JP2013012363A - Storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage element capable of achieving a compact size and a high capacity by suppressing a displacement between a lid and a collector.SOLUTION: The storage element includes: a power generation element 101; a container 102 that stores the power generation element 101; a metal lid 103 that closes an opening section of the container 102 and has a first engagement section 131; and a collector 104 that has a second engagement section 142 engaging with the first engagement section 131 under a fitting state.

Description

  The present invention relates to a power storage element, and more particularly to a power storage element in which a current collector is attached to a lid that closes a container that houses a power generation element.

  In recent years, driving vehicles and traveling vehicles that use electric power as a part of the driving source, such as hybrid vehicles and electric vehicles, have attracted attention, and power storage devices having high energy capacity have been put to practical use as power sources for such traveling vehicles. Has been. In this specification and claims, the term “storage element” is used in a concept including both a battery (such as a lithium ion battery and a nickel metal hydride battery) and a capacitor (such as an electric double layer capacitor). Yes.

  In particular, as an electric storage element mounted in an automobile or the like that is required to pass a large current, a casing composed of a thin rectangular parallelepiped container and a lid that closes the container, and most of the internal volume of the casing There are non-aqueous electrolyte secondary batteries consisting of power generation elements. In addition, this secondary battery has an electrode terminal attached to the outer surface of the lid, and a current collector that connects the electrode terminal and the power generation element is disposed inside the casing, and power is supplied from the power generation element. It is taken out of the casing and supplies power to the power generation element.

  Furthermore, the current collector is physically fixed to the lid via an insulating member, and is electrically and physically connected to the end of the power generation element. Therefore, the power generation element is physically fixed to the lid through the current collector, and can supply and demand power in an insulated state from the housing.

  In manufacturing such a secondary battery, since it is necessary to clearly and easily determine the position of the current collector with respect to the lid, the secondary battery described in Patent Document 1 includes a lid, an insulating member, and a lid. The position of the current collector is determined via the insulator by engaging the body and aligning the positions, and further by engaging the insulating member and the current collector.

JP 2010-212240 A

  However, when the current collector is physically fixed to the lid, it may be fixed using a rivet. When the rivet is crushed and the current collector and the lid are fixed, the tool head in contact with the rivet is rotated with the pressing direction as the rotation axis, and crushed while applying rotation. In this case, the current collector and the lid generate a force to rotate in the opposite direction in the rotation direction of the tool. The insulating member cannot resist this force, and the current collector and the lid may be in a shifted state. When a deviation occurs between the current collector and the lid in this manner, the power generation element held by the current collector is distorted, and the deviation or distortion is adversely affected by being exposed to vibration for a long time. Is concerned.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an electric storage element capable of easily and firmly avoiding the displacement of the current collector with respect to the lid that occurs during assembly and suppressing the occurrence of distortion of the power generation element Is the primary purpose.

  In addition, the ratio of the power generation element to the internal volume of the housing is preferably as large as possible. However, in order to increase the structural strength of the insulating member, it is necessary to increase the insulating member, and the ratio is increased. It has become difficult. In addition, it is desirable to make the structure of the portion where the power generator and electrode terminals that do not directly contribute to power generation and power storage are as compact as possible, and to save space in the place where the power storage element is disposed. .

  This invention is made | formed in view of the said subject, and makes the provision of the electrical storage element which can improve the ratio which an electric power generation element occupies with respect to the internal volume of a housing | casing, and can be set as a compact structure as a 2nd objective. .

  In order to achieve the first object, a power storage element according to the present invention includes a power generation element, a container that houses the power generation element, a metal that closes an opening of the container and has a first engagement portion. A current collector having a second engagement portion engaged with the first engagement portion in a fitted state, and an electrode terminal disposed on the opposite side of the current collector with respect to the lid It is characterized by providing.

  Here, the engagement state means that one of the first engagement portion and the second engagement portion has a convex shape, and the other is engaged with at least a part of the convex shape being inserted. It is a bottomed hole or a through hole. Further, the first engagement portion and the second engagement portion are not limited to those directly engaged, and include cases where the first engagement portion and the second engagement portion are engaged via other members such as an insulating member.

  The first engagement portion may include a protrusion that protrudes toward the power generation element, and the second engagement portion may include a hole that engages with the protrusion in a fitted state.

  According to this, since the first engagement portion of the lid and the second engagement portion of the current collector are engaged with each other with at least a part of the first insertion portion inserted into the other, the fastening member collects the lid. Even if the current collector is about to shift when the current body is fixed, the first engagement portion and the second engagement portion are firmly engaged with each other, thereby suppressing the occurrence of displacement between the lid and the current collector. It becomes possible to do.

  The first engagement portion may include a protrusion that protrudes toward the power generation element, and the second engagement portion may include a hole that engages with the protrusion in a fitted state.

  According to this, not only the first object can be achieved but also the second object can be achieved. That is, since the first engagement portion and the second engagement portion are engaged in the space between the power generation element and the lid body, the outer space of the lid body in which the electrode terminals are arranged can be made compact. . Furthermore, since the second engagement portion is a hole, the second engagement portion can receive the protruding portion of the first engagement portion without protruding toward the power generation element side. Therefore, the space between the lid and the power generation element can also be made compact, and the ratio of the power generation element to the internal volume of the casing constituted by the container and the lid can be improved.

  In addition, providing the current collector with a hole as the second engaging portion can contribute to reducing the weight of the power storage element.

  Furthermore, it is a plate-like member formed of an insulator, and has a third engagement portion that engages with the first engagement portion on one surface side, and engages with the second engagement portion on the other surface side. An insulating member having a mating fourth engaging portion may be provided.

  The insulating member may further include an insertion hole penetrating in the thickness direction through which the fastening member is inserted.

  According to this, it is not necessary to insulate the lid and the like, and it is possible to easily ensure the insulation state between the lid and the current collector. In addition, the insulating member can be easily positioned by engaging the first engaging portion and the third engaging portion. Furthermore, the force that the current collector tends to shift with respect to the lid is applied to the insulating member in the compression direction, so even a thin insulating member with low rigidity can sufficiently resist the force. .

  The lid includes a recessed portion that is recessed toward the power generating element on the opposite side of the protruding portion with respect to the lid, and further includes a connection terminal that is partially disposed in the fitted state in the recessed portion. May be.

  According to this, the structure for preventing the rotation of the connection terminal is arranged at the portion where the first engagement portion and the second engagement portion are engaged without protruding the lid body on the side where the electrode terminal is arranged. can do. Therefore, it is possible to provide the connection terminal while maintaining the compactness of the power storage element.

  According to the present invention, it is possible to easily and firmly suppress the deviation of the current collector with respect to the lid that occurs during assembly. In addition, it is possible to provide a large-capacity and compact power storage element by improving the ratio of the power generation element to the entire size of the power storage element.

FIG. 1 is a perspective view showing an external appearance of the power storage device of the present embodiment. FIG. 2 is a perspective view schematically showing the inside of the electricity storage device with a part of the container omitted. FIG. 3 is an exploded perspective view schematically showing the vicinity of the current collector in an exploded state. FIG. 4 is an exploded perspective view schematically showing the vicinity of the current collector in a disassembled state with a line of sight opposite to FIG. 3. FIG. 5 is a cross-sectional view schematically showing the vicinity of the current collector in cross section. FIG. 6 is an exploded perspective view schematically showing the vicinity of the current collector on the positive electrode side in an exploded state.

  Next, an embodiment of a power storage device according to the present invention will be described with reference to the drawings. In addition, the following embodiment is only what showed an example of the electrical storage element which concerns on this invention. Accordingly, the scope of the present invention is defined by the wording of the claims with reference to the following embodiments, and is not limited to the following embodiments.

  FIG. 1 is a perspective view showing an external appearance of the power storage device of the present embodiment.

  FIG. 2 is a perspective view schematically showing the inside of the electricity storage device with a part of the container omitted.

  FIG. 3 is an exploded perspective view schematically showing the vicinity of the current collector in an exploded state.

  FIG. 4 is an exploded perspective view schematically showing the vicinity of the current collector in a disassembled state with a line of sight opposite to FIG. 3.

  As shown in these drawings, the electricity storage element 100 according to the present embodiment is a non-aqueous electrolyte secondary electricity storage element that can charge and discharge electricity, and includes a power generation element 101 and a container 102. A lid 103, a current collector 104, an electrode terminal 105, and a fastening member 106. Further, in the case of the present embodiment, power storage element 100 includes insulating member 107, connection terminal 108, and second insulating member 109.

  In the present embodiment, the power generation element 101 is a member that can store electricity, including a separator, a negative electrode, and a positive electrode, although detailed illustration is omitted. The negative electrode is formed by forming a negative electrode active material layer on the surface of a long strip negative electrode current collector foil made of copper, for example. The positive electrode is obtained by forming a positive electrode active material layer on the surface of a long belt-shaped positive electrode current collector foil made of aluminum, for example. The separator is, for example, a microporous sheet made of resin. The power generation element 101 is a so-called flat wound type formed by winding a layered arrangement so that a separator is sandwiched between a negative electrode and a positive electrode so that the whole is formed into an oval shape in the length direction. Power generation element.

  The container 102 is a rectangular (cuboid) box that houses the power generation element 101. The container 102 is made of aluminum or an alloy thereof or a thin stainless steel for reducing the weight. The container 102 includes a rectangular bottom portion, a rectangular long wall portion erected on each long side portion of the bottom portion, and a rectangular short wall portion erected on each short side portion of the bottom portion. In addition, the container 102 forms a casing together with the lid 103 by welding the opening end of the container 102 and the lid 103.

  The lid 103 is a metal plate-like member that closes the opening of the container 102 and includes a first engagement portion 131. In the case of the present embodiment, the first engaging portion 131 is a protruding portion that protrudes toward the power generation element 101 and has a rectangular shape (square). The first engagement portion 131 is a portion formed by pressing a plate-shaped metal member, and corresponds to the protrusion on the opposite side of the protrusion (first engagement portion 131) with respect to the lid 103. The portion is provided with a recessed portion 132 that is recessed toward the power generation element 101. The recessed portion 132 is formed at the same time when the protruding portion is formed by press working.

  The current collector 104 is a member that is electrically connected to the electrode terminal 105 and the power generation element 101 and is also physically (mechanically) connected to the lid 103, and is fitted to the first engagement portion 131. A second engagement portion 142 that engages in the combined state is provided. In the case of the present embodiment, the second engagement portion 142 is a hole that penetrates in the thickness direction and engages with the protruding portion (first engagement portion 131).

  The current collector 104 is a metal plate-like member disposed in a bent state along the short wall portion and the lid body 103 from the lid body 103 to the short wall portion of the container 102. The current collector 104 is fixedly connected to the lid 103 together with the electrode terminal 105 by the connection terminal 108, and is fixed to the negative electrode or the positive electrode of the power generation element 101 by welding or the like and electrically connected thereto. ing. Thereby, the power generation element 101 is held by the current collector 104 inside the housing.

  The current collector 104 attached to the negative electrode of the power generation element 101 is made of copper, and the current collector 104 attached to the positive electrode is made of aluminum.

  Further, the method of joining the current collector 104 to the negative electrode current collector foil or the positive electrode current collector foil of the power generation element 101 is not particularly limited, but in this embodiment, the welding fin 145 is used as the current collector. A method is adopted in which a part of 104 is erected by being bent and joined by welding while sandwiching the negative electrode current collector foil or the positive electrode current collector foil of the power generation element 101 with the fins 145.

  Here, the fitting state of the first engaging portion 131 and the second engaging portion 142 will be described with reference to FIG. FIG. 5 is a cross-sectional view schematically showing the vicinity of the current collector in cross section.

  As shown in the figure, the protruding portion that is the first engaging portion 131 of the lid 103 is arranged in a state of being inserted in the Z-axis direction into the hole that is the second engaging portion 142 of the current collector 104. This state is referred to as a fitted state. That is, the fitted state is a state where one of the projecting portions is inserted into the other of the through holes or the recesses (holes). When the first engaging portion 131 and the second engaging portion 142 are in the fitted state in this way, when the current collector 104 moves in the XY direction with respect to the lid 103, the first engaging portion 131 and Forces are generated in opposite directions within the same XY plane as the second engaging portion 142. Therefore, since the insulating member 107 disposed between the lid 103 and the current collector 104 is applied with a force in the compression direction and is not applied in the direction of torsion, it is sufficient even when the insulating member 107 is thin. It is possible to resist the force. In addition, even if a part of the lid 103 protrudes in the direction of the power generation element 101, the tip of the first engagement portion 131 (protrusion) is located within the thickness of the current collector 104. It is not necessary to widen the space between the lid 103 and the power generation element 101 in order to avoid the tip of the engaging portion 131 from touching the power generation element 101.

  The electrode terminal 105 leads the electricity stored in the power generation element 101 to the external space of the casing made up of the container 102 and the lid 103, and in the internal space of the casing in order to store electricity in the power generation element 101. It is a terminal for introducing electricity, and is a member provided on the opposite side of the current collector 104 with respect to the lid 103 and having conductivity. In the case of the present embodiment, since the lid 103 is made of metal, the second insulating member is insulated from the lid 103 and fills the gap between the lid 103 and seals the internal space of the housing. The electrode terminal 105 is attached to the lid 103 via 109.

  The fastening member 106 is a conductive member that connects the current collector 104 and the electrode terminal 105 in a state of being inserted through the lid 103. In the case of the present embodiment, the fastening member 106 is a metal rivet, a first attachment hole 143 provided in the current collector 104, an insertion hole 173 provided in the insulating member 107, and a second insertion provided in the lid 103. It is plastically deformed (caulked) by a tool that is pressed while rotating while being pierced through the hole 133, the third insertion hole 193 provided in the second insulating member 109, and the second attachment hole 153 provided in the electrode terminal 105. The current collector 104 and the electrode terminal 105 are physically (mechanically) fixed to the lid 103. Further, a second insulating member 109 is interposed between the fastening member 106 and the lid body 103, and the fastening member 106 electrically connects the current collector 104 and the electrode terminal 105 to the lid member 106. The body 103 is kept in an insulated state.

  The insulating member 107 is a plate-like member formed of an insulating material such as resin, and has a third engaging portion 174 that engages with the first engaging portion 131 on one surface side, and a third engaging portion 174 on the other surface side. This is a member having a fourth engagement portion 175 that engages with the second engagement portion 142. In the case of the present embodiment, the third engagement portion 174 has a concave shape that is fitted to the first engagement portion 131 (protruding portion). The fourth engagement portion 175 has a protruding shape that is inserted into the second engagement portion 142 (hole).

  The connection terminal 108 is a member for electrically and physically connecting the electrode terminal 105 and another member such as a bus bar or an electric wire. In the case of the present embodiment, the connection terminal 108 is a member that is partly disposed in the recessed portion 132 through the second insulating member 109 in a fitted state, and has a rectangular head corresponding to the rectangular recessed portion 132. It is a bolt that has.

  As described above, when a part of the connection terminal 108 is inserted into the recessed portion 132 formed in the lid 103 when the first engagement portion 131 is formed, the connection terminal protrudes from the surface of the lid 103. The protrusion amount of 108 can be suppressed, and a space necessary for connecting the power storage element 100 and another member can be reduced. Therefore, it is possible to provide a compact power storage element 100 that can be arranged even in a small space.

  According to the storage element 100, when the electrode terminal 105 and the current collector 104 are connected by the fastening member 106, the first engagement portion 131 of the lid 103 and the second engagement portion 142 of the current collector 104. Are engaged in a fitted state, so that the current collector 104 can be prevented from being displaced with respect to the lid 103 as much as possible. Therefore, the power generation element 101 connected to the current collector 104 is not distorted or unnecessary force is not applied, and the power generation element 101 can be maintained in a healthy state.

  In addition, since the thin insulating member 107 can be employed without providing protrusions on both surfaces of the insulating member 107, the thickness (Z-axis direction length) of the space in which the lid 103 and the current collector 104 are arranged is set. Since the thickness can be reduced, the ratio of the power generation element 101 to the inner volume of the container 102 can be improved. That is, it is possible to provide a compact and large-capacity storage element 100.

  In the above description, one electrode (positive electrode or negative electrode) has been described as an example, but the other electrode may have a similar structure. The other pole may have a different structure from the one pole.

  Further, the present invention is not limited to the above embodiment. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may be used as an embodiment of the present invention. In addition, the present invention includes modifications obtained by making various modifications conceivable by those skilled in the art without departing from the gist of the present invention, that is, the meaning described in the claims. It is.

  For example, the shape of the first engaging portion 131 and the recessed portion 132 is not limited to a rectangle, and may be a circle. However, if the shape of the first engagement portion 131 or the recessed portion 132 is non-circular (for example, a polygon or a substantially polygonal shape), when a part of the connection terminal 108 is inserted into the recessed portion 132, the connection terminal 108 is This is preferable because the rotation with the Z axis direction as the rotation axis is restricted with respect to the lid 103.

  The second engaging portion 142 does not need to be a hole and may be a concave portion. However, it is preferable to provide a through hole in the current collector 104 because the weight of the current collector 104 can be reduced.

  Further, although the first engagement portion 131 has a convex shape, the second engagement portion 142 may have a convex shape in a direction away from the power generation element 101, and the second engagement portion 142 may have a concave shape. In this case, the shape of the insulating member 107 or the second insulating member 109 may be the reverse of the above embodiment.

  In addition, in the case where an insulation process is performed on a necessary portion of the surface of the lid 103 or the current collector 104, the power storage element 100 does not need to include the insulating member 107 or the second insulating member 109.

  Further, when other members are directly welded to the electrode terminal 105, the power storage element 100 does not need to include the connection terminal 108.

  Further, the current collector 104 of one of the positive and negative electrodes (for example, the positive electrode) may be in contact with the lid 103 in a conductive state. In this case, as shown in FIG. 6, the insulating member 107 and the second insulating member 109 may not exist in the relationship between the positive electrode current collector 104 and the lid 103.

  The present invention can be used for a power storage element, and can be suitably used for a power storage element that requires a large current in a small space.

DESCRIPTION OF SYMBOLS 100 Power storage element 101 Electric power generation element 102 Container 103 Cover body 104 Current collector 105 Electrode terminal 106 Fastening member 107 Insulating member 108 Connection terminal 109 Second insulating member 131 First engaging part 132 Recessed part 133 Second insertion hole 142 Second engagement Joint portion 143 First attachment hole 145 Fin 153 Second attachment hole 173 Insertion hole 174 Third engagement portion 175 Fourth engagement portion 193 Third insertion hole

Claims (8)

A power generation element;
A container containing the power generation element;
A metal lid that closes the opening of the container and has a first engagement portion;
A current collector having a second engagement portion engaged with the first engagement portion in a fitted state;
An electrode terminal disposed on the opposite side of the current collector with respect to the lid;
A power storage device comprising: The first engaging portion includes a protruding portion that protrudes toward the power generation element,
The power storage element according to claim 1, wherein the second engaging portion includes a hole portion that engages with the protruding portion in a fitted state. The first engaging portion includes a protruding portion that protrudes toward the power generation element,
The power storage element according to claim 1, wherein the second engagement portion includes a recess that engages with the protrusion in a fitted state. further,
A plate-like member formed of an insulator, having a third engagement portion that engages with the first engagement portion on one surface side, and that engages with the second engagement portion on the other surface side. The electrical storage element of any one of Claims 1-3 provided with the insulating member which has a 4th engaging part. further,
The electrical storage element of any one of Claims 1-4 provided with the fastening member which connects the said electrical power collector and the said electrode terminal in the state penetrated by the said cover body. The insulating member further includes
The electrical storage element according to claim 5, further comprising an insertion hole penetrating in a thickness direction through which the fastening member is inserted. The lid includes a recessed portion that is recessed toward the power generation element on the opposite side of the protruding portion with respect to the lid.
Furthermore, the electrical storage element of any one of Claims 1-6 provided with the connecting terminal in which a part is arrange | positioned by the fitting state in the said recessed part. The electrical storage element according to claim 1, wherein the first engagement portion has a polygonal shape.

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