JP6786806B2 - Power storage element - Google Patents

Description

The present invention relates to a power storage element in which a current collector is attached to a container via an insulator.

In the power storage element, an electrode body and a current collector electrically connected to the electrode body are housed in a container (see, for example, Patent Document 1). Specifically, the container is provided with a container body that is partially opened to accommodate the electrode body and the current collector, and a lid plate that closes the container body, and a part of the current collector is provided. It is attached to the lid plate via an insulator. As a result, the insulation between the current collector and the lid plate is ensured.

Then, when assembling the power storage element, first, the insulator and the current collector are attached to the lid plate, and then the electrode body is connected to the current collector. After that, the electrode body, the current collector, and the insulator are inserted into the container body, and the lid plate is assembled and joined to the container body.

Japanese Unexamined Patent Publication No. 2014-26930

Here, in order to increase the storage capacity of the power storage element, it is desired to accommodate a larger electrode body in the container body without a gap. For this reason, for example, it is conceivable to bring the connection position between the electrode body and the current collector closer to the container body to fill the gap, but simply bringing them closer will bring the insulator closer to the container body. If the insulator is close to the container body, the insulator may interfere with the container body and be damaged when the lid plate is assembled to the container body.

Therefore, an object of the present invention is to provide a power storage element capable of increasing the size of the electrode body while suppressing damage to the insulator during assembly.

In order to achieve the above object, the current collecting element according to one aspect of the present invention is a current collecting element including a container composed of a first member and a second member and an electrode body housed in the container. A connection including a current collector housed in the current collector and electrically connected to the electrode body and an insulator provided between the current collector and the second member, and connected to the electrode body in the current collector. The portion is arranged at a position overlapping the wall portion facing the inner surface surface of the first member of the insulator, or on the inner side surface side of the position overlapping the wall portion.

According to this configuration, the connecting portion connected to the electrode body in the current collector is located on the inner surface of the insulator rather than the position where it overlaps the wall portion facing the inner surface of the first member or the position where it overlaps the wall portion. Since it is arranged on the side, the connecting portion can be brought closer to the inner surface of the first member while maintaining a certain clearance between the insulator and the first member. As a result, the electrode body can be made large while suppressing the insulator from interfering with the first member and being damaged during assembly.

Further, the current collector includes a connecting portion, a plate portion overlapped with an insulator, and a connecting portion for connecting the connecting portion and the plate portion, and the outer surface of the connecting portion is the outer surface of the plate portion and the connecting portion. Each of the outer surfaces of the above may be arranged inside the virtually extended intersection.

According to this configuration, since the outer surface of the connecting portion in the current collector is arranged inside the intersection where the outer surface of the plate portion and the outer surface of the connecting portion are virtually extended, the insulator is provided. It can be arranged away from the inner surface of the first member. In this way, if the insulator is separated from the inner surface of the first member, it becomes difficult to be bitten when the second member is assembled to the first member, and damage to the insulator can be suppressed.

The outer surface of the connecting portion of the current collector is arranged at a position closer to the inner surface of the first member than the connecting portion. Therefore, the electrode body can be arranged closer to the inner side surface of the first member than the end face of the insulator, and the electrode body can be enlarged by that amount.

Further, the insulator is provided with a wall portion that surrounds the end portion of the current collector on the second member side, and a housing portion that accommodates a part of the connecting portion is formed in the portion of the wall portion that corresponds to the connecting portion. You may be.

According to this configuration, since the accommodating portion is formed in the portion of the wall portion corresponding to the connecting portion, the connecting portion of the current collector can be arranged in the accommodating portion. As a result, the insulator can be arranged away from the inner side surface of the first member by the area where the accommodating portion and the connecting portion overlap, and the insulator and the first member can be further separated.

Further, a spacer interposed between the current collector and the electrode body and the first member may be provided, and the end portion of the spacer on the second member side may be arranged in the accommodating portion.

According to this configuration, since the end portion of the spacer on the second member side is arranged in the accommodating portion, the accommodating portion can be closed by the spacer. That is, the current collector exposed from the insulator by the accommodating portion can be covered with a spacer, and short-circuiting between the current collector and the first member can be suppressed.

Further, the end portion of the spacer on the second member side may have a shape corresponding to the accommodating portion.

According to this configuration, since the end portion of the spacer on the second member side has a shape corresponding to the accommodating portion, the entire accommodating portion can be closed by the end portion. Therefore, the entire current collector exposed from the insulator can be covered with a spacer, and short-circuiting between the current collector and the first member can be reliably suppressed.

Further, the connecting portion may have an inclined surface that gradually separates from the first member as it approaches the second member.

According to this configuration, since the connecting portion has an inclined surface that gradually separates from the first member as it approaches the second member, it is possible to prevent the connecting portion from being sharply narrowed. Therefore, it is possible to suppress a rapid increase in the current density of the current collector.

According to the present invention, it is possible to increase the size of the electrode body while suppressing damage to the insulator during assembly.

It is a perspective view which shows typically the appearance of the power storage element which concerns on embodiment. It is a perspective view which separates the container main body of the power storage element which concerns on embodiment, and shows each component which the power storage element has. It is a perspective view which shows the state which removed the side spacer from the electrode body of the power storage element which concerns on embodiment. It is a perspective view which shows the schematic structure of the lid plate which concerns on embodiment. It is sectional drawing which shows the fixed structure of the positive electrode terminal, the lid plate, the positive electrode 1st sealing member, the positive electrode 2nd sealing member and the like which concerns on embodiment. It is a side view which shows the engaging state of the positive electrode current collector which concerns on embodiment, and the positive electrode second sealing member. As a comparative example, it is sectional drawing which shows the positional relationship of the positive electrode current collector which does not have a connecting part, and the positive electrode second sealing member which does not have a notch part. It is sectional drawing which shows the positional relationship between the positive electrode current collector which concerns on modification 1 and the positive electrode second sealing member. It is sectional drawing which shows the positional relationship between the positive electrode current collector which concerns on modification 2 and the positive electrode second sealing member.

Hereinafter, the power storage element according to the embodiment of the present invention will be described with reference to the drawings. In addition, all the embodiments described below show a preferable specific example of the present invention. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes and their order, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept are described as arbitrary components.

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

FIG. 1 is a perspective view schematically showing the appearance of the power storage element 10 according to the embodiment. FIG. 2 is a perspective view showing each component of the power storage element 10 by separating the container 100 of the power storage element 10 according to the embodiment. FIG. 3 is a perspective view showing a state in which the side spacer 190 is removed from the electrode body 140 of the power storage element 10 according to the embodiment.

In these figures, the Z-axis direction is shown as the vertical direction, and the Z-axis direction may be described below as the vertical direction. However, depending on the usage mode, the Z-axis direction may not be the vertical direction. Therefore, the Z-axis direction is not limited to the vertical direction. The same applies to the following figures.

The power storage element 10 is a secondary battery capable of charging electricity and discharging electricity, and more specifically, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is not limited to the non-aqueous electrolyte secondary battery, and may be a secondary battery other than the non-aqueous electrolyte secondary battery, or may be a capacitor.

As shown in FIGS. 1 to 3, the power storage element 10 includes a container 100, a positive electrode terminal 200 and a negative electrode terminal 201, a positive electrode current collector 120 and a negative electrode current collector 130, a positive electrode first sealing member 150, and a negative electrode. It includes a first sealing member 160, a positive electrode second sealing member 170, a negative electrode second sealing member 180, an electrode body 140, and a pair of side spacers 190.

A liquid such as an electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100 of the power storage element 10, but the illustration of the liquid is omitted. The type of electrolytic solution sealed in the container 100 is not particularly limited as long as it does not impair the performance of the power storage element 10, and various types can be selected.

The container 100 is composed of a container body (first member) 111 having a rectangular tubular shape and a bottom, and a lid plate (second member) 110 which is a plate-shaped member that closes the opening of the container body 111. Further, the container 100 can be sealed inside by accommodating the positive electrode current collector 120, the negative electrode current collector 130, the electrode body 140 and the like inside, and then welding the lid plate 110 and the container body 111 or the like. It is possible. The material of the lid plate 110 and the container body 111 is not particularly limited, but is preferably a weldable metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate.

The electrode body 140 includes a positive electrode, a negative electrode, and a separator, and is a member capable of storing electricity. The positive electrode is a positive electrode active material layer formed on a positive electrode base material foil which is a long strip-shaped metal foil made of aluminum, an aluminum alloy, or the like. Further, the negative electrode is a negative electrode active material layer formed on a negative electrode base material foil which is a long strip-shaped metal foil made of copper, a copper alloy, aluminum, an aluminum alloy, or the like. The separator is a microporous sheet made of resin.

Here, as 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, any known material is appropriately known as long as it is a positive electrode active material or a negative electrode active material capable of storing and releasing lithium ions. Can be used.

The electrode body 140 is formed by winding what is arranged in a layer so that a separator is sandwiched between the negative electrode and the positive electrode, and is electrically connected to the positive electrode current collector 120 and the negative electrode current collector 130. Has been done. Although FIG. 2 shows the electrode body 140 having an oval cross section, it may have a circular shape or an elliptical shape. Further, the shape of the electrode body 140 is not limited to the winding type, and may be a laminated type in which flat plate-shaped electrode plates are laminated.

The positive electrode terminal 200 is an external terminal that is arranged outside the container 100 and is electrically connected to the positive electrode of the electrode body 140. Further, the negative electrode terminal 201 is an external terminal arranged outside the container 100 and electrically connected to the negative electrode body 140. That is, the positive electrode terminal 200 and the negative electrode terminal 201 lead the electricity stored in the electrode body 140 to the external space of the power storage element 10, and the electricity is stored in the internal space of the power storage element 10 in order to store electricity in the electrode body 140. It is a conductive electrode terminal for introducing. Further, the positive electrode terminal 200 and the negative electrode terminal 201 are attached to the lid plate 110 via the positive electrode first sealing member 150 and the negative electrode first sealing member 160.

The positive electrode current collector 120 and the negative electrode current collector 130 are arranged inside the container 100, that is, on the inner surface (the surface on the minus side in the Z-axis direction) of the lid plate 110. Specifically, the positive electrode current collector 120 is arranged between the positive electrode of the electrode body 140 and the side wall of the container body 111, and is electrically connected to the positive electrode terminal 200 and the positive electrode of the electrode body 140. It is a member having rigidity. The negative electrode current collector 130 is arranged between the negative electrode of the electrode body 140 and the side wall of the container body 111, and has conductivity and rigidity that are electrically connected to the negative electrode terminal 201 and the negative electrode of the electrode body 140. It is a member.

The positive electrode current collector 120 is made of aluminum, an aluminum alloy, or the like, like the positive electrode base material foil of the electrode body 140. Further, the negative electrode current collector 130 is made of copper, a copper alloy, or the like, like the negative electrode base material foil of the electrode body 140.

The positive electrode first sealing member 150 and the negative electrode first sealing member 160 are insulators in which at least a part thereof is arranged between the positive electrode terminal 200 and the negative electrode terminal 201 and the lid plate 110. Specifically, the positive electrode first sealing member 150 has an accommodating recess 151 having an open upper portion, and the positive electrode terminal 200 is accommodated in the accommodating recess 151. Similarly, the negative electrode first sealing member 160 has a recess 161 whose upper side is open, and the negative electrode terminal 201 is housed in the recess 161. As a result, the positive electrode terminal 200 and the negative electrode terminal 201 are attached to the lid plate 110 in a partially exposed state.

The positive electrode second sealing member 170 and the negative electrode second sealing member 180 are insulators in which at least a part thereof is arranged between the positive electrode current collector 120 and the negative electrode current collector 130 and the lid plate 110.

The pair of side spacers 190 cover the sides of the positive electrode current collector 120, the negative electrode current collector 130, and the electrode body 140, respectively, and are located between the positive electrode current collector 120, the negative electrode current collector 130, and the container body 111. It is an intervening insulator. That is, the side spacer 190 is a spacer that insulates the positive electrode current collector 120, the negative electrode current collector 130, the electrode body 140, and the container body 111. Further, the side spacer 190 is a member that positions the positive electrode current collector 120, the negative electrode current collector 130, and the electrode body 140 in the container body 111. The pair of side spacers 190 are formed long in the Z-axis direction. A recess 191 (see FIG. 5) extending along the longitudinal direction is formed on the surface of the side spacer 190 facing the electrode body 140. The positive electrode current collector 120, the negative electrode current collector 130, and the electrode body 140 are arranged in the recess 191.

Next, the lid plate 110 will be described.

FIG. 4 is a perspective view showing a schematic configuration of the lid plate 110 according to the embodiment.

As shown in FIG. 4, the lid plate 110 is a plate body having a substantially rectangular shape when viewed from above, and each corner portion thereof is formed in an R shape. In the following description, the “planar view” refers to a case where the upper surface (outer surface) of the lid plate 110 is viewed in a plan view.

The lid plate 110 is formed with a safety valve 112, a liquid injection port 113, a positive electrode terminal mounting portion 114, a negative electrode terminal mounting portion 115, two first bulging portions 116, and two second bulging portions 117.

The safety valve 112 is formed in a rectangular shape in a plan view at the central portion of the lid plate 110, and is formed thinner than the other portions. The safety valve 112 has a role of releasing the gas inside the container 100 by being opened when the internal pressure of the container 100 rises.

The liquid injection port 113 is a through hole for injecting an electrolytic solution at the time of manufacturing the power storage element 10. The liquid injection port 113 is closed by fitting a liquid injection plug (not shown) after injecting the electrolytic solution after the lid plate 110 is attached to the container body 111.

The positive electrode terminal mounting portion 114 is a portion to which the positive electrode terminal 200, the positive electrode first sealing member 150, the positive electrode second sealing member 170, and the positive electrode current collector 120 are mounted, and is formed at one end of the lid plate 110. .. The negative electrode terminal mounting portion 115 is a portion to which the negative electrode terminal 201, the negative electrode first sealing member 160, the negative electrode second sealing member 180, and the negative electrode current collector 130 are mounted, and is formed at the other end of the lid plate 110. There is.

Each of the two first bulging portions 116 is provided on the lid plate 110 because a part of the lid plate 110 is formed in a shape that bulges toward the outside of the container 100. Each of the two first bulging portions 116 is used for positioning the positive electrode first sealing member 150 or the negative electrode first sealing member 160.

Each of the two second bulging portions 117 is provided on the lid plate 110 because a part of the lid plate 110 is formed in a shape bulging toward the inside of the container 100. Each of the two second bulging portions 117 is used for positioning the positive electrode first sealing member 150 or the negative electrode first sealing member 160, and the positive electrode second sealing member 170 or the negative electrode second sealing member 180. Used for positioning.

Next, the fixing structures of the positive electrode terminal 200, the lid plate 110, the positive electrode current collector 120, the positive electrode first sealing member 150, the positive electrode second sealing member 170, and the like will be described in detail. Since the negative electrode side is almost the same as the positive electrode side, the description thereof will be omitted.

FIG. 5 is a cross-sectional view showing a fixed structure of the positive electrode terminal 200, the lid plate 110, the positive electrode first sealing member 150, the positive electrode second sealing member 170, and the like according to the embodiment. FIG. 5 is a cross-sectional view seen from the ZX plane including the VV line in FIG.

As shown in FIG. 5, the positive electrode terminal 200 is attached to the lid plate 110 in a state of being housed in the positive electrode first sealing member 150, and the positive electrode second sealing member 170 is further attached to the positive electrode first sealing member 150. By attaching the positive electrode current collector 120 via the positive electrode current collector 120, these are integrally fixed.

First, a specific configuration of each member will be described.

As shown in FIG. 5, the positive electrode terminal mounting portion 114 of the lid plate 110 includes a through hole 118 and a stepped portion 119.

The through hole 118 is a through hole having a circular shape in a plan view through which the shaft portion 220 of the positive electrode terminal 200 penetrates.

The step portion 119 is formed in a circular shape concentric with the through hole 118 so as to surround the entire circumference of the through hole 118, and the through hole 118 is formed in the center of the bottom portion thereof. That is, the step portion 119 is arranged on the outer peripheral portion of the through hole 118.

The first bulging portion 116 on the positive electrode side of the lid plate 110 is formed in the vicinity of the safety valve 112 side of the positive electrode terminal mounting portion 114. The first bulging portion 116 has a shape that bulges outward from one main surface of the lid plate 110. The first bulging portion 116 has a hollow shape with the other surface side open. The positive electrode first sealing member 150 is positioned by engaging the engaging recess 153a of the positive electrode first sealing member 150 with the first bulging portion 116.

The second bulging portion 117 on the positive electrode side of the lid plate 110 is formed in the vicinity of the side opposite to the first bulging portion 116 when viewed from the positive electrode terminal mounting portion 114. The second bulging portion 117 has a shape that bulges inward from the other main surface of the lid plate 110. The second bulging portion 117 has a hollow shape with the other surface side open. The positive electrode second sealing member 170 is positioned by engaging a part of the positive electrode second sealing member 170 with the second bulging portion 117. Further, the positive electrode first sealing member 150 is positioned by engaging the engaging convex portion 153b of the positive electrode first sealing member 150 with the hollow portion 117a of the second bulging portion 117.

The positive electrode terminal 200 integrally includes a bus bar connecting portion 210 and a shaft portion 220.

The bus bar connecting portion 210 is a terminal body to which a bus bar (not shown) connecting the electrode terminals of the power storage element 10 is connected, and the upper surface thereof is formed to be flat. Further, a pedestal 210a projecting downward is formed on the lower surface of the bus bar connecting portion 210. The pedestal 210a is formed in a shape that fits in the stepped portion 119 of the lid plate 110 in a plan view. In the bus bar connecting portion 210, the portion where the pedestal 210a is located is thicker than the other portions. Therefore, when the bus bar is welded to the bus bar connecting portion 210, the heat capacity can be secured by the pedestal 210a.

The shaft portion 220 is a conductive member connected to the bus bar connecting portion 210 which is a terminal body. The shaft portion 220 extends downward from the lower surface of the pedestal 210a, and by crimping the tip portion 230, the positive electrode first sealing member 150 and the positive electrode second sealing member 170 are attached to the lid plate 110. The positive electrode current collector 120 is fixed. The tip portion 230 of the shaft portion 220 is a caulking portion and is arranged inside the container 100. The tip portion 230 has an annular shape when viewed in a plan view and is in close contact with the surface of the current collector main body portion 121. The tip portion 230 and the bus bar connecting portion 210 connect the current collector main body 121 of the positive electrode current collector 120, the positive electrode first sealing member 150, the positive electrode second sealing member 170, and the lid plate 110 on the Z axis. It is tightened by sandwiching it in the direction.

The positive electrode first sealing member 150 integrally includes a terminal accommodating portion 153 and a cylindrical portion 152.

The terminal accommodating portion 153 is formed with a concave recess 151 accommodating the bus bar connecting portion 210 of the positive electrode terminal 200.

The cylindrical portion 152 projects downward from the lower surface of the terminal accommodating portion 153 in a cylindrical shape. The through hole 154 of the cylindrical portion 152 has the same shape as the through hole 123 of the positive electrode current collector 120. The through holes 154 are arranged so as to be continuous with the through holes 123 of the positive electrode current collector 120, and the shaft portion 220 of the positive electrode terminal 200 is inserted into these through holes 154 and 123. The outer diameter of the cylindrical portion 152 is formed to be large enough to be inserted into the through holes 172 and 118.

Further, an engaging recess 153a that engages with the first bulging portion 116 of the lid plate 110 is formed on the bottom surface of the end portion of the terminal accommodating portion 153 on the safety valve 112 side. On the other hand, on the bottom surface of the end portion of the terminal accommodating portion 153 opposite to the engaging recess 153a, an engaging convex portion 153b that engages with the hollow portion 117a of the second bulging portion 117 of the lid plate 110 is formed. There is. Since the engaging recess 153a engages with the first bulging portion 116 and the engaging convex portion 153b engages with the hollow portion 117a of the second bulging portion 117, the positive electrode first sealing member 150 is provided at two locations. It is positioned.

The positive electrode first sealing member 150 is preferably made of an insulating member having a lower rigidity than the lid plate 110. The positive electrode first sealing member 150 is made of, for example, a resin such as polyolefin, polyphenylene sulfide (PPS), polypropylene (PP), fluororesin (PFA), or phenol resin. Further, the positive electrode first sealing member 150 may be formed of other resin, or may be formed of a resin mixed with fibers such as glass fiber. Further, the positive electrode first sealing member 150 may have a structure composed of two or more members made of different resin materials. In this case, the resin material of the portion of the insulating member that ensures airtightness may be PFA or the like, and the resin material of the portion that requires structural strength may be ABS, polybutylene terephthalate (PBT), polyamide (also referred to as nylon) or the like. ..

FIG. 6 is a side view showing an engaged state between the positive electrode current collector 120 and the positive electrode second sealing member 170 according to the embodiment.

As shown in FIGS. 5 and 6, the positive electrode second sealing member 170 is elongated in the X-axis direction and is formed in a substantially rectangular parallelepiped shape with the lower side open.

The current collector main body 121 of the positive electrode current collector 120 is fixed to the bottom surface of the positive electrode second sealing member 170. Further, a wall portion 171 surrounding the entire circumference of the current collector main body portion 121 is formed on the bottom surface of the positive electrode second sealing member 170. Here, the portions of the wall portion 171 that face each other in the longitudinal direction are referred to as the first side wall 171a and the second side wall 171b, and the portions that face each other in the lateral direction are referred to as the third side wall 171c and the fourth side wall 171d. The first side wall 171a faces the short side surface of the container body 111, and the second side wall 171b is arranged inside the container body 111. The third side wall 171c and the fourth side wall 171d face each other of a pair of long side surfaces of the container body 111.

A notch (accommodation portion) 174 is formed at the end of the wall portion 171 on the short side surface side of the container body 111. Specifically, the cutout portion 174 is cut out so that the entire first side wall 171a is lower than the other side walls 171b, 171c, 171d, and the first side wall in the third side wall 171c and the fourth side wall 171d. The end portion on the 171a side is cut out so as to form a concave curved surface dented toward the lid plate 110. The end portion 192 of the side spacer 190 on the lid plate 110 side is housed in the notch portion 174. Specifically, the end portion 192 on the lid plate 110 side of the side spacer 190 is formed in a shape corresponding to the notch portion 174, whereby the entire notch portion 174 is formed at the end portion 192 of the side spacer 190. Is blocked by. Here, the "shape corresponding to the notch portion 174" is a shape capable of closing the entire notch portion 174. For example, the shape in which the end portion 192 is accommodated and fitted in the notch portion 174 as a whole, or the end portion 192 is partially accommodated in the notch portion 174 and other portions are lateral to the notch portion 174. The shape that covers the

Further, on the upper surface of the positive electrode second sealing member 170 (the surface on the lid plate 110 side), an engaging recess 173 with which the second bulging portion 117 engages is provided at a position facing the second bulging portion 117. It is formed. Since the second bulging portion 117 engages with the engaging recess 173, the positive electrode second sealing member 170 is positioned.

As shown in FIG. 5, in the positive electrode second sealing member 170, a through hole 172 having the same shape as the through hole 118 of the lid plate 110 is formed. The through holes 172 are arranged so as to be continuous with the through holes 118 of the lid plate 110, and the cylindrical portion 152 of the positive electrode first sealing member 150 is inserted into these through holes 172 and 118. The shaft portion 220 of the positive electrode terminal 200 is inserted inside the cylindrical portion 152. As described above, the shaft portion 220 of the positive electrode terminal 200 penetrates the lid plate 110 through the through hole 118 together with the cylindrical portion 152 of the positive electrode first sealing member 150 which is an insulator.

The positive electrode second sealing member 170 is preferably made of an insulating member having a lower rigidity than the lid plate 110. The positive electrode second sealing member 170 is made of, for example, a resin such as PPS, PP, PE, PBT, PFA, or PEEK.

As shown in FIGS. 3, 5 and 6, the positive electrode current collector 120 integrally includes the current collector main body 121 and the legs 122 with respect to the current collector main body 121. The pair of legs 122 are formed by bending.

The current collector main body 121 is a plate portion to which the positive electrode terminal 200 is connected and is overlapped with the positive electrode second sealing member 170. Specifically, the current collector main body 121 is formed in a flat plate shape and is arranged to face the lid plate 110. The current collector main body 121 has a through hole 123 into which the shaft 220 of the positive electrode terminal 200 is inserted.

The leg portion 122 is two long legs electrically connected to the positive electrode body 140 (only one is shown in FIGS. 3 and 5). Specifically, the leg portion 122 is formed in a flat plate shape and is arranged to face the long side surface of the container main body 111. Further, the leg portion 122 is arranged on the outer side (minus side in the X-axis direction) of the through hole 123 of the current collector main body portion 121. The leg portion 122 is fixed to the positive electrode body 140 with the positive electrode body 140 sandwiched in the Y-axis direction (see FIG. 3).

The leg portion 122 includes a connecting portion 124 that is electrically connected to the positive electrode of the electrode body 140, and a connecting portion 125 that connects the connecting portion 124 and the current collector main body portion 121.

Then, as shown in FIGS. 5 and 6, the outer surface 126 of the connecting portion 125 on the lid plate 110 side facing the short side surface of the container main body 111 is separated from the container main body 111 by the connecting portion 124. It is formed in a concave shape that is recessed so as to be. Specifically, the outer surface 126 is an inclined surface that is inclined so as to gradually move away from the inner side surface (short side surface) of the container body 111 as it approaches the lid plate 110. As described above, the outer surface 126 is arranged inside the intersection P where each of the outer surface of the current collector main body 121 and the outer surface of the connecting portion 124 is virtually extended. Here, the outer surface of the current collector main body 121 is a flat surface that overlaps the positive electrode second sealing member 170. The outer surface of the connecting portion 124 is a flat surface facing the inner surface of the container body 111.

The connecting portion 125 may be a flat surface or a curved surface.

In the region where each of the outer surface of the current collector main body 121 and the outer surface of the connection portion 124 is virtually extended, an end surface of the positive electrode second sealing member 170 facing the short side surface of the container main body 111 is arranged. Has been done. Specifically, the end surface of the positive electrode second sealing member 170 on the first side wall 171a side is arranged in the region. As a result, the positive electrode second sealing member 170 is arranged farther from the container main body 111 than the connecting portion 124 of the positive electrode current collector 120.

Further, a part of the connecting portion 125 is housed in the cutout portion 174 of the positive electrode second sealing member 170. Specifically, a part of the connecting portion 125 is housed in a portion of the notch portion 174 corresponding to the first side wall 171a. As a result, the positive electrode second sealing member 170 can be arranged away from the inner side surface of the container body 111 by the region where the notch portion 174 and the connecting portion 125 overlap, and the positive electrode second sealing member 170 and the positive electrode second sealing member 170 can be arranged. The container body 111 can be separated from the container body 111.

Next, a method of manufacturing the power storage element 10 according to the present embodiment will be described.

First, the flat plate to be the positive electrode current collector 120 is die-cut into a desired shape in advance, and then the leg portion 122 is bent with respect to the current collector main body portion 121 to form the positive electrode current collector 120.

After that, the positive electrode second sealing member 170 is superposed on the upper surface of the current collector main body 121 of the positive electrode current collector 120, and the lid plate 110 is superposed on the upper surface of the positive electrode second sealing member 170. Further, after assembling the positive electrode first sealing member 150 on the upper surface of the lid plate 110, the positive electrode terminal 200 is housed in the recess 151 of the positive electrode first sealing member 150. At this time, the shaft portion 220 of the positive electrode terminal 200 penetrates through the through hole 154 of the positive electrode first sealing member 150, and by crimping the shaft portion 220, the positive electrode first seal is as shown in FIG. The stop member 150, the positive electrode second sealing member 170, the positive electrode current collector 120, and the positive electrode terminal 200 are attached to the lid plate 110.

Further, on the negative electrode side, the negative electrode first sealing member 160, the negative electrode second sealing member (not shown), the negative electrode current collector 130, and the negative electrode terminal 201 are attached to the lid plate 110 in the same procedure.

After that, the positive electrode of the electrode body 140 is attached to the positive electrode current collector 120, and the negative electrode of the electrode body 140 is attached to the negative electrode current collector 130.

After that, from the state shown in FIG. 2, the electrode body 140, the side spacer 190, and the like are housed in the container body 111 of the container 100, and the lid plate 110 is assembled. At this time, as described above, the positive electrode second sealing member 170 is separated from the short side surface of the container body 111 with respect to the connecting portion 124 of the positive electrode current collector 120. As a result, the positive electrode second sealing member 170 is prevented from interfering with the container body 111 and the lid plate 110.

After that, the lid plate 110 is welded to the container body 111 to assemble the container 100. Next, after injecting the electrolytic solution from the liquid injection port 113, the liquid storage element 10 shown in FIG. 1 is manufactured by welding the liquid injection plug to the lid plate 110 to close the liquid injection port 113.

FIG. 7 is a cross-sectional view showing the positional relationship between the positive electrode current collector 120A having no inclined surface and the positive electrode second sealing member 170A having no notch as a comparative example. In the following description, the same parts as those in the above embodiment may be designated by the same reference numerals and the description thereof may be omitted. Further, in FIG. 7, the side spacer is omitted.

The positive electrode current collector 120A does not have an inclined surface, and the leg portions 122a extend vertically from the current collector main body portion 121a. Therefore, the first side wall 171a of the positive electrode second sealing member 170A protrudes from the positive electrode current collector 120A and is closer to the container body 111 than the positive electrode current collector 120A. As described above, if the positive electrode second sealing member 170A is close to the container body 111, the positive electrode second sealing member 170A may interfere with the container body 111 and the lid plate 110 during assembly and be damaged.

As described above, according to the present embodiment, the connection portion 124 connected to the electrode body 140 in the positive electrode current collector 120 is a container rather than the position where it overlaps the first side wall 171a of the positive electrode second sealing member 170. It is arranged on the inner side surface side of the main body 111. As a result, the connecting portion 124 can be brought closer to the inner surface of the container body 111 while maintaining a certain clearance between the positive electrode second sealing member 170 and the container body 111. As a result, the electrode body 140 can be made large while suppressing the positive electrode second sealing member 170 from interfering with the container body 111 and being damaged during assembly.

Further, since the outer surface 126 of the connecting portion 125 is arranged inside the intersection P where each of the current collector main body portion 121 and the outer surface of the connecting portion 124 is virtually extended, the positive electrode second sealing member The 170 can be arranged further away from the inner surface of the container body 111. If the positive electrode second sealing member 170 is separated from the inner side surface of the container body 111 in this way, it becomes difficult to be bitten when the lid plate 110 is assembled to the container body 111, and damage to the positive electrode second sealing member 170 is suppressed. can do.

The outer surface of the connecting portion 124 of the positive electrode current collector 120 is arranged at a position closer to the inner side surface of the container body 111 than the connecting portion 125. Therefore, the electrode body 140 can be arranged closer to the inner side surface of the container body 111 than the end surface of the positive electrode second sealing member 170, and the electrode body 140 can be made larger by that amount.

Further, by providing the connecting portion 125, it is not necessary to condense each of the positive electrode second sealing member 170, the container body 111, and the positive electrode current collector 120. As a result, a clearance can be provided between the members. Therefore, when the positive electrode current collector 120 is ultrasonically welded to the electrode body 140, it is possible to prevent the ultrasonic welding from adversely affecting the positive electrode second sealing member 170 and the positive electrode current collector 120.

Further, since the cutout portion 174 is formed in the portion of the wall portion 171 corresponding to the connecting portion 125, the connecting portion 125 of the positive electrode current collector 120 can be arranged in the cutout portion 174. As a result, the positive electrode second sealing member 170 can be arranged away from the inner side surface of the container body 111 by the region where the notch portion 174 and the connecting portion 125 overlap, and the positive electrode second sealing member 170 and the positive electrode second sealing member 170 can be arranged. The container body 111 can be separated from the container body 111.

Further, since the end portion 192 on the lid plate 110 side of the side spacer 190 is arranged in the notch portion 174, the notch portion 174 can be closed by the side spacer 190. That is, the positive electrode current collector 120 exposed from the positive electrode second sealing member 170 by the notch portion 174 can be covered with the side spacer 190, and the short circuit between the positive electrode current collector 120 and the container body 111 is suppressed. be able to.

Further, since the end portion 192 of the side spacer 190 has a shape corresponding to the notch portion 174, the entire notch portion 174 can be closed by the end portion 192. Therefore, even in the cutout portion 174, the end portion 192 of the side spacer 190 covers the positive electrode current collector 120, and it is possible to reliably suppress the short circuit between the positive electrode current collector 120 and the container body 111. ..

Further, since the connecting portion 125 has an inclined surface (outer surface 126) that gradually separates from the container body 111 as it approaches the lid plate 110, the connecting portion 125 of the positive electrode current collector 120 has a shape that sharply narrows. Can be suppressed. Therefore, it is possible to prevent the current density of the positive electrode current collector 120 from rapidly increasing.

(Modification example 1)
Next, a modification 1 according to the above embodiment will be described. In the above embodiment, the positive electrode second sealing member 170 provided with the notch portion 174 has been illustrated and described. In the first modification, a case where the positive electrode second sealing member 170B having no notch and the positive electrode current collector 120 whose outer surface 126 of the connecting portion 125 is an inclined surface will be described.

FIG. 8 is a cross-sectional view showing the positional relationship between the positive electrode current collector 120 according to the first modification and the positive electrode second sealing member 170B.

As shown in FIG. 8, the positive electrode second sealing member 170B is not formed with a notch, and is provided with a uniform wall portion 171B as a whole. The first side wall 171a of the wall portion 171B is arranged at a position facing the outer surface 126 of the positive electrode current collector 120. As a result, the positive electrode second sealing member 170B is arranged farther from the container main body 111 than the connection portion 124 of the positive electrode current collector 120. As described above, even if the positive electrode second sealing member 170B has no notch, if the outer surface 126 which is an inclined surface is formed on the positive electrode current collector 120, the positive electrode second sealing member 170B can be removed from the container body 111. Can be placed apart. As a result, damage to the positive electrode second sealing member 170 due to interference with the container 100 can be suppressed.

Further, the connecting portion 124 may be arranged on the inner side surface side of the container main body 111 from a position where the connecting portion 124 overlaps the first side wall 171a of the wall portion 171B in a plan view. Specifically, it may be arranged on the inner side surface side of the container main body 111 rather than the inner surface 1711 of the first side wall 171a. That is, the connecting portion 124 may be arranged at a position where it overlaps the first side wall 171a of the wall portion 171B in a plan view.

(Modification 2)
Next, a modification 2 according to the above embodiment will be described. In the above embodiment, the case where the outer surface 126 of the connecting portion 125 is an inclined surface has been illustrated and described. In this modification 2, the case where the connecting portion 125c is a stepped portion will be described.

FIG. 9 is a cross-sectional view showing the positional relationship between the positive electrode current collector 120C according to the second modification and the positive electrode second sealing member 170.

As shown in FIG. 9, the connecting portion 125c of the positive electrode current collector 120C has a concave step portion that is recessed in a portion facing the short side surface of the container main body 111 so as to be separated from the container main body 111 by the connecting portion 124. 127 is formed. Specifically, the step portion is a rectangular concave portion. In this way, even if the connecting portion 125c has the stepped portion 127, the end surface of the positive electrode second sealing member 170 on the first side wall 171a side can be arranged in the stepped portion 127, and the positive electrode second sealing member 170 can be arranged. The member and the container body 111 can be arranged apart from each other.

Although the power storage element according to the embodiment of the present invention and its modified example has been described above, the present invention is not limited to the above-described embodiment and its modified example. That is, it should be considered that the embodiments disclosed this time and examples thereof are examples in all respects and are not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the scope of claims are included.

For example, in the above-described embodiment and its modification, the power storage element 10 is provided with one electrode body 140, but a configuration including a plurality of electrode bodies may be used.

Further, in the above-described embodiment and its modification, the positive electrode terminal 200 in which the bus bar connecting portion 210 and the shaft portion 220 are integrally molded is illustrated, but the bus bar connecting portion and the shaft portion are separate bodies before assembly. It may be a positive electrode terminal that is integrated after assembly. In this case, the shaft portion of the member separate from the bus bar connecting portion becomes the conductive member.

Further, in the above embodiment, the case where the shaft portion 220 of the positive electrode terminal 200 is crimped and fastened to the positive electrode current collector 120 is illustrated, but it may be fastened by screwing.

Further, in the above embodiment, the case where the outer surface 126, which is an inclined surface, is formed on the end portion of the positive electrode current collector 120 on the lid plate 110 side and facing the short side surface of the container body 111 is exemplified. did. However, the inclined surface may be formed at the end portion of the positive electrode current collector 120 on the lid plate 110 side and facing the long side surface of the container body 111. As a result, the positive electrode second sealing member can be arranged away from the long side surface of the container body 111.

Further, in the above embodiment, of the first member and the second member forming the container 100, the first member is exemplified as the container main body 111, and the second member is exemplified as the lid plate 110. However, the first member and the second member are not limited thereto. For example, both the first member and the second member may be a box-shaped housing that is partially open.

Further, in the above-described embodiment, the positive electrode side is illustrated to explain the specific configuration of the characteristic portion of the present invention, but it goes without saying that the same configuration is applied to the negative electrode side as well. The positive electrode side and the negative electrode side may have different configurations as long as they do not deviate from the gist of the present invention.

In addition, a form constructed by arbitrarily combining the above-described embodiment and the above-mentioned modification is also included in the scope of the present invention.

The present invention can be applied to a power storage element such as a lithium ion secondary battery.

10 Power storage element 100 Container 110 Lid plate (second member)
111 Container body (first member)
112 Safety valve 113 Liquid injection port 114 Positive electrode terminal mounting part 115 Negative electrode terminal mounting part 116 First bulging part 117 Second bulging part 117a Hollow part 118, 123, 154, 172 Through hole 119 Stepped part 120, 120A, 120C Positive electrode collection Current collector 121,121a Current collector body (plate)
122, 122a Leg 124 Connection 125, 125c Connection 126 Outer surface (inclined surface)
130 Negative electrode current collector 140 Electrode body 150 Positive electrode 1st sealing member 151,161 Containment recess 152 Cylindrical part 153 Terminal accommodating part 153a Engagement recess 153b Engagement convex part 160 Negative electrode 1st sealing member 170, 170A, 170B Positive electrode No. 2 Sealing member (insulator)
171, 171B Wall 171a 1st side wall 171b 2nd side wall 171c 3rd side wall 171d 4th side wall 173 Engagement recess 174 Notch part (accommodation part)
180 Negative electrode second sealing member 190 Side spacer (spacer)
191 Recess 192 End 200 Positive electrode terminal 201 Negative electrode terminal 210 Busbar connection 210a Pedestal 220 Shaft 230 Tip

Claims (7)

A power storage element including a container composed of a first member and a second member and an electrode body housed in the container.
A current collector housed in the container and electrically connected to the electrode body,
An insulator provided between the current collector and the second member is provided.
The insulator has a wall portion that protrudes from the bottom surface to which the current collector is fixed and faces the inner side surface of the first member.
At the connecting portion to be connected to the electrode body in the current collector, the opposite outer surface to the inner surface of the first member is positioned overlapping the front Kikabe portion, or the inner surface side of a position overlapping the wall portion Is located in
The wall portion is a power storage element that projects inward from the lowermost surface of the second member. The current collector includes the connecting portion, a plate portion overlapped with the insulator, and a connecting portion for connecting the connecting portion and the plate portion.
The power storage element according to claim 1, wherein the outer surface of the connecting portion is arranged inside the intersection where the outer surface of the plate portion and the outer surface of the connecting portion are virtually extended. The insulator includes a wall portion that surrounds an end portion of the current collector on the second member side.
The power storage element according to claim 2, wherein a housing portion for accommodating a part of the connecting portion is formed in a portion of the wall portion corresponding to the connecting portion. further,
A spacer interposed between the current collector and the electrode body and the first member is provided.
The power storage element according to claim 3, wherein the end portion of the spacer on the second member side is arranged in the accommodating portion. The power storage element according to claim 4, wherein the end portion of the spacer on the second member side has a shape corresponding to the accommodating portion. The accommodating portion is a notch portion recessed toward the second member side.
The power storage element according to claim 5, wherein the end portion of the spacer on the second member side is housed in the notch portion. The power storage element according to any one of claims 2 to 6, wherein the connecting portion has an inclined surface that gradually separates from the first member as it approaches the second member.

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