JP2018056099A - Power storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element in which the risk of short circuit of positive and negative electrode plates of an electrode body can be reduced, even when the power storage element was not used normally.SOLUTION: In a power storage element including an electrode body where a positive electrode plate and a negative electrode plate are laminated, and an electrode terminal connected with the electrode body, at least one of the positive and negative electrode plates has a body, and a connection extending in the first direction from one end of the body and connected with the electrode terminal. In a range of the body where the positive and negative electrode plates are overlapped in the first direction, a difference between widths of the positive and negative electrode plates in a second direction orthogonal to the first direction is larger in the other end than in an intermediate part between one and the other ends.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an energy storage device including an electrode body in which a positive electrode plate and a negative electrode plate are laminated, and an electrode terminal connected to the electrode body.

  In an electric storage element including an electrode body in which a positive electrode plate and a negative electrode plate are laminated, it is important to prevent a short circuit between the positive electrode plate and the negative electrode plate, and conventionally, a configuration for preventing the short circuit has been proposed. For example, Patent Document 1 discloses that the protruding amount of the separator from the negative electrode plate at the positive electrode non-coated portion side end of the electrode body is twice the protruding amount of the separator from the positive electrode plate at the negative electrode non-coated portion side end. As described above, a power storage element (secondary battery) that can prevent a short circuit even when the temperature of the battery is increased due to overcharging or the like and the separator is thermally contracted is disclosed.

JP 2012-43752 A

  However, in the configuration such as the conventional power storage element, there is a possibility that the positive electrode plate and the negative electrode plate of the electrode body may be short-circuited when used abnormally. That is, in the conventional power storage element as described above, the position of the electrode plate may be shifted due to an abnormal use, and in this case, the positive electrode plate and the negative electrode plate may be short-circuited.

  The present invention has been made in view of the above problems, and provides a power storage device that can further reduce the risk of short-circuiting between the positive electrode plate and the negative electrode plate of the electrode body even when used abnormally. For the purpose.

  In order to achieve the above object, a power storage device according to one embodiment of the present invention is a power storage device including an electrode body in which a positive electrode plate and a negative electrode plate are stacked, and an electrode terminal connected to the electrode body. And at least one of the positive electrode plate and the negative electrode plate has a main body portion and a connection portion extending in a first direction from one end portion of the main body portion and connected to the electrode terminal, In the range where the positive electrode plate and the negative electrode plate in the first direction overlap, the difference in width between the negative electrode plate and the positive electrode plate in the second direction orthogonal to the first direction is the one end and the other end. The other end portion is formed larger than the intermediate portion therebetween.

  According to the present invention, it is possible to provide a power storage device that can further reduce the risk of short-circuiting between the positive electrode plate and the negative electrode plate of the electrode body even when used abnormally.

It is a perspective view which shows the external appearance of the electrical storage element which concerns on embodiment. It is a disassembled perspective view which decomposes | disassembles the electrical storage element which concerns on embodiment, and shows each component. It is sectional drawing which shows the internal structure of the electrical storage element which concerns on embodiment. It is a top view which shows the structure of the electrode body which concerns on embodiment. It is a top view which shows the structure of the electrode body which concerns on the modification 1 of embodiment. It is a top view which shows the structure of the electrode body which concerns on the modification 2 of embodiment. It is a top view which shows the structure of the electrode body which concerns on the modification 3 of embodiment. It is a top view which shows the structure of the electrode body which concerns on the modification 4 of embodiment. It is a top view which shows the structure of the electrode body which concerns on the modification 5 of embodiment.

  The inventor of the present application uses the positive electrode plate or the negative electrode plate in the conventional power storage device as described in Patent Document 1 because the positive electrode plate and the negative electrode plate of the electrode body are connected to the electrode terminals. We focused on the fact that may rotate around the connection with the electrode terminal. In such a case, the inventor of the present application may shift the relative positions of the positive electrode plate and the negative electrode plate, and one electrode plate may protrude from the other electrode plate. It has been found that metal ions in the active material of the plate may be deposited, and the positive electrode plate and the negative electrode plate may be short-circuited.

  In order to solve this problem, a power storage device according to one embodiment of the present invention is a power storage device including an electrode body in which a positive electrode plate and a negative electrode plate are stacked, and an electrode terminal connected to the electrode body, At least one of the positive electrode plate and the negative electrode plate has a main body portion and a connection portion extending in a first direction from one end portion of the main body portion and connected to the electrode terminal. In the range where the positive electrode plate and the negative electrode plate in one direction overlap, the difference in width between the negative electrode plate and the positive electrode plate in the second direction orthogonal to the first direction is the difference between the one end and the other end. The other end portion is formed larger than the intermediate portion therebetween.

  According to this, in the power storage element, at least one of the positive electrode plate and the negative electrode plate of the electrode body is connected to the electrode terminal at the connection portion on one end side of the main body portion, and rotates around the connection portion. There is a risk. For this reason, in the main body of the electrode plate, by forming the width difference between the positive electrode plate and the negative electrode plate larger at the other end than the intermediate part, even when the electrode plate rotates around the connection part, It can suppress that the other end part of a main-body part protrudes from the other electrode plate. This can reduce the possibility that the positive electrode plate and the negative electrode plate of the electrode body are short-circuited even when the power storage element is used abnormally.

  The main body portion may be a main body portion of the positive electrode plate, and the main body portion may be formed such that a width in the second direction is smaller at the other end portion than at the intermediate portion. .

  According to this, in the electric storage element, the width of the main body portion of the positive electrode plate of the electrode body is formed to be smaller at the other end portion than at the intermediate portion, so that the negative electrode plate and the positive electrode plate on the other end side The difference in width can be increased. For this reason, even when the positive electrode plate rotates around the connecting portion, the positive electrode plate can be prevented from protruding from the negative electrode plate. Can reduce the risk of short circuiting.

  Further, the main body portion is a main body portion of the positive electrode plate, and the negative electrode plate has a width in the second direction corresponding to the other end portion of the main body portion rather than a portion corresponding to an intermediate portion of the main body portion. The part to be formed may be formed larger.

  According to this, in the electric storage element, the width of the negative electrode plate of the electrode body is formed larger on the other end side than on the intermediate portion side of the positive electrode plate, so that the negative electrode plate and the positive electrode on the other end side are formed. The difference in width with the plate can be increased. For this reason, even when the positive electrode plate rotates around the connecting portion, the positive electrode plate can be prevented from protruding from the negative electrode plate. Can reduce the risk of short circuiting.

  The main body portion may be a main body portion of the negative electrode plate, and the main body portion may have a width in the second direction that is larger at the other end portion than at the intermediate portion. .

  According to this, in the electric storage element, the width of the main body part of the negative electrode plate of the electrode body is formed larger at the other end part than at the intermediate part, so that the negative electrode plate and the positive electrode plate on the other end side The difference in width can be increased. For this reason, even when the negative electrode plate rotates around the connection portion, the positive electrode plate can be prevented from protruding from the negative electrode plate, and even when used abnormally, the positive electrode plate and the negative electrode plate of the electrode body Can reduce the risk of short circuiting.

  Further, the main body portion is a main body portion of the negative electrode plate, and the positive electrode plate has a width in the second direction corresponding to the other end portion of the main body portion rather than a portion corresponding to an intermediate portion of the main body portion. The portion to be formed may be formed smaller.

  According to this, in the electric storage element, the width of the positive electrode plate of the electrode body is formed smaller on the other end side than the intermediate side of the negative electrode plate, so that the negative electrode plate and the positive electrode on the other end side are formed. The difference in width with the plate can be increased. For this reason, even when the negative electrode plate rotates around the connection portion, the positive electrode plate can be prevented from protruding from the negative electrode plate, and even when used abnormally, the positive electrode plate and the negative electrode plate of the electrode body Can reduce the risk of short circuiting.

  The electrode body further includes a separator disposed between the positive electrode plate and the negative electrode plate, and the separator has a width in the second direction corresponding to an intermediate portion of the main body portion. The part corresponding to the other end part of the main body part may be formed larger than that.

  According to this, in the electricity storage element, the width of the separator of the electrode body is formed larger on the other end side than on the intermediate side, corresponding to the shape of the negative electrode plate. For this reason, the separator does not have a shape that is larger than necessary to insulate the positive electrode plate from the negative electrode plate. It is possible to suppress the reduction.

  Further, the intermediate portion may be formed such that a difference in width between the negative electrode plate and the positive electrode plate in the second direction is uniformly formed.

  According to this, in the electric storage element, positioning at the time of arranging the positive electrode plate and the negative electrode plate can be easily performed by the intermediate portion where the difference in width between the negative electrode plate and the positive electrode plate of the electrode body is uniform.

  Hereinafter, a power storage device according to an embodiment of the present invention and a modification thereof will be described with reference to the drawings. It should be noted that each of the embodiments and modifications thereof described below is a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, and the like shown in the following embodiments and modifications thereof are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments and modifications thereof, constituent elements that are not described in the independent claims indicating the highest concept are described as arbitrary constituent elements. In each drawing, dimensions and the like are not strictly illustrated.

  In the following description and drawings, the opposing direction of the long side of the container, the short side of the short side of the container, the thickness direction of the container, or the stacking direction of the electrode plates of the electrode body is defined as the X-axis direction. . In addition, the arrangement direction of the pair of current collectors, the arrangement direction of the pair of electrode terminals, the arrangement direction of the tab group of the pair of electrode bodies, the short direction of the electrode bodies, or the opposing direction of the short side surface of the container Is defined as the Y-axis direction (or the second direction). In addition, the vertical direction of the electricity storage element (the direction in which gravity acts when the container lid is placed upward), the longitudinal direction of the electrode body, the longitudinal direction of the long side surface of the container, or the longitudinal direction of the short side surface of the container The direction is defined as the Z-axis direction (or the first direction). These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in this embodiment). Although the case where the Z-axis direction does not become the vertical direction may be considered depending on the usage mode, the Z-axis direction will be described below as the vertical direction for convenience of explanation. In the following description, for example, the X axis direction plus side indicates the arrow direction side of the X axis, and the X axis direction minus side indicates the opposite side to the X axis direction plus side. The same applies to the Y-axis direction and the Z-axis direction.

(Embodiment)
First, a general description of the power storage element 10 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing an external appearance of a power storage element 10 according to the present embodiment. FIG. 2 is an exploded perspective view showing each component by disassembling the power storage device 10 according to the present embodiment. Moreover, FIG. 3 is sectional drawing which shows the internal structure of the electrical storage element 10 which concerns on this Embodiment. 3 is a cross-sectional view showing a configuration around the positive electrode terminal 210 when the power storage device 10 shown in FIG. 1 is cut along a plane parallel to the XZ plane including the line III-III.

  The storage element 10 is a secondary battery that can charge electricity and discharge electricity, and specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is used, for example, for an automobile power source such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), an electronic device power source, and a power storage power source. The storage element 10 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, a capacitor, or a primary battery. May be.

  As shown in FIG. 1, the electricity storage device 10 includes a container 100, a positive electrode terminal 210, a negative electrode terminal 220, a positive electrode upper gasket 310, and a negative electrode upper gasket 320. As shown in FIG. 2, a positive electrode lower gasket 410, a negative electrode lower gasket 420, a positive electrode current collector 510, a negative electrode current collector 520, and an electrode body 600 are accommodated inside the container 100. Moreover, although the electrolyte solution (nonaqueous electrolyte) is enclosed in the inside of the container 100, illustration is abbreviate | omitted. In addition, as long as the electrolyte solution enclosed with the container 100 does not impair the performance of the electrical storage element 10, there is no restriction | limiting in particular in the kind, Various things can be selected.

  The container 100 includes a container body 110 having a rectangular cylindrical shape and a bottom, and a lid body 120 that is a plate-like member that closes the opening of the container body 110. In addition, the container 100 can be hermetically sealed by welding the lid body 120 and the container body 110 after the electrode body 600 and the like are accommodated therein. The container 100 is made of a weldable metal such as stainless steel, aluminum, or aluminum alloy. The lid 120 is provided with a liquid injection part for injecting an electrolyte into the container 100 and a gas discharge valve for discharging the gas inside the container 100 when the internal pressure of the container 100 rises. Detailed description thereof will be omitted.

  The positive electrode terminal 210 is an electrode terminal electrically connected to the positive electrode plate of the electrode body 600 through the positive electrode current collector 510. The negative electrode terminal 220 is an electrode terminal electrically connected to the negative electrode plate of the electrode body 600 through the negative electrode current collector 520. That is, the positive electrode terminal 210 and the negative electrode terminal 220 lead the electricity stored in the electrode body 600 to the external space of the power storage element 10, and in order to store the electricity in the electrode body 600, It is an electrode terminal made of metal for introducing. As shown in FIG. 3, the positive electrode terminal 210 and the negative electrode terminal 220 are connected to the positive electrode current collector 510 and the negative electrode current collector 520 by caulking or the like. Note that the positive electrode terminal 210 and the negative electrode terminal 220 are formed of aluminum or an aluminum alloy.

  The electrode body 600 is a power storage element (power generation element) that includes a positive electrode plate, a negative electrode plate, and a separator and can store electricity. Specifically, the electrode body 600 is formed in a layered manner so that a separator is sandwiched between a positive electrode plate and a negative electrode plate. Thereby, in the electrode body 600, the tab 612 of the positive electrode plate is laminated, and the tab 622 of the negative electrode plate is laminated. A detailed description of the configuration of the electrode body 600 will be described later.

  The positive electrode current collector 510 and the negative electrode current collector 520 are disposed between the electrode body 600 and the lid body 120 of the container 100 and electrically connect the electrode body 600 to the positive electrode terminal 210 and the negative electrode terminal 220. It is a U-shaped plate-shaped member. As shown in FIG. 3, the positive electrode current collector 510 is joined to a plurality of tabs 612 stacked on the positive electrode side of the electrode body 600 by welding or the like, and the negative electrode current collector 520 is stacked on the negative electrode side of the electrode body 600. The plurality of tabs 622 are joined by welding or the like. Note that the positive electrode current collector 510 is formed of aluminum or an aluminum alloy, and the negative electrode current collector 520 is formed of copper or a copper alloy.

  The positive upper gasket 310 and the negative upper gasket 320 are insulating sealing members that are disposed between the lid 120 of the container 100 and the positive terminal 210 and the negative terminal 220. The positive electrode upper gasket 310 and the negative electrode upper gasket 320 are formed so as to cover lower portions and side portions of the positive electrode terminal 210 and the negative electrode terminal 220, respectively. The positive electrode lower gasket 410 and the negative electrode lower gasket 420 are flat insulating insulating members disposed between the lid 120 and the positive electrode current collector 510 and the negative electrode current collector 520. These gaskets are made of, for example, polycarbonate (PC), polypropylene (PP), polyethylene (PE), or polyphenylene sulfide resin (PPS).

  Next, the configuration of the electrode body 600 will be described in detail. FIG. 4 is a plan view showing the configuration of the electrode body 600 according to the present embodiment. Specifically, this figure is a view of the electrode body 600 shown in FIG. 2 as seen from the X axis direction plus side.

  As shown in FIG. 4, the electrode body 600 includes a positive electrode plate 610, a negative electrode plate 620, and a separator 630, and is formed by alternately laminating them. That is, the electrode body 600 is formed by arranging the separator 630 between the positive electrode plate 610 and the negative electrode plate 620 when the positive electrode plates 610 and the negative electrode plates 620 are alternately arranged. Further, the negative electrode plate 620 is larger than the positive electrode plate 610, and the separator 630 is larger than the negative electrode plate 620.

  The positive electrode plate 610 is an electrode plate in which a positive electrode active material layer is formed on the surface of a positive electrode base material layer that is a flat current collector foil made of aluminum or an aluminum alloy. The negative electrode plate 620 is an electrode plate in which a negative electrode active material layer is formed on the surface of a negative electrode base material layer that is a flat current collector foil made of copper or a copper alloy. Note that as the current collector foil, a known material such as nickel, iron, stainless steel, titanium, baked carbon, a conductive polymer, conductive glass, or an Al—Cd alloy can be used as appropriate. The separator 630 is a microporous sheet made of, for example, a resin. In addition, as a raw material of the separator 630, if it does not impair the performance of the electrical storage element 10, such as a nonwoven fabric, a well-known material can be used suitably.

Moreover, as a positive electrode active material used for a positive electrode active material layer, if it is a positive electrode active material which can occlude-release lithium ion, a well-known material can be used suitably. For example, as a positive electrode active material, a polyanion compound such as LiMPO ₄ , LiMSiO ₄ , LiMBO ₃ (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), lithium titanate, Spinel type lithium manganese oxide such as LiMn ₂ O ₄ and LiMn _1.5 Ni _0.5 O ₄ , LiMO ₂ (M is one or more transition metals selected from Fe, Ni, Mn, Co, etc.) Lithium transition metal oxides such as (element) can be used.

Moreover, as a negative electrode active material used for a negative electrode active material layer, if it is a negative electrode active material which can occlude-release lithium ion, a well-known material can be used suitably. For example, as the negative electrode active material, lithium metal, lithium alloy (lithium metal-containing alloys such as lithium-silicon, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and wood alloy) Other alloys that can occlude and release lithium, carbon materials (eg, graphite, non-graphitizable carbon, graphitizable carbon, low-temperature calcined carbon, amorphous carbon, etc.), silicon oxide, metal oxide, lithium metal oxide (Li ₄ Ti ₅ O ₁₂ etc.), polyphosphoric acid compounds, compounds of transition metals and group 14 to group 16 elements such as Co ₃ O ₄ and Fe ₂ P, generally called conversion anodes, etc. It is done.

  Here, the positive electrode plate 610 includes a main body 611 and a tab 612. The main body 611 is a substantially rectangular portion where the positive electrode active material layer of the positive electrode plate 610 is formed. Here, the end on the positive side in the Z-axis direction of the main body 611 is defined as one end 611a, the end on the negative in the Z-axis direction is defined as the other end 611b, and a portion between the one end 611a and the other end 611b is defined. Let it be an intermediate part 611c. For example, of the portion in the Z-axis direction of the main body portion 611, a portion of about 20-30% on the positive side of the Z-axis direction of the main body portion 611 is defined as one end portion 611a, and a portion of about 20-30% on the negative side of the Z-axis direction. Is the other end portion 611b, and a portion of about 40 to 60% of the intermediate position is the intermediate portion 611c. In addition, how to divide this one end part 611a, the other end part 611b, and the intermediate part 611c is not limited to the above.

  The tab 612 is a rectangular portion where the positive electrode active material layer of the positive electrode plate 610 is not formed and the positive electrode base material layer is exposed, and protrudes from the one end 611a of the main body 611 in the first direction (Z-axis direction). It extends. Specifically, the tab 612 extends from the main body portion 611 toward the positive electrode terminal 210, the positive electrode upper gasket 310, the positive electrode lower gasket 410, the positive electrode current collector 510, or the lid body 120 of the container 100 (Z-axis direction plus). Side).

  Similarly, the negative electrode plate 620 includes a main body portion 621 and a tab 622. The main body 621 is a substantially rectangular portion where the negative electrode active material layer of the negative electrode plate 620 is formed. Here, the end on the plus side in the Z-axis direction of the main body 621 is set as one end 621a, the end on the minus side in the Z-axis direction is set as the other end 621b, and a portion between the one end 621a and the other end 621b is set. The intermediate portion 621c is assumed. For example, about 20 to 30% of the main body 621 in the Z-axis direction is about 20 to 30% on the positive side in the Z-axis direction of the main body 621, and about 20 to 30% on the negative side in the Z-axis direction. Is the other end portion 621b, and a portion of about 40 to 60% of the intermediate position is the intermediate portion 621c. In addition, how to divide this one end part 621a, the other end part 621b, and the intermediate part 621c is not limited to the above.

  The tab 622 is a rectangular part where the negative electrode active material layer of the negative electrode plate 620 is not formed and the negative electrode base material layer is exposed, and protrudes from the one end 621a of the main body 621 in the first direction (Z-axis direction). It extends. Specifically, the tab 622 extends from the main body portion 621 toward the negative electrode terminal 220, the negative electrode upper gasket 320, the negative electrode lower gasket 420, the negative electrode current collector 520, or the lid body 120 of the container 100 (Z-axis direction plus). Side).

  Then, the plurality of positive plates 610 and the plurality of negative plates 620 are stacked, so that a plurality of tabs 612 are stacked and a plurality of tabs 622 are stacked. As a result, the electrode body 600 is formed with a positive-side tab group composed of a plurality of tabs 612 and a negative-electrode side tab group composed of a plurality of tabs 622. The tab group on the positive electrode side and the tab group on the negative electrode side are joined to the positive electrode current collector 510 and the negative electrode current collector 520 by welding or the like, and are electrically connected to the positive electrode terminal 210 and the negative electrode terminal 220.

  In this way, at least one of the positive electrode plate 610 and the negative electrode plate 620 (both in the present embodiment) is a main body and a connection portion that extends in the first direction from one end of the main body and is connected to the electrode terminal. And tabs.

  Further, the main body has a width difference between the negative electrode plate 620 and the positive electrode plate 610 in the second direction orthogonal to the first direction in the range where the positive electrode plate 610 and the negative electrode plate 620 in the first direction overlap. The other end is formed larger than the other end. The range in which the positive electrode plate 610 and the negative electrode plate 620 overlap in the first direction is different from one end of the portion where the main body portion 611 of the positive electrode plate 610 and the main body portion 621 of the negative electrode plate 620 overlap in the first direction. It is a range extending to the end. In the present embodiment, since the main body portion 611 of the positive electrode plate 610 is smaller than the main body portion 621 of the negative electrode plate 620, the range where the positive electrode plate 610 and the negative electrode plate 620 in the first direction overlap is the main body portion of the positive electrode plate 610. This is a range extending from one end 611a to the other end 611b of 611. The second direction is the Y-axis direction in the present embodiment. The second direction is a direction orthogonal to the first direction in the plane (in the YZ plane) in which the main body 611 of the positive electrode plate 610 and the main body 621 of the negative electrode plate 620 spread, or the main body 611 of the positive electrode plate 610 It can also be defined as a direction along the main body 621 of the negative electrode plate 620 and orthogonal to the first direction.

  Specifically, the width of the positive electrode plate 610 in the second direction is smaller at the portion corresponding to the other end portion 621b of the main body portion 621 than at the portion corresponding to the intermediate portion 621c of the main body portion 621 of the negative electrode plate 620. Is formed. That is, the main body 611 of the positive electrode plate 610 is formed such that the width in the second direction is smaller at the other end 611b than at the middle 611c. In the present embodiment, the main body 611 is formed such that the width in the second direction is smaller at the other end 611b than at the one end 611a and the intermediate portion 611c.

  More specifically, in the main body 611 of the positive electrode plate 610, the one end 611a has the same constant value as the intermediate portion 611c in the second direction, and the other end 611b extends from the intermediate portion 611c to the Y axis. Both sides in the direction are inclined linearly (changed continuously in a taper shape) to reduce the width. That is, the other end 611b has a shape in which the corner on the minus side in the Z-axis direction of the main body 611 is cut out in a triangular shape. In this manner, the other end 611b has a shape having a plurality of corners. However, in order to prevent the separator 630 or the negative electrode plate 620 from being damaged, the plurality of corners are rounded to become an R portion. ing. Further, in the main body portion 621 of the negative electrode plate 620, the width in the second direction is the same constant value in the one end portion 621a, the intermediate portion 621c, and the other end portion 621b.

  For this reason, the main body 611 of the positive electrode plate 610 has a difference in width between the negative electrode plate 620 and the positive electrode plate 610 in the second direction (a value obtained by subtracting the width of the positive electrode plate 610 from the width of the negative electrode plate 620). The other end 611b is formed larger than the intermediate portion 611c. In other words, the main body portion 621 of the negative electrode plate 620 has an end portion 621a having a difference in width between the negative electrode plate 620 and the positive electrode plate 610 in the second direction (a value obtained by subtracting the width of the positive electrode plate 610 from the width of the negative electrode plate 620). The other end portion 621b is formed larger than the intermediate portion 621c. Further, the intermediate part 611c and the intermediate part 621c are portions where the difference in width between the negative electrode plate 620 and the positive electrode plate 610 in the second direction is uniform.

  The separator 630 is disposed between one end 631a that is the end on the plus side in the Z-axis direction, the other end 631b that is the end on the minus side in the Z-axis direction, and the one end 631a and the other end 631b. Intermediate portion 631c. The separator 630 is larger than the main body portion 621 so as to cover the main body portion 621 of the negative electrode plate 620, and the one end portion 631a, the other end portion 631b, and the intermediate portion 631c are formed with constant values having the same width in the second direction. Has been. The way of dividing the one end portion 631a, the other end portion 631b, and the intermediate portion 631c is the same as the way of dividing the positive electrode plate 610 and the negative electrode plate 620.

  As described above, according to the electric storage element 10 according to the embodiment of the present invention, at least one of the positive electrode plate 610 and the negative electrode plate 620 of the electrode body 600 is an electrode terminal with a tab on one end side of the main body portion. There is a risk of rotating around the tab. When the electrode plate rotates around the tab, the positive electrode plate 610 may protrude from the negative electrode plate 620. When the positive electrode plate 610 protrudes from the negative electrode plate 620, a portion that does not face the negative electrode plate 620 is generated on the positive electrode plate 610. In this case, in the portion of the positive electrode plate 610 that does not face the negative electrode plate 620, the destination of lithium ions in the positive electrode active material of the positive electrode plate 610 disappears, and the lithium ions are deposited on the negative electrode plate 620, the container 100, and the like. This may cause a short circuit between the positive electrode plate 610 and the negative electrode plate 620.

  On the other hand, according to the electric storage element 10, in the main body portion of the electrode plate, the electrode plate is formed by forming the width difference between the positive electrode plate 610 and the negative electrode plate 620 larger at the other end portion than at the intermediate portion. Even when rotated about the tab, the other end of the main body can be prevented from protruding from the other electrode plate. This can reduce the possibility that the positive electrode plate 610 and the negative electrode plate 620 of the electrode body 600 are short-circuited even when the power storage element 10 is used abnormally.

  Specifically, in the power storage element 10, the width of the main body 611 of the positive electrode plate 610 of the electrode body 600 is formed so that the other end 611b is smaller than the intermediate 611c, so that the other end 611b side. The difference in width between the negative electrode plate 620 and the positive electrode plate 610 can be increased. Therefore, even when the positive electrode plate 610 rotates around the tab 612 (rotation A1 in FIG. 4), the positive electrode plate 610 can be prevented from protruding from the negative electrode plate 620, and even when used abnormally. The possibility that the positive electrode plate 610 and the negative electrode plate 620 of the electrode body 600 are short-circuited can be reduced.

  Moreover, in the electrical storage element 10, the width of the positive electrode plate 610 of the electrode body 600 is formed smaller on the other end 621b side than on the intermediate portion 621c side of the negative electrode plate 620, so that the other end 621b side The difference in width between the negative electrode plate 620 and the positive electrode plate 610 can be increased. Therefore, even when the negative electrode plate 620 rotates around the tab 622 (rotation B1 in FIG. 4), the positive electrode plate 610 can be prevented from protruding from the negative electrode plate 620, and even when used abnormally. The possibility that the positive electrode plate 610 and the negative electrode plate 620 of the electrode body 600 are short-circuited can be reduced.

  In addition, in the Z-axis direction, the length that one end 621a of the main body 621 of the negative electrode plate 620 protrudes from the one end 611a of the main body 611 of the positive electrode 610 and the other end 621b protrude from the other end 611b. The relationship with the length is not particularly limited. However, considering the case where the positive electrode plate 610 rotates around the tab 612 or the case where the negative electrode plate 620 rotates around the tab 622, the length of the length that the other end 621b protrudes from the other end 611b However, it is preferable that the one end 621a is longer than the length protruding from the one end 611a.

  Further, in the electric storage element 10, the intermediate plate 610c and the intermediate plate 621c having a uniform width difference between the negative electrode plate 620 and the positive electrode plate 610 of the electrode body 600 can be easily positioned when the positive electrode plate 610 and the negative electrode plate 620 are arranged. It can be carried out.

(Modification 1)
Next, Modification 1 of the above embodiment will be described. FIG. 5 is a plan view showing a configuration of an electrode body 601 according to Modification 1 of the present embodiment. Specifically, this figure corresponds to FIG.

  As shown in FIG. 5, the electrode body 601 includes a negative electrode plate 620a instead of the negative electrode plate 620 in the above embodiment. Further, the negative electrode plate 620a has a tab 622a protruding downward from the other end 621b of the main body 621 instead of the tab 622 protruding upward from the one end 621a of the main body 621 in the above embodiment. . Also in this configuration, as in the above embodiment, the main body 611 of the positive electrode plate 610 has a width in the second direction (Y-axis direction) that is smaller at the other end 611b than at the one end 611a and the middle 611c. Is formed.

  As described above, according to the electricity storage device according to the present modification, the width of the main body 611 of the positive electrode plate 610 of the electrode body 601 is greater at the other end 611b than at the middle 611c, as in the above embodiment. Is made small, the difference in width between the negative electrode plate 620a and the positive electrode plate 610 on the other end 611b side can be increased. For this reason, even when the positive electrode plate 610 rotates around the tab 612 (rotation A1 in FIG. 5), the positive electrode plate 610 can be prevented from protruding from the negative electrode plate 620a, and even when used abnormally. The possibility that the positive electrode plate 610 and the negative electrode plate 620a of the electrode body 601 are short-circuited can be reduced.

  In this modification, one end 611a of the positive electrode plate 610 may have the same shape as the other end 611b. That is, the main body 611 of the positive electrode plate 610 may be formed such that the width in the second direction (Y-axis direction) is smaller at the one end 611a than at the intermediate 611c. Accordingly, even when the negative electrode plate 620a rotates around the tab 622a, the positive electrode plate 610 can be prevented from protruding from the negative electrode plate 620a, and the positive electrode plate of the electrode body 601 can be used even when used abnormally. The possibility that 610 and the negative electrode plate 620a are short-circuited can be reduced.

(Modification 2)
Next, a second modification of the above embodiment will be described. FIG. 6 is a plan view showing a configuration of an electrode body 602 according to the second modification of the present embodiment. Specifically, this figure corresponds to FIG.

  As shown in FIG. 6, the electrode body 602 includes a positive electrode plate 610a instead of the positive electrode plate 610 in the above embodiment. Further, the positive electrode plate 610a has a tab 612a protruding downward from the other end 611b of the main body 611 instead of the tab 612 protruding upward from the one end 611a of the main body 611 in the above embodiment. . Also in this configuration, as in the above embodiment, the positive electrode plate 610a has a width in the second direction (Y-axis direction) from a portion corresponding to the one end 621a and the intermediate portion 621c of the main body 621 of the negative electrode 620. Also, the portion corresponding to the other end 621b of the main body 621 is formed smaller.

  As described above, according to the power storage device according to this modification, the width of the positive electrode plate 610a of the electrode body 602 is closer to the other end 621b side than the intermediate portion 621c side of the negative electrode plate 620, as in the above embodiment. By forming the smaller one, the difference in width between the negative electrode plate 620 and the positive electrode plate 610a on the other end 621b side can be increased. For this reason, even when the negative electrode plate 620 rotates around the tab 622 (rotation B1 in FIG. 6), the positive electrode plate 610a can be prevented from protruding from the negative electrode plate 620, and even when used abnormally. The possibility that the positive electrode plate 610a and the negative electrode plate 620 of the electrode body 602 are short-circuited can be reduced.

  In this modification, one end 611a of the positive electrode plate 610a may have the same shape as the other end 611b. That is, the main body 611 of the positive electrode plate 610a may be formed so that the width in the second direction (Y-axis direction) is smaller at the one end 611a than at the intermediate 611c. Thereby, even when the positive electrode plate 610a rotates around the tab 612a, the positive electrode plate 610a can be prevented from protruding from the negative electrode plate 620, and the positive electrode plate of the electrode body 602 can be used even when used abnormally. The risk of short-circuiting between 610a and the negative electrode plate 620 can be reduced.

(Modification 3)
Next, Modification 3 of the above embodiment will be described. FIG. 7 is a plan view showing a configuration of an electrode body 603 according to the third modification of the present embodiment. Specifically, this figure corresponds to FIG.

  As shown in FIG. 7, the electrode body 603 includes a positive electrode plate 610b, a negative electrode plate 620b, and a separator 630a instead of the positive electrode plate 610, the negative electrode plate 620, and the separator 630 in the above embodiment. Further, the positive plate 610b, the negative plate 620b, and the separator 630a are replaced with the other end 611d, the other end 621d, and the other end instead of the other end 611b, the other end 621b, and the other end 631b in the above embodiment. 631d.

  The other end portion 611d of the positive electrode plate 610b has a width in the second direction (Y-axis direction) that is the same constant value as the one end portion 611a and the intermediate portion 611c. Further, the negative electrode plate 620b has a width in the second direction (Y-axis direction) that corresponds to the other end 611d of the main body 611 rather than a portion corresponding to the one end 611a and the middle 611c of the main body 611 of the positive electrode 610b. The part to be formed is formed larger. That is, the main body 621 of the negative electrode plate 620b is formed such that the width in the second direction is larger at the other end 621d than at the one end 621a and the intermediate portion 621c.

  Specifically, the other end portion 621d of the negative electrode plate 620b is linearly inclined on both sides in the Y-axis direction from the intermediate portion 621c and has a large width. That is, the other end 621d has a shape in which the corner on the negative side in the Z-axis direction of the main body 621 is projected in a substantially rectangular shape on both sides in the Y-axis direction. Thus, although the other end 621d has a shape having a plurality of corners, the plurality of corners are rounded to form an R portion in order to prevent the separator 630a from being damaged.

  The width of the separator 630a in the second direction is larger than that of the main body portion 611 and the main body portion 621, and the main body portion 611 and the main body portion 621 than the portions corresponding to the one end portion 611a, the intermediate portion 611c and the one end portion 621a, The portions corresponding to the other end 611d and the other end 621d are formed larger. That is, the separator 630a is formed such that the width in the second direction is larger at the other end 631d than at the one end 631a and the intermediate portion 631c. Specifically, the width of the other end 631d of the separator 630a is increased by linearly inclining on both sides in the Y-axis direction from the intermediate portion 631c. That is, the other end 631d has a shape in which the corner on the negative side in the Z-axis direction of the separator 630a is projected in a substantially rectangular shape on both sides in the Y-axis direction.

  As described above, according to the electricity storage device according to this modification, the width of the negative electrode plate 620b of the electrode body 603 is formed larger on the other end 611d side than on the intermediate portion 611c side of the positive electrode plate 610b. Thus, the difference in width between the negative electrode plate 620b and the positive electrode plate 610b on the other end 611d side can be increased. For this reason, even when the positive electrode plate 610b rotates around the tab 612 (rotation A2 in FIG. 7), the positive electrode plate 610b can be prevented from protruding from the negative electrode plate 620b, and even when used abnormally. The possibility that the positive electrode plate 610b and the negative electrode plate 620b of the electrode body 603 are short-circuited can be reduced.

  Further, the width of the main body portion 621 of the negative electrode plate 620b of the electrode body 603 is formed so that the other end portion 621d is larger than the intermediate portion 621c, so that the negative electrode plate 620b and the positive electrode plate 610b on the other end portion 621d side. And the width difference can be increased. For this reason, even when the negative electrode plate 620b rotates around the tab 622 (rotation B2 in FIG. 7), the positive electrode plate 610b can be prevented from protruding from the negative electrode plate 620b, and even when used abnormally. The possibility that the positive electrode plate 610b and the negative electrode plate 620b of the electrode body 603 are short-circuited can be reduced.

  In addition, the width of the separator 630a of the electrode body 603 is formed to be larger on the other end 631d side than on the intermediate part 631c side, corresponding to the shape of the negative electrode plate 620b. For this reason, the separator 630a does not have a shape that is larger than necessary to insulate the positive electrode plate 610b and the negative electrode plate 620b, which may hinder gas discharge when the gas discharge valve is opened, or may be injected when electrolyte is injected. It can suppress that liquidity falls.

  In this modification, the other end 611d of the positive electrode plate 610b may have the same shape as the other end 611b of the above embodiment.

(Modification 4)
Next, Modification 4 of the above embodiment will be described. FIG. 8 is a plan view showing a configuration of an electrode body 604 according to Modification 4 of the present embodiment. Specifically, this figure corresponds to FIG.

  As shown in FIG. 8, the electrode body 604 includes a negative electrode plate 620c instead of the negative electrode plate 620b in the third modification. Further, the negative electrode plate 620c has a tab 622a protruding downward from the other end 621d of the main body 621 instead of the tab 622 protruding upward from the one end 621a of the main body 621 in the third modification. . Also in this configuration, as in the third modification, the negative electrode plate 620c has a width in the second direction (Y-axis direction) from a portion corresponding to the one end 611a and the intermediate portion 611c of the main body 611 of the positive electrode 610b. Also, the portion corresponding to the other end 611d of the main body 611 is formed larger.

  As described above, according to the electricity storage device according to this modification, as in Modification 3, the width of the negative electrode plate 620c of the electrode body 604 is closer to the other end 611d side than the intermediate portion 611c side of the positive electrode plate 610b. By forming the larger one, the difference in width between the negative electrode plate 620c and the positive electrode plate 610b on the other end 611d side can be increased. For this reason, even when the positive electrode plate 610b rotates around the tab 612 (rotation A2 in FIG. 8), the positive electrode plate 610b can be prevented from protruding from the negative electrode plate 620c, and even when used abnormally. The possibility that the positive electrode plate 610b and the negative electrode plate 620c of the electrode body 604 are short-circuited can be reduced.

  In the present modification, one end 621a of the negative electrode plate 620c may have the same shape as the other end 621d. That is, the main body portion 621 of the negative electrode plate 620c may be formed such that the width in the second direction (Y-axis direction) is larger at the one end portion 621a than at the intermediate portion 621c. Alternatively, the one end 611a of the positive electrode plate 610b may have the same shape as the other end 611b of the above embodiment. Accordingly, even when the negative electrode plate 620c rotates around the tab 622a, the positive electrode plate 610b can be prevented from protruding from the negative electrode plate 620c, and the positive electrode plate of the electrode body 604 can be used even when used abnormally. The possibility that 610b and the negative electrode plate 620c are short-circuited can be reduced. Further, the other end 611d of the positive electrode plate 610b may have the same shape as the other end 611b of the above embodiment.

(Modification 5)
Next, Modification 5 of the above embodiment will be described. FIG. 9 is a plan view showing a configuration of an electrode body 605 according to the fifth modification of the present embodiment. Specifically, this figure corresponds to FIG.

  As shown in FIG. 9, the electrode body 605 includes a positive electrode plate 610 c instead of the positive electrode plate 610 b in the third modification. Further, the positive electrode plate 610c has a tab 612a protruding downward from the other end 611d of the main body 611 instead of the tab 612 protruding upward from the one end 611a of the main body 611 in the third modification. . Also in this configuration, as in the third modification, the main body 621 of the negative electrode plate 620b has a width in the second direction (Y-axis direction) that is larger at the other end 621d than at the one end 621a and the middle 621c. Is formed.

  As described above, according to the electricity storage device according to this modification, as in Modification 3, the width of the main body 621 of the negative electrode plate 620b of the electrode body 605 is greater in the other end 621d than in the intermediate 621c. As a result, the difference in width between the negative electrode plate 620b and the positive electrode plate 610c on the other end 621d side can be increased. For this reason, even when the negative electrode plate 620b rotates around the tab 622 (rotation B2 in FIG. 9), the positive electrode plate 610c can be prevented from protruding from the negative electrode plate 620b, and even when used abnormally. The possibility that the positive electrode plate 610c and the negative electrode plate 620b of the electrode body 605 are short-circuited can be reduced.

  In this modification, one end 621a of the negative electrode plate 620b may have the same shape as the other end 621d. That is, the main body portion 621 of the negative electrode plate 620b may be formed so that the width in the second direction (Y-axis direction) is larger at the one end portion 621a than at the intermediate portion 621c. Alternatively, the one end 611a of the positive electrode plate 610c may have the same shape as the other end 611b of the above embodiment. Thus, even when the positive electrode plate 610c rotates around the tab 612a, the positive electrode plate 610c can be prevented from protruding from the negative electrode plate 620b, and the positive electrode plate of the electrode body 605 can be used even when used abnormally. The possibility that 610c and the negative electrode plate 620b are short-circuited can be reduced. Further, the other end 611d of the positive electrode plate 610c may have the same shape as the other end 611b of the above embodiment.

  The power storage device according to the embodiment of the present invention and the modification thereof has been described above, but the present invention is not limited to this embodiment and the modification thereof. In other words, it should be considered that the embodiment and its modification disclosed this time are illustrative and not restrictive in all respects. 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 embodiment and the modification thereof, the positive electrode plate and the negative electrode plate tabs of the electrode body are connected to the positive electrode current collector 510 and the negative electrode current collector 520, so that the positive electrode terminal 210 and the negative electrode terminal 220 It was decided to be connected. However, the positive electrode and negative electrode tabs of the electrode body may be directly connected to the positive electrode terminal 210 and the negative electrode terminal 220 without passing through the positive electrode current collector 510 and the negative electrode current collector 520.

  Further, in the above embodiment and its modification, the electrode body is such that the main body portion of the negative electrode plate is larger than the main body portion of the positive electrode plate, but the main body portion of the positive electrode plate is the main body portion of the negative electrode plate. A larger configuration may be used. In this case, the difference in width between the negative electrode plate and the positive electrode plate is a value obtained by subtracting the width of the negative electrode plate from the width of the positive electrode plate.

  Further, in the above embodiment and its modification, the positive electrode plate and the negative electrode plate body of the electrode body are substantially rectangular portions, and the difference in width between the negative electrode plate and the positive electrode plate is the other end than the one end. The part was formed to be larger. However, the shape of the main body portion of the positive electrode plate and the negative electrode plate is not particularly limited. For example, it is a polygonal shape other than a rectangular shape, a circular shape, an oval shape, an elliptical shape, etc., and the width between the negative electrode plate and the positive electrode plate The difference may be a structure in which the other end is formed larger than the one end.

  Moreover, in the said embodiment and its modification, although the active material layer was formed in the main-body part of the positive electrode plate and negative electrode plate of an electrode body, the active material layer was formed in all the said main-body parts. The active material layer may be formed at least partially.

  Moreover, in the said embodiment and its modification, suppose that the positive electrode plate and negative electrode plate of an electrode body have a rectangular tab as a connection part connected with an electrode terminal. However, the shape of the tab is not particularly limited, and may be any shape such as a polygonal shape other than a rectangular shape, a semicircular shape, a semi-oval shape, or a semi-elliptical shape. In addition, the positive electrode plate and the negative electrode plate may have the entire end portion of the electrode plate as the connection portion instead of the protruding tab.

  In the above-mentioned embodiment and its modifications 1 and 2, in the main body portion 611 of the positive electrode plate, the other end portion 611b has a shape in which both sides in the Y-axis direction are linearly inclined from the intermediate portion 611c. It was. However, the other end portion 611b may have a shape in which both sides in the Y-axis direction are inclined in a curved shape or recessed in a step shape from the intermediate portion 611c toward the minus side in the Z-axis direction and the width is reduced. Note that an inclined shape is more preferable than a recessed shape because a decrease in capacity of the power storage element can be suppressed. Moreover, it is preferable that the corner | angular part which the other end part 611b has is rounded into the R part similarly to the said embodiment. Further, the intermediate portion 611c may also have a shape whose width decreases toward the minus side in the Z-axis direction.

  Further, in the above-described modified examples 3 to 5, in the main body 621 of the negative electrode plate, the other end 621d has a shape in which both sides in the Y-axis direction are linearly inclined from the intermediate portion 621c. However, the other end portion 621d may have a shape in which both sides in the Y-axis direction protrude in a curved shape or a step shape from the intermediate portion 621c toward the negative side in the Z-axis direction and the width increases. The intermediate portion 621c may also have a shape that increases in width toward the negative side in the Z-axis direction. The same applies to the separator 630a.

  In the above-described embodiment and its modification, the positive electrode plate intermediate portion 611c and the negative electrode plate intermediate portion 621c have a difference in width in the second direction between the one end portion 611a of the positive electrode plate and the one end portion 621a of the negative electrode plate. It was decided that the difference in width was the same. However, the intermediate portion 611c of the positive electrode plate and the intermediate portion 621c of the negative electrode plate have a width difference in the second direction smaller or larger than a difference in width between the one end portion 611a of the positive electrode plate and the one end portion 621a of the negative electrode plate. It may be formed as follows.

  In the above-described embodiment and its modification, the intermediate portion 611c of the positive electrode plate and the intermediate portion 621c of the negative electrode plate are portions where the difference in width between the negative electrode plate and the positive electrode plate in the second direction is uniform. . However, the intermediate part 611c and the intermediate part 621c are not limited to the above. For example, the intermediate part 611c and the intermediate part 621c are formed so that the difference in width between the negative electrode plate and the positive electrode plate in the second direction increases toward the negative side in the Z-axis direction. It may be.

  Moreover, in the said embodiment and its modification, the separator was formed larger than the main-body part of a negative electrode plate corresponding to the shape of the main-body part of a negative electrode plate. However, the separator may be formed larger than the main body portion of the negative electrode plate without corresponding to the shape of the main body portion of the negative electrode plate. Alternatively, the separator may be formed larger than the main body portion of the positive electrode plate and smaller than the main body portion of the negative electrode plate. In this case, the separator may be formed to be slightly larger corresponding to the shape of the main body portion of the positive electrode plate, or may be formed larger without corresponding to the shape of the main body portion of the positive electrode plate.

  In addition, the form constructed | assembled combining the said embodiment and the said modification arbitrarily is also contained in the scope of the present invention.

  In addition, the present invention can be realized not only as such a power storage element, but also as an electrode body (positive electrode plate or negative electrode plate) included in the power storage element.

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

DESCRIPTION OF SYMBOLS 10 Electrical storage element 210 Positive electrode terminal 220 Negative electrode terminal 600, 601, 602, 603, 604, 605 Electrode body 610, 610a, 610b, 610c Positive electrode plate 611, 621 Main body part 611a, 621a, 631a One end part 611b, 611d, 621b, 621d , 631b, 631d Other end 611c, 621c, 631c Intermediate part 612, 612a, 622, 622a Tab (connection part)
620, 620a, 620b, 620c Negative electrode plate 630, 630a Separator

Claims (7)

An electrical storage element comprising an electrode body in which a positive electrode plate and a negative electrode plate are laminated, and an electrode terminal connected to the electrode body,
At least one of the positive electrode plate and the negative electrode plate has a main body portion, and a connection portion that extends in a first direction from one end portion of the main body portion and is connected to the electrode terminal,
The main body has a width difference between the negative electrode plate and the positive electrode plate in a second direction orthogonal to the first direction within a range in which the positive electrode plate and the negative electrode plate in the first direction overlap. The said other end part is formed larger than the intermediate part between a part and the other end part. The main body is a main body of the positive electrode plate,
The power storage device according to claim 1, wherein the main body portion is formed such that a width in the second direction is smaller at the other end portion than at the intermediate portion. The main body is a main body of the positive electrode plate,
The width of the negative electrode plate in the second direction is formed so that a portion corresponding to the other end portion of the main body portion is larger than a portion corresponding to the intermediate portion of the main body portion. Power storage element. The main body is a main body of the negative electrode plate,
The power storage device according to claim 1, wherein the main body portion is formed such that a width in the second direction is larger at the other end portion than at the intermediate portion. The main body is a main body of the negative electrode plate,
The width of the positive electrode plate in the second direction is formed so that a portion corresponding to the other end portion of the main body portion is smaller than a portion corresponding to an intermediate portion of the main body portion. Power storage element. The electrode body further includes a separator disposed between the positive electrode plate and the negative electrode plate,
5. The power separator according to claim 3, wherein the separator has a width in the second direction that is larger at a portion corresponding to the other end portion of the main body portion than at a portion corresponding to an intermediate portion of the main body portion. element. The power storage device according to any one of claims 1 to 6, wherein the intermediate portion is formed with a uniform difference in width between the negative electrode plate and the positive electrode plate in the second direction.

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