storage element 10 is not impaired, and various types can be selected.

  The electrode body 140 includes a positive electrode, a negative electrode, and a separator, and is a member that can store electricity. The positive electrode is obtained by forming a positive electrode active material layer on a long belt-like positive electrode base foil made of aluminum or an aluminum alloy. The negative electrode is obtained by forming a negative electrode active material layer on a long strip-shaped negative electrode base foil made of copper, a copper alloy, or the like. The separator is a microporous sheet made of resin.

  Here, the positive electrode active material used for the positive electrode active material layer or the negative electrode active material used for the negative electrode active material layer may be a known material as long as it is a positive electrode active material or a negative electrode active material capable of occluding and releasing lithium ions. Can be used.

  And the electrode body 140 is formed by winding what is arranged in layers so that the separator is sandwiched between the negative electrode and the positive electrode. In addition, in the same figure, although the ellipse shape was shown as a shape of the electrode body 140, circular shape or elliptical shape may be sufficient. The shape of the electrode body 140 is not limited to a wound type, and may be a shape in which flat plate plates are laminated.

  The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode of the electrode body 140, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode of the electrode body 140. In other words, the positive electrode terminal 200 and the negative electrode terminal 300 lead the electricity stored in the electrode body 140 to the external space of the power storage element 10, and in order to store the electricity in the electrode body 140, It is an electrode terminal made of metal for introducing. The positive electrode terminal 200 and the negative electrode terminal 300 are attached to the lid body 110 disposed above the electrode body 140.

  The positive electrode current collector 120 is disposed between the positive electrode of the electrode body 140 and the side wall of the container main body 111 of the container 100, and has electrical conductivity and rigidity electrically connected to the positive electrode terminal 200 and the positive electrode of the electrode body 140. It is a member provided with. The positive electrode current collector 120 is made of aluminum or an aluminum alloy, like the positive electrode base material foil of the electrode body 140.

  The negative electrode current collector 130 is disposed between the negative electrode of the electrode body 140 and the side wall of the container body 111 of the container 100, and has electrical conductivity and rigidity that are electrically connected to the negative electrode terminal 300 and the negative electrode of the electrode body 140. It is a member provided with. The negative electrode current collector 130 is formed of copper or a copper alloy, like the negative electrode base foil of the electrode body 140.

  Next, the structure of the welding location between the lid 110 and the container body 111 will be described in detail.

  3A and 3B are cross-sectional views showing the configuration of the welded portion between lid 110 and container body 111 according to the embodiment of the present invention. Specifically, FIG. 3A is an enlarged cross-sectional view showing an enlarged cross section at A part shown in FIG. 1, and FIG. 3B is an enlarged cross-sectional view showing an enlarged cross section at B part shown in FIG. It is.

  FIG. 4 is a plan view showing the configuration of the lid 110 according to the embodiment of the present invention. Specifically, this figure is a plan view showing the configuration of the lid 110 when the lid 110 before being welded to the container body 111 is viewed from below (Z-axis minus direction). In addition, the A1-A1 cross section in the same figure respond | corresponds to the cross section of the cover body 110 shown to FIG. 3A, and the B1-B1 cross section respond | corresponds to the cross section of the cover body 110 shown in FIG. 3B.

  FIG. 5 is a plan view showing the configuration of the container body 111 according to the embodiment of the present invention. Specifically, this figure is a plan view showing the configuration of the container body 111 when the container body 111 before being welded to the lid 110 is viewed from above (Z-axis plus direction). In addition, the A2-A2 cross section in the figure corresponds to the cross section of the container main body 111 shown in FIG. 3A, and the B2-B2 cross section corresponds to the cross section of the container main body 111 shown in FIG. 3B.

  First, the configuration of the lid 110 will be described.

  As shown in FIGS. 3A, 3B and 4, the lid body 110 has a positioning portion 113 for positioning with the container body 111, and lid body concave portions 110 a and 114 a are disposed outside the positioning portion 113. Is formed.

  The positioning portion 113 is an annular protrusion that is formed along the outer periphery of the lid 110 and protrudes downward (Z-axis minus direction). Specifically, the positioning unit 113 has a rectangular cross section, and is formed in a rectangular ring shape along the rectangular outer periphery of the lid 110. And the positioning part 113 is arrange | positioned inside the opening part of the container main body 111, the lid body 110 is positioned on the container main body 111, and the lid body 110 and the container main body 111 are welded.

  The lid recesses 110a and 114a are recesses formed at positions where the lid 110 is welded. Specifically, the lid recesses 110a and 114a are formed so as to surround the positioning portion 113 on the outer side of the positioning portion 113 along the outer periphery of the lid 110 and are recessed upward (Z-axis plus direction). It is a recessed part. More specifically, the lid recesses 110a and 114a are recesses having a rectangular cross section, and are formed in a rectangular ring shape along the rectangular outer periphery of the lid 110.

  Here, the lid recess 114a is a recess formed on the short side (the X axis direction plus side) of the lid 110, and the lid recess 110a has three sides other than the side where the lid recess 114a is formed. It is a recessed part formed in the side (X-axis direction minus side, Y-axis direction plus and minus side). The lid recess 114a is disposed at a position where the distance from the outer wall of the lid 110 is smaller than that of the lid recess 110a.

  Further, when the lid 110 and the container main body 111 are welded, they are welded to the wall surfaces of the lid concave portions 110a and 114a. That is, the wall surface of the lid concave portion 110a forms a wall surface (lid body side wall surface 112a) of the welded portion 112 described later, and the wall surface of the lid concave portion 114a is a wall surface of the welded portion 116 described later (lid body side wall surface 116a). Is forming.

  The lid recess 110a is a position facing the lid side wall surface 112a of the welded portion 112, and is located on the inner side (the side far from the outer wall of the lid 110) than the lid side wall surface 112a. have. A lid-side space 110b is formed inward of the lid recess 110a surrounded by the lid side wall surface 112a and the lid wall 110c. That is, the lid wall portion 110c is formed in the lid body 110 so as to form a space with the lid side wall surface 112a that is the wall surface of the welded portion 112 (so as to form a space between the lid side wall surface 112a). It is the planar wall part made.

  Similarly, the lid concave portion 114a is located at a position facing the lid side wall surface 116a of the welded portion 116 and on the inner side of the lid side wall surface 116a (the side far from the outer wall of the lid 110). A wall 114c is provided. A lid-side space 114b is formed inward of the lid recess 114a surrounded by the lid side wall surface 116a and the lid wall portion 114c. That is, the lid wall portion 114c forms a space with the lid side wall surface 116a that is the wall surface on the lid 110 side of the welded portion 116 (so as to form a space between the lid side wall surface 116a). It is a planar wall portion formed on the lid body 110.

  The lid-side spaces 110b and 114b are spaces formed by increasing the depth (depth in the Z-axis direction) of the lid recesses 110a and 114a. That is, the lid-side spaces 110b and 114b are formed such that the length in the direction (Z-axis direction) intersecting the welding direction (Y-axis direction or X-axis direction) during welding is longer than the length in the welding direction. ing.

  Further, the lid-side spaces 110b and 114b are arranged away from the internal space 111k in which the electrode body 140 formed inside the container body 111 is accommodated. That is, the lid-side spaces 110b and 114b are formed without being spatially connected to the internal space 111k.

  Next, the configuration of the container body 111 will be described.

  As shown in FIGS. 3A, 3B and 5, the container body 111 is formed with body recesses 111a and 115a. Specifically, main body recesses 111a and 115a are formed at positions corresponding to the lid recesses 110a and 114a.

  The main body concave portions 111a and 115a are concave portions formed at positions where the container main body 111 is welded. Specifically, the main body recesses 111a and 115a are annular recesses formed along the outer periphery of the container body 111 and recessed downward (Z-axis minus direction). More specifically, the main body concave portions 111 a and 115 a are concave portions having a rectangular cross section, and are formed in a rectangular ring shape along the outer periphery of the rectangular shape of the container main body 111.

  Here, the main body recess 115a is a recess formed on the short side (X-axis direction plus side) of the container main body 111 corresponding to the lid recess 114a, and the main body recess 111a corresponds to the lid recess 110a. Thus, the recesses are formed on three sides (X-axis direction minus side, Y-axis direction plus and minus sides) other than the side where the main body recess 115a is formed. Moreover, the main body recessed part 115a is arrange | positioned in the position where the distance from the outer wall of the container main body 111 is smaller than the main body recessed part 111a.

  Further, when the lid 110 and the container main body 111 are welded, the wall surfaces of the main body recesses 111a and 115a are also welded. That is, the wall surface of the main body recess 111a forms a wall surface (main body side wall surface 112b) of a welded portion 112 described later, and the wall surface of the main body concave portion 115a forms a wall surface of the welded portion 116 (main body side wall surface 116b) described later. doing.

  The main body recess 111a has a main body wall portion 111c at a position facing the main body side wall surface 112b of the welded portion 112 and on the inner side (the side far from the outer wall of the container main body 111) than the main body side wall surface 112b. doing. A main body side space 111b is formed inside the main body concave portion 111a surrounded by the main body side wall surface 112b and the main body wall portion 111c. That is, the main body wall portion 111c forms a space with the main body side wall surface 112b which is the wall surface on the container main body 111 side of the welded portion 112 (so as to form a space between the main body side wall surface 112b) and the container. It is a planar wall portion formed in the main body 111.

  Similarly, the main body concave portion 115a is located at a position facing the main body side wall surface 116b of the welded portion 116 and on the inner side (the side farther from the outer wall of the container main body 111) than the main body side wall surface 116b. 115c. A main body side space 115b is formed inside the main body concave portion 115a surrounded by the main body side wall surface 116b and the main body wall portion 115c. That is, the main body wall portion 115c is formed in the container main body 111 so as to form a space with the main body side wall surface 116b which is the wall surface of the welded portion 116 (so as to form a space between the main body side wall surface 116b). A flat wall portion.

  The main body side spaces 111b and 115b are spaces formed by increasing the depths (depths in the Z-axis direction) of the main body concave portions 111a and 115a. That is, the main body side spaces 111b and 115b are formed such that the length in the direction (Z-axis direction) intersecting the welding direction (Y-axis direction or X-axis direction) during welding is longer than the length in the welding direction. ing.

  The main body side spaces 111b and 115b are arranged apart from the internal space 111k in which the electrode body 140 formed inside the container main body 111 is accommodated. That is, the main body side spaces 111b and 115b are formed without being spatially connected to the internal space 111k.

  Further, the main body side space 111b that is a space formed by the main body side wall surface 112b and the main body wall portion 111c, and the lid body side space 110b that is a space formed by the lid side wall surface 112a and the lid body wall portion 110c are: Connected and formed.

  That is, the lid side wall surface 112a and the main body side wall surface 112b are connected to form the same plane, and the lid body wall portion 110c and the main body wall portion 111c are connected to form the same plane. Thereby, the main body side space 111b and the lid side space 110b are connected to form one space.

  Similarly, a main body side space 115b that is a space formed by the main body side wall surface 116b and the main body wall portion 115c, and a lid side space 114b that is a space formed by the lid side wall surface 116a and the lid body wall portion 114c. Are connected and formed.

  That is, the lid side wall surface 116a and the main body side wall surface 116b are connected to form the same plane, and the lid body wall portion 114c and the main body wall portion 115c are connected to form the same plane. Thereby, the main body side space 115b and the lid body side space 114b are connected to form one space.

  Next, the structure of the welding parts 112 and 116 is demonstrated.

  As shown in FIGS. 3A and 3B, the welded portions 112 and 116 are welded portions formed by welding the container main body 111 and the lid 110. That is, the welded portions 112 and 116 are welded portions formed by melting the container main body 111 and the lid body 110, and are formed across the container main body 111 and the lid body 110.

  And the welding part 112 has the wall surface which consists of the cover body side wall surface 112a and the main body side wall surface 112b. That is, the lid side wall surface 112a is a wall surface of the welded portion 112 on the lid body 110 side, and is a planar wall surface outside the lid body concave portion 110a (side closer to the outer wall of the lid body 110). The main body side wall surface 112b is a wall surface on the container main body 111 side of the welded portion 112, and is a flat wall surface outside the main body concave portion 111a (side closer to the outer wall of the container main body 111).

  Similarly, the welded portion 116 has a wall surface composed of a lid side wall surface 116a and a main body side wall surface 116b. That is, the lid side wall surface 116a is a wall surface on the lid body 110 side of the welded portion 116, and is a planar wall surface outside the lid body recess 114a (side closer to the outer wall of the lid body 110). The main body side wall surface 116b is a wall surface on the container main body 111 side of the welded portion 116, and is a flat wall surface outside the main body concave portion 115a (side closer to the outer wall of the container main body 111).

  Here, the lid side wall surface 112a and the main body side wall surface 112b are first wall surfaces whose distance from the outer wall of at least one of the container main body 111 and the lid body 110 is the first distance R1. The lid side wall surface 116a and the main body side wall surface 116b are second wall surfaces whose second distance R2 is smaller than the first distance R1 from the outer wall of at least one of the container main body 111 and the lid body 110.

  That is, the lid recess 114a is formed closer to the outer wall of the lid 110 than the lid recess 110a, and the main body recess 115a is formed closer to the outer wall of the container body 111 than the main body recess 111a. Therefore, the lid side wall surface 116a and the main body side wall surface 116b, which are the second wall surfaces, are arranged closer to the outer walls of the lid body 110 and the container main body 111 than the lid side wall surface 112a and the main body side wall surface 112b, which are the first wall surfaces. Has been.

  Next, the manufacturing method of the electrical storage element 10 is demonstrated.

  FIG. 6 is a flowchart showing a method for manufacturing power storage device 10 according to the embodiment of the present invention. Specifically, this figure is a flowchart for explaining a process of welding the container main body 111 and the lid body 110 in order to manufacture the electricity storage element 10.

  As shown in the figure, first, as a recess forming step, a recess is formed at a position where at least one of the container main body 111 and the lid 110 is welded (S102). In the present embodiment, a recess is formed at a position where both the container main body 111 and the lid 110 are welded. This recess forming step will be described in detail below.

  7 and 8 are diagrams for explaining a recess forming step in the method for manufacturing power storage device 10 according to the embodiment of the present invention.

  First, as shown in FIG. 7, lid recesses 110a and 114a, which are recesses, are formed at positions where the lid 110 is welded. Specifically, the distance between the lid wall portion 110d that is the wall portion outside the lid recess 110a (the side closer to the outer wall of the lid body 110) and the outer wall of the lid body 110 is the first distance R1. A lid recess 110a is formed. Further, the distance between the lid wall portion 114d which is the wall portion outside the lid concave portion 114a (the side closer to the outer wall of the lid body 110) and the outer wall of the lid body 110 is set to a second distance R2 which is smaller than the first distance R1. The lid recess 114a is formed so as to be.

  In other words, the lid recess 114a is formed on the short side (X axis direction plus side) of the lid 110, and the three sides other than the side where the lid recess 114a is formed (X axis direction minus side, Y axis direction plus). And a concave portion 110a on the negative side.

  The position where the lid recess 114 a is formed is not limited to the short side of the lid 110, and the lid recess 114 a may be formed on the long side of the lid 110. Further, the lid recess 114a may be formed on a part of the short side or the long side of the lid 110, or may be formed on the short side or the long side. It may be.

  Moreover, as shown in FIG. 8, main body concave portions 111a and 115a, which are concave portions, are formed at positions where the container main body 111 is welded. Specifically, the main body concave portion is set such that the distance between the main body wall portion 111d which is the wall portion outside the main body concave portion 111a (the side closer to the outer wall of the container main body 111) and the outer wall of the container main body 111 is the first distance R1. 111a is formed. Further, the distance between the main body wall 115d, which is the wall on the outer side of the main body recess 115a (the side closer to the outer wall of the container main body 111), and the outer wall of the container main body 111 is the second distance R2 that is smaller than the first distance R1. Next, the main body recess 115a is formed.

  In other words, the body recess 115a is formed on the short side (X-axis direction plus side) of the container body 111 in correspondence with the lid recess 114a, and the body recess 115a is formed in correspondence with the lid recess 110a. Main body recesses 111a are formed on the other three sides (X-axis direction minus side, Y-axis direction plus and minus sides).

  The position at which the main body recess 115a is formed is not limited to the short side of the container body 111, and the main body recess 115a may be formed on the long side of the container body 111. The main body recess 115a may be formed on a part of the short side or the long side of the container main body 111, or a plurality of main body recesses 115a may be formed on the short side or the long side. May be.

  Returning to FIG. 6, next, as a lid body placement step, the lid body 110 is placed on the container body 111 (S <b> 104). FIG. 9A and FIG. 9B are diagrams for explaining a lid arrangement step in the method for manufacturing power storage device 10 according to the embodiment of the present invention.

  As shown in FIGS. 9A and 9B, the lid 110 is positioned on the container body 111 by the positioning portion 113 of the lid 110. Specifically, the lid 110 is positioned on the container body 111 such that the lid recess 110a is disposed on the body recess 111a and the lid recess 114a is disposed on the body recess 115a.

  Thereby, the lid body wall part 110d and the main body wall part 111d form a single plane, and the lid body wall part 114d and the main body wall part 115d form a single plane. In addition, the lid-side space 110b in the lid recess 110a and the body-side space 111b in the body recess 111a form a space, and the lid-side space 114b in the lid recess 114a and the body-side space 115b in the body recess 115a. And form a space.

  Returning to FIG. 6, next, as a welding process, the container main body 111 and the lid 110 are welded to the wall surface of the recess (S106). FIG. 10 is a diagram for describing a welding process in the method for manufacturing power storage device 10 according to the embodiment of the present invention.

  First, as shown in FIG. 10 (a), the laser beam L1 is irradiated toward the place where the container main body 111 and the lid 110 are welded, so that the wall surfaces of the main body recess 111a and the lid recess 110a. The container main body 111 and the lid 110 are welded to the main body wall 111d and the lid wall 110d. Similarly, the container main body 111 and the lid 110 are welded to the main body wall 115d and the lid wall 114d, which are the wall surfaces of the main body recess 115a and the lid recess 114a.

  In the present embodiment, the horizontal surfaces of the container main body 111 and the lid body 110 overlap each other in the vertical direction (Z-axis direction), so that the overlapping portion between the horizontal surfaces becomes a welding location. For this reason, the container main body 111 and the lid body 110 can be welded by irradiating the laser beam L1 in the horizontal direction (the Y-axis direction in the figure) toward the welding location.

  Thereby, as shown in FIG. 10B, a welded portion 112 having a lid side wall surface 112a and a main body side wall surface 112b is formed. Similarly, a welded portion 116 having a lid side wall surface 116a and a main body side wall surface 116b is formed.

  As described above, according to power storage device 10 according to the embodiment of the present invention, the wall surfaces of welded portions 112 and 116 formed by welding container body 111 and lid body 110, container body 111 and lid body. A space is formed by at least one wall portion of 110. That is, since the wall surfaces of the welded portions 112 and 116 are in contact with the space, when welding the container main body 111 and the lid body 110, gas during welding that causes the generation of porosity is transferred from the wall surface to the space. Go through. For this reason, generation | occurrence | production of a porosity is suppressed in welding with the container main body 111 and the cover body 110, and the fall of welding quality can be suppressed.

  Further, conventionally, it has been necessary to manage the welding depth uniformly in order to ensure uniform welding strength. However, according to the storage element 10, since welding is performed through the space, the welding depth can be easily obtained. The thickness can be made uniform. Moreover, according to the electrical storage element 10, since welding depth can be adjusted by adjusting the position of space, welding strength can be adjusted easily.

  Further, in the electricity storage element 10, a space is formed by the wall portion of the container body 111 and the wall portion of the lid 110. Here, when the space is formed by one wall portion of the container main body 111 or the lid body 110, the shape of the welded portions 112 and 116 becomes irregular, and the porosity of the welded portion on the side where the space is not formed is reduced. Occurrence may occur. For this reason, by forming a space in the wall portions of both the container main body 111 and the lid body 110, the shapes of the welded portions 112 and 116 are not distorted, the generation of porosity is suppressed, and the deterioration of the welding quality is suppressed. be able to.

  Further, in the electricity storage device 10, since the two spaces formed by the wall surface of the welded portions 112 and 116, the main body wall portions 111d and 115d, and the lid body wall portions 110d and 114d are connected to each other, the welded portions 112, The shape of 116 does not become distorted, generation of porosity is suppressed, and deterioration in welding quality can be suppressed.

  Moreover, in the electrical storage element 10, since the space which is longer in the direction intersecting the welding direction is formed, it is possible to suppress the leading ends of the welded portions 112 and 116 from reaching the portion where the space is not formed. it can. For this reason, since the front-end | tip of the welding parts 112 and 116 which are easy to generate | occur | produce a porosity contacts space, generation | occurrence | production of a porosity is suppressed and it can suppress the deterioration of welding quality, and ensures adjustment of welding depth. Can do.

  Further, in the electric storage element 10, the space in contact with the welded portions 112 and 116 is disposed away from the internal space 111k of the container body 111. Therefore, when welding is performed by laser irradiation, the space of the container body 111 is reduced. The laser beam can be prevented from entering the internal space 111k.

  Moreover, in the electrical storage element 10, the part which has the 2nd wall surface (the cover body side wall surface 116a and the main body side wall surface 116b) of the container 100 is more space than the part which has the 1st wall surface (the cover body side wall surface 112a and the main body side wall surface 112b). Is placed near the outer wall. Thereby, since the penetration depth in the part having the second wall surface can be reduced to reduce the welding strength, and the part having the second wall surface can function as a safety valve, the safety valve can be easily installed. .

  In addition, according to the method for manufacturing power storage device 10 according to the embodiment of the present invention, a recess is formed in at least one of container body 111 and lid 110, and container body 111 and lid 110 are connected to the wall surface of the recess. Weld until. That is, because the welded portions 112 and 116 are in contact with the wall surface of the recess, when welding the container body 111 and the lid 110, the gas during welding that causes the generation of porosity escapes into the recess. . For this reason, generation | occurrence | production of a porosity is suppressed in welding with the container main body 111 and the cover body 110, and the fall of welding quality can be suppressed.

  Moreover, in the manufacturing method of the electrical storage element 10, a recessed part is formed in both the container main body 111 and the cover body 110, and it welds to the wall surface of both recessed parts. Here, when the concave portion is formed only on one of the container body 111 and the lid body 110, the shape of the welded portions 112 and 116 becomes distorted, and porosity is generated by welding on the side where the concave portion is not formed. May occur. For this reason, by forming recesses in both the container main body 111 and the lid body 110, the shapes of the welded portions 112 and 116 are not distorted, the generation of porosity is suppressed, and the deterioration of welding quality can be suppressed. .

  The power storage element 10 and the manufacturing method thereof according to the embodiment of the present invention have been described above, but the present invention is not limited to the above embodiment. That is, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  For example, in the above embodiment, the recess formed in the lid 110 and the container body 111 is a recess having a rectangular cross section, but the cross section is not limited to a rectangular shape. For example, the recesses formed in the lid 110 and the container body 111 may be polygonal recesses (the lid recess 110e and the body recess 111e) having a cross section other than a rectangular shape, as shown in FIG. 11A. As shown in FIG. 11B, recesses (cover recess 110f and body recess 111f) having a curved cross section may be used. FIG. 11A and FIG. 11B are cross-sectional views showing a configuration of a welded portion between lid 110 and container body 111 according to Modification 1 of the embodiment of the present invention. Also by this, the same effect as the above-mentioned embodiment can be produced.

  Moreover, in the said embodiment, the recessed part is formed in both the cover body 110 and the container main body 111, and a wall is formed in both the cover body 110 and the container main body 111 so that space may be formed with the wall surface of the welding part 112. The part was decided to be formed. However, the concave portion is formed only in one of the lid 110 and the container main body 111, and the wall portion that forms a space with the wall surface of the welded portion 112 is provided in either the lid 110 or the container main body 111. However, it may be formed only.

  In the above-described embodiment, the lid-side spaces 110b and 114b and the main body-side spaces 111b and 115b are arranged at corresponding positions and connected to form a space. However, the lid body side spaces 110b and 114b and the main body side spaces 111b and 115b may be disposed at slightly shifted positions, or may be independent spaces.

  Moreover, in the said embodiment, the lid body side space 110b, 114b and the main body side space 111b, 115b are formed so that the length in the direction crossing the welding direction is longer than the length in the welding direction. It was. However, the shapes of the lid side spaces 110b and 114b and the main body side spaces 111b and 115b are not limited, and the length in the direction intersecting the welding direction is formed to be shorter than the length in the welding direction. May be.

  In the above embodiment, the lid-side spaces 110b and 114b and the main body-side spaces 111b and 115b are arranged to be separated from the internal space 111k, but are connected to the internal space 111k. It does not matter even if the configuration is.

  Moreover, in the said embodiment, the wall surface of the welding part 116 was arrange | positioned in the position closer to an outer wall than the wall surface of the welding part 112, and decided to have a function of a safety valve. However, a safety valve may be provided separately, and the wall surface of the welded portion 116 and the wall surface of the welded portion 112 may be disposed at the same position from the outer wall.

  Moreover, in the said embodiment, the container main body 111, the cover body 110, and the container main body 111 and the cover body 110 are irradiated by irradiating the laser beam L1 to a horizontal direction (Y-axis direction) toward the overlapping part of the horizontal surfaces of the container main body 111 and the cover body 110. We decided to weld. However, the container body and the lid body may be welded by irradiating the laser beam in the vertical direction (Z-axis direction) toward the overlapping portion of the vertical surfaces of the container body and the lid body. This will be specifically described below.

  FIG. 12 is a cross-sectional view showing a configuration of a welded portion between the lid body and the container main body according to Modification 2 of the embodiment of the present invention. Moreover, FIG. 13 is sectional drawing which shows the structure of the welding location of the cover body and container main body which concern on the modification 3 of embodiment of this invention.

  First, as shown in FIG. 12A, the lid 150 is formed with a lid recess 150a that is recessed in the horizontal direction (Y-axis direction in the figure), and the container body 151 also has a horizontal direction. A main body recess 151a that is recessed in the Y-axis direction in the figure is formed. Then, the lid 150 is placed on the stepped recess formed in the inner peripheral portion of the container main body 151, whereby the lid 150 is positioned on the container main body 151. Specifically, the lid 150 is positioned on the container main body 151 such that the main body recess 151a and the lid recess 150a are arranged side by side in the horizontal direction.

  Accordingly, the lid body wall portion 150c and the main body wall portion 151c form a single plane, and the lid body wall portion 150d and the main body wall portion 151d form a single plane, and the lid side space 150b in the lid body concave portion 150a. And the main body side space 151b in the main body recess 151a form a space.

  And by irradiating the laser beam L2 toward the place where the container main body 151 and the lid 150 are welded, the main body wall 151d and the lid wall 150d are the wall surfaces of the main body recess 151a and the lid recess 150a. The container body 151 and the lid 150 are welded.

  In this modification, the vertical surfaces of the container main body 151 and the lid 150 overlap in the horizontal direction (Y-axis direction in the figure), and the overlapping portion of the vertical surfaces becomes a welding location. For this reason, the container main body 151 and the lid 150 can be welded by irradiating the laser beam L2 in the vertical direction (Z-axis direction) toward the welding location.

  Thereby, as shown in FIG. 12B, a welded portion 152 having a lid side wall surface 152a and a main body side wall surface 152b is formed. That is, the lid body side space 150b is formed by the lid body side wall surface 152a and the lid body wall portion 150c of the welded portion 152, and the main body side space 151b is formed by the main body side wall surface 152b and the main body wall portion 151c of the welded portion 152.

  In addition, since the structure of each part of the cover recessed part 150a and the main body recessed part 151a is the same as the structure of each part of the cover recessed part 110a and the main body recessed part 111a in the said embodiment, detailed description is abbreviate | omitted.

  Further, as shown in FIG. 13A, the lid 160 is formed with a lid recess 160a that is recessed in the horizontal direction (Y-axis direction in the figure), and the container body 161 also has a horizontal direction. A main body recess 161a that is recessed in the Y-axis direction in the figure is formed. Then, the portion projecting outward from the lid body 160 is placed on the container body 161, whereby the lid body 160 is positioned on the container body 161. Specifically, the lid body 160 is positioned on the container body 161 so that the main body recess portion 161a and the lid body recess portion 160a are arranged side by side in the horizontal direction.

  Accordingly, the lid body wall portion 160c and the main body wall portion 161c form a single plane, and the lid body wall portion 160d and the main body wall portion 161d form a single plane, and the lid side space 160b in the lid body concave portion 160a. And the main body side space 161b in the main body concave portion 161a form a space.

  And by irradiating the laser beam L3 toward the place where the container main body 161 and the lid 160 are welded, the main body concave portion 161a and the main body wall portion 161d and the lid body wall portion 160d which are the wall surfaces of the lid concave portion 160a. The container main body 161 and the lid body 160 are welded through. That is, the laser beam L3 is irradiated so as to penetrate and weld the portion protruding outward of the lid 160.

  In the present modification, as in Modification 2, the vertical surfaces of the container main body 161 and the lid body 160 overlap in the horizontal direction (Y-axis direction in the figure), so that the overlapping portions of the vertical surfaces overlap each other. Becomes the welding point. For this reason, the container main body 161 and the lid body 160 can be welded by irradiating the laser beam L3 in the vertical direction (Z-axis direction) toward the welding location.

  Thereby, as shown in FIG. 13B, a welded portion 162 having a lid side wall surface 162a and a main body side wall surface 162b is formed. That is, the lid body side space 160b is formed by the lid side wall surface 162a and the lid body wall portion 160c of the welded portion 162, and the main body side space 161b is formed by the main body side wall surface 162b and the main body wall portion 161c of the welded portion 162.

  In addition, since the structure of each part of the cover recessed part 160a and the main body recessed part 161a is the same as the structure of each part of the cover recessed part 110a and the main body recessed part 111a in the said embodiment, detailed description is abbreviate | omitted.

  As described above, the same effects as those of the above-described embodiment can also be achieved by the power storage elements according to Modifications 2 and 3 of the embodiment of the present invention. In Modifications 2 and 3, the same modification as in the above-described embodiment such as Modification 1 may be applied.

  The present invention is applicable to power storage elements such as lithium ion secondary batteries.

10 Storage element 100 Container 110, 150, 160 Lid 110a, 110e, 110f, 114a, 150a, 160a Lid recess 110b, 114b, 150b, 160b Lid side space 110c, 110d, 114c, 114d, 150c, 150d, 160c, 160d Lid wall 111, 151, 161 Container body 111a, 111e, 111f, 115a, 151a, 161a Body recess 111b, 115b, 151b, 161b Body side space 111c, 111d, 115c, 115d, 151c, 151d, 161c, 161d Main body wall portion 111k Internal space 112, 116, 152, 162 Welded portion 112a, 116a, 152a, 162a Lid side wall surface 112b, 116b, 152b, 162b Main body side wall surface 113 Positioning portion 12 Positive electrode current collector 130 negative electrode current collector 140 electrode body 200 a positive electrode terminal 300 a negative electrode terminal

Claims (8)

An electrical storage element comprising a container having a container body in which an opening is formed and an electrode body is accommodated, and a lid that closes the opening,
A welded portion having a wall surface formed by welding the container body and the lid;
An electricity storage device comprising: a wall portion formed on at least one of the container body and the lid so as to form a space with the wall surface of the welded portion. The wall is
A main body wall portion formed in the container main body and forming a space with a main body side wall surface which is a wall surface on the container main body side of the welding portion;
The power storage device according to claim 1, further comprising: a lid wall portion that is formed on the lid body and forms a space with a lid side wall surface that is a wall surface on the lid side of the welded portion. The electrical storage according to claim 2, wherein a space formed by the main body side wall surface and the main body wall portion and a space formed by the lid body side wall surface and the lid body wall portion are connected to each other. element. The storage element according to any one of claims 1 to 3, wherein the space is formed such that a length in a direction intersecting a welding direction at the time of welding is longer than a length in the welding direction. The power storage device according to claim 1, wherein the space is disposed apart from an internal space in which the electrode body formed inside the container main body is accommodated. The wall surface of the weld is
A first wall surface at which a distance from an outer wall of at least one of the container body and the lid body is a first distance;
The power storage device according to claim 1, further comprising: a second wall surface, wherein the distance is a second distance that is smaller than the first distance. An electrical storage element manufacturing method comprising a container having a container body in which an opening is formed and an electrode body is housed, and a lid that closes the opening,
A recess forming step of forming a recess at a position where at least one of the container main body and the lid is welded;
And a welding step of welding the container body and the lid to the wall surface of the recess. In the recess forming step, a body recess that is a recess is formed at a position where welding of the container body is performed, and a lid recess that is a recess is formed at a position where welding of the lid is performed,
The method for manufacturing a storage element according to claim 7, wherein in the welding step, welding is performed up to the wall surfaces of the main body recess and the lid recess.

Images