JP6102058B2 - Electricity storage element - Google Patents

Description

  The present invention relates to a power storage device having a spacer disposed between a container and an electrode body.

  Conventionally, a secondary battery in which a spacer is arranged in a space between a container and an electrode group (hereinafter referred to as “electrode body”) built in the container has been disclosed (see Patent Document 1). In the secondary battery of Patent Document 1, the spacer is shaped along the curved surface of the electrode body, thereby minimizing the space into which the electrolyte is injected and preventing the electrolyte from being wasted. Moreover, it is thought that it is an effective shape also from a viewpoint of preventing an electrode body from vibrating inside a container.

JP 2006-40899 A

  However, in the spacer as in Patent Document 1, since the shape is along the curved surface of the electrode body in all regions in the winding axis direction of the electrode body, the storage element such as the secondary battery repeatedly charges and discharges. The problem of not being able to tolerate the expansion that occurs can arise. As the electrode body expands as described above, the electrode body is pressed from the container, so that the separator constituting the electrode body is crushed, the internal resistance of the battery is increased, and the battery performance is lowered.

  Therefore, the present invention has been made in view of such a situation, and in an electricity storage device including a spacer between the container and the electrode body, the electrode body is prevented from vibrating inside the container, and the electrode It is an object of the present invention to provide a power storage element including a spacer that does not cause a decrease in performance of the power storage element due to expansion of the body.

  In order to achieve the above object, a power storage device according to one embodiment of the present invention includes an electrode body in which a positive electrode and a negative electrode coated with an active material on a surface, and a separator are stacked, and a container that houses the electrode body And a spacer disposed between the electrode body and the container, and the electrode body includes a coating region in which an active material is coated on surfaces of the positive electrode and the negative electrode, and the positive electrode and The surface of the negative electrode has an uncoated region where no active material is coated, and the spacer includes a first portion facing the uncoated region and a second portion facing the coated region. And the thickness of the first portion is greater than the thickness of the second portion.

  According to this, the thickness of the 2nd part of the spacer of the position facing the coating area | region which is areas other than the uncoated area | region of an electrode body is thinner than the thickness of a 1st part. Generally, the performance as an electrical storage element falls by the application area | region being overstressed. On the other hand, the uncoated region is a region that is unlikely to cause a decrease in performance of the power storage element even when pressed. And a coating area | region is an area | region which is easy to swell by repeating charging / discharging, and is an area | region where the performance of an electrical storage element will fall easily when it is overstressed. For this reason, by making the thickness of the second part of the spacer thinner than the thickness of the first part, it is possible to provide a space that can allow the electrode body to bulge, and even if the electrode body expands, the performance of the electricity storage device is degraded. Can be prevented.

  Further, in this power storage element, since the thickness of the first portion of the spacer facing the uncoated region is made thicker than the second portion in order to increase the vibration resistance, the uncoated region is pressed. The vibration resistance can be improved without significantly degrading the performance.

  Preferably, the gap between the second portion of the spacer and the coated region of the electrode body is larger than the gap between the first portion of the spacer and the uncoated region of the electrode body. .

  According to this, the spacer is formed so that the clearance (clearance) from the position facing the coating region of the electrode body is larger than the clearance from the position facing the uncoated region of the electrode body. . For this reason, even if the coating area expands due to repeated charging and discharging, the clearance of the position facing the coating area is large, so that the coating area of the electrode body can be allowed to expand. In addition, since the electrode body has a small clearance in an uncoated region in which the performance degradation of the electricity storage element is unlikely to occur due to the pressure, the vibration resistance can be improved in a state that does not cause the performance degradation of the electricity storage device. .

  Preferably, in the spacer, the shape of the first portion on the electrode body side is a shape along the outer surface of the electrode body.

  According to this, since the shape of the first portion of the spacer on the electrode body 120 side is a shape along the electrode body, the gap (clearance) from the position facing the first portion can be minimized. For this reason, the spacer can further improve the vibration resistance in the first portion.

  In addition, an energy storage device according to one embodiment of the present invention includes an electrode body in which a positive electrode and a negative electrode coated with an active material on a surface, a separator, a container that accommodates the electrode body, and the electrode body. A spacer disposed between the positive electrode and the negative electrode; and an active region on the surfaces of the positive electrode and the negative electrode. An uncoated region where no substance is applied, and the spacer includes a first portion facing the uncoated region and a second portion facing the coated region, the first portion It is good also as an electrical storage element in which the compression rate of this is smaller than the compression rate of said 2nd part.

  According to this, since the compressibility of the first portion of the spacer at positions corresponding to both ends of the electrode body in the winding axis direction is smaller than the compressibility of the second portion, the second portion Can be less compressed. For this reason, the space inside the container corresponding to the position can be substantially filled with the electrode body and the spacer, and the electrode body can be prevented from vibrating inside the container. For this reason, the vibration resistance of an electrical storage element can be improved.

  Moreover, the performance as an electrical storage element falls by the application area | region being pressed too much. On the other hand, the uncoated region is a region that is unlikely to cause a decrease in performance of the power storage element even when pressed. In this electricity storage device, in order to increase the vibration resistance, the compression ratio of the first portion of the spacer facing the uncoated region is made smaller than the compression rate of the second portion to press the uncoated region, Vibration resistance can be improved without significantly reducing the performance of the power storage element.

  Moreover, the compression rate of the second part of the spacer at a position facing the coating region which is a region other than the uncoated region of the electrode body is larger than the compression rate of the first part. The coating region is a region that easily swells due to repeated charge and discharge, and is a region in which the performance of the electricity storage element is likely to deteriorate when excessively compressed. For this reason, when the compression ratio of the second part of the spacer is made larger than the compression ratio of the first part, when the force for pushing the second part is generated due to the expansion of the electrode body, the second part is compressed and the electrode body expands. Therefore, even if the electrode body expands, it is possible to prevent the performance of the power storage element from being deteriorated.

  Preferably, the electrode body is formed by laminating and winding the positive electrode, the negative electrode, and the separator, and the positive electrode, the negative electrode, and the separator are laminated in a plane. A flat surface portion and a curved surface portion that is laminated with a curved surface are formed, and are accommodated in the container so that the curved surface portion faces the bottom surface of the container, and the spacer includes the bottom surface of the container and the It arrange | positions between the curved-surface parts of an electrode body.

  Preferably, the spacer includes a support portion that supports the electrode body, and two sandwiching portions that are disposed at both ends of the support portion and sandwich both side surfaces of the electrode body, and the support portion and / or Or the said clamping part has a weak part.

  According to this, the spacer has a support portion that supports the electrode body, and a sandwiching portion that is disposed at both ends of the support portion and along the longitudinal direction of the support portion, and sandwiches the electrode body. A weak part is formed in the support part and / or the clamping part. Therefore, it is possible to make the support portion easy to bend so that the holding portions provided at both ends of the support portion are opened with the support portion and / or the fragile portion (or the vicinity thereof) of the holding portion as a base point. For this reason, it is possible to easily sandwich the clamping portion around the outer periphery of the electrode body formed by a curved surface, and it is possible to easily place the spacer along the electrode body. Thereby, a spacer can be easily arrange | positioned so that an electrode body may not be damaged.

  Preferably, the fragile portion is formed in the first portion of the spacer.

  According to this, a weak part is formed only in the 1st part thicker than the 2nd part of a spacer. For this reason, the 1st part of the structure which is thicker than the 2nd part and is hard to bend can be made into the structure which is easy to bend.

  Preferably, the support part further includes a thin part as the weak part whose thickness is thinner than other parts, and the thickness of the thin part is equal to the thickness of the second part.

  According to this, since the thickness of the thin portion formed in the spacer is equal to the thickness of the second portion, the support portion can be easily bent with the thin portion extending in the winding axis direction as a base point. .

  In addition, preferably, the support part has an elongated shape, and the weak part is a groove part extending along a longitudinal direction of the support part.

  According to this, a groove part is formed in the support part over the winding axis direction in the spacer. For this reason, the support part of a spacer can be made into the structure which is easy to bend on the basis of the groove part extended in the winding axis direction.

  Preferably, an insulating sheet is further provided to cover a side surface of the electrode body, and the sandwiching portion of the spacer sandwiches an end portion of the insulating sheet together with the electrode body.

  According to this, since a spacer can be covered so that it may overlap with the insulating sheet which covers the side surface of an electrode body, the insulation in the part which an insulating sheet and a spacer overlap can be improved. In addition, since the spacer overlaps the outside of the insulating sheet, the insulating sheet is disposed on the electrode body even if the electrode body is covered with the insulating sheet and inserted into the container with the spacer further covered. It can be prevented from turning up from the end of the side. For this reason, it can prevent that the electrical storage element with which the insulation of the electrode body fell is produced, and the productivity of an electrical storage element can be improved.

  Further, the positive electrode and the negative electrode coated with the active material on the surface, the electrode body on which the separator is laminated, the container for housing the electrode body, and the electrode body and the bottom surface of the container are disposed. A spacer, and the electrode body includes a coating region in which an active material is coated on the surfaces of the positive electrode and the negative electrode, and an uncoated material in which an active material is not coated on the surfaces of the positive electrode and the negative electrode. The spacer may be a power storage element disposed only in a region facing the uncoated region.

  Here, the region facing the uncoated region may be only a position facing the uncoated region, or may include a part of the coated region adjacent to the uncoated region. .

  According to this, the spacer is not provided in the position which opposes the coating area | region which is areas other than the uncoated area | region of an electrode body. Generally, the performance as an electrical storage element falls by the application area | region being overstressed. On the other hand, the uncoated region is a region that is unlikely to cause a decrease in performance of the power storage element even when pressed. And a coating area | region is an area | region which is easy to swell by repeating charging / discharging, and is an area | region where the performance of an electrical storage element will fall easily when it is overstressed. For this reason, by not providing a spacer at a position facing the coating region, it is possible to provide a space that can allow the electrode body to bulge, and prevent the performance of the storage element from deteriorating even if the electrode body expands. Can do.

  Further, in this power storage element, since the spacer is provided only at the position facing the uncoated region in order to increase the vibration resistance, the vibration resistance can be improved without significantly reducing the performance of the power storage element. .

  Preferably, the electrode body is formed by laminating and winding the positive electrode, the negative electrode, and the separator, and the uncoated region is formed in the winding axis direction of the electrode body. The two spacers are provided at both ends and sandwich the coating region, and the spacer is disposed in a region facing each of the two uncoated regions.

  According to the electricity storage device according to the present invention, it is possible to prevent the electrode body from vibrating inside the container, and to prevent performance deterioration of the electricity storage device due to expansion of the electrode body.

It is a perspective view which shows typically the external appearance of the electrical storage element of Embodiment 1 of this invention. It is a disassembled perspective view except the container of an electrical storage element. It is a figure of the state which covered the aggregate | assembly made into the state which the electrode body, the positive electrode collector, the negative electrode collector, and the side surface spacer contact | adhered with the insulating sheet. It is a figure which shows the positional relationship of the electrode body and bottom surface spacer in the inside of an electrical storage element. It is VV sectional drawing of the electrical storage element in FIG. It is VI-VI sectional drawing of the electrical storage element in FIG. It is the top view which looked at the bottom spacer from the right side. It is VIII-VIII sectional drawing of FIG. It is a perspective view of the bottom surface spacer of the electrical storage element which concerns on Embodiment 2 of this invention. It is a perspective view of the bottom surface spacer of the electrical storage element which concerns on Embodiment 3 of this invention. It is sectional drawing in the 1st part of the bottom face spacer which concerns on other embodiment of this invention. It is sectional drawing in the 1st part of the bottom face spacer which concerns on other embodiment of this invention. It is sectional drawing in the 1st part of the bottom face spacer which concerns on other embodiment of this invention. It is a figure which shows the relationship between the electrode body which concerns on other embodiment of this invention, and a bottom face spacer. It is a figure which shows the positional relationship of the electrode body and bottom surface spacer in the inside of the electrical storage element which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. The shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are examples, and are not intended to limit the present invention. The invention is limited only by the claims. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present invention are not necessarily required to achieve the object of the present invention. It will be described as constituting a preferred form.

(Embodiment 1)
FIG. 1 is a perspective view schematically showing the external appearance of a power storage element. FIG. 2 is an exploded perspective view of the storage element without the container.

  The storage element 10 is a secondary battery that can charge electricity and discharge electricity, and more specifically, is a non-aqueous electrolyte battery such as a lithium ion secondary battery.

  As shown in the figure, the electricity storage device 10 includes a container 100, a lid plate 110 provided above the container 100, a positive electrode terminal 200, and a negative electrode terminal 300. In addition, an electrode body 120, a positive electrode current collector 130, a negative electrode current collector 140, side spacers 150 and 160, a bottom spacer 170, and an insulating sheet 180 are disposed inside the container 100.

  Note that a liquid such as an electrolytic solution is sealed inside the container 100 of the power storage element 10, but the liquid is not shown. Moreover, the electrical storage element 10 is not limited to a non-aqueous electrolyte battery, and may be a secondary battery other than the non-aqueous electrolyte battery or a capacitor.

  The container 100 is a container body having a rectangular cylindrical shape made of metal and having a bottom, and an opening of the container body is closed by a metal lid plate 110. In other words, the container 100 can be hermetically sealed by being welded with the lid plate 110 after the electrode body 120 and the like are accommodated therein. In the present embodiment, the surface opposite to the opening of the container 100 is defined as the bottom surface of the container 100.

  Although detailed illustration is omitted, the electrode body 120 includes a positive electrode, a negative electrode, and a separator, and is a member that can store electricity. The positive electrode is obtained by forming a positive electrode active material layer on the surface of a long belt-like positive electrode substrate sheet made of aluminum foil. The negative electrode is obtained by forming a negative electrode active material layer on the surface of a long strip-shaped negative electrode substrate sheet made of copper foil. The separator is a microporous sheet made of resin. The electrode body 120 is formed by winding a layered arrangement so that a separator is sandwiched between a negative electrode and a positive electrode so that the whole becomes an oval shape.

  More specifically, the positive electrode and the negative electrode are wound in an oval shape around the rotation axis along the width direction, shifted from each other in the width direction of the long band via the separator. And the said positive electrode and the said negative electrode are the positive electrode base materials in which the active material is not formed in the one end part of the winding axis | shaft by making the edge part of each shift direction into the non-formation part of an active material The aluminum foil is exposed, and the copper foil, which is a negative electrode base material on which no active material is formed, is exposed at the other end of the winding shaft. Further, a positive electrode current collector 130 and a negative electrode current collector 140 are disposed at both ends of the electrode body 120 in the winding axis direction so as to extend in a direction perpendicular to the winding axis direction.

  In addition, the electrode body 120 is formed with a flat surface portion in which the positive electrode, the negative electrode, and the separator are stacked in a plane, and a curved surface portion in which the electrode body 120 is stacked in a curved surface. The electrode body 120 is accommodated in the container 100 so that the curved surface portion faces the bottom surface of the container 100.

Here, examples of the positive electrode active material include polyanion compounds such as LiMPO ₄ , LiMSiO ₄ , LiMBO ₃ (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), titanic acid, and the like. Use of spinel compounds such as lithium and lithium manganate, lithium transition metal oxides such as LiMO ₂ (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), etc. it can.

Moreover, as a negative electrode active material, if a negative electrode active material which can occlude / release lithium ion, a well-known material can be used suitably. For example, lithium is occluded in addition to lithium metal and lithium alloys (lithium metal-containing alloys such as lithium-silicon, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and wood alloys). Releasable alloys, 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 ) and polyphosphoric acid compounds. In addition, in the same figure, although the ellipse shape was shown as a shape of the electrode body 120, circular shape or elliptical shape may be sufficient.

  The positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode of the electrode body 120, and the negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode of the electrode body 120. That is, the positive electrode terminal 200 and the negative electrode terminal 300 lead the electricity stored in the electrode body 120 to the external space of the power storage element 10, and in order to store the electricity in the electrode body 120, It is an electrode terminal made of metal for introducing. The positive electrode terminal 200 and the negative electrode terminal 300 are attached to the lid plate 110 disposed above the electrode body 120.

  The positive electrode current collector 130 is disposed between the positive electrode of the electrode body 120 and the side wall of the container 100, and is a member having conductivity and rigidity that is electrically connected to the positive electrode terminal 200 and the positive electrode of the electrode body 120. It is. The positive electrode current collector 130 is made of aluminum, like the positive electrode of the electrode body 120.

  The negative electrode current collector 140 is a member that is disposed between the negative electrode of the electrode body 120 and the side wall of the container 100 and has electrical conductivity and rigidity that are electrically connected to the negative electrode terminal 300 and the negative electrode of the electrode body 120. It is. The negative electrode current collector 140 is made of copper, like the negative electrode of the electrode body 120.

  The side spacers 150 and 160 are disposed between the positive electrode current collector 130 and the negative electrode current collector 140 and the side wall of the container 100 and are insulating members. That is, the side spacers 150 and 160 insulate the positive electrode current collector 130 and the negative electrode current collector 140 from the container 100. Further, the side spacers 150 and 160 fill the space between the positive electrode current collector 130 and the negative electrode current collector 140 and the container 100, so that the electrode body 120 is interposed via the positive electrode current collector 130 and the negative electrode current collector 140. Supports the container 100 so as not to vibrate.

  The bottom spacer 170 is an insulating member that is disposed between the electrode body 120 and the bottom surface of the container 100. More specifically, the bottom spacer 170 is disposed between the bottom surface of the container 100 and the curved surface portion of the electrode body 120. That is, the bottom spacer 170 insulates the electrode body 120 from the container 100. Further, the bottom spacer 170 supports the electrode body 120 so as not to vibrate with respect to the container 100 by filling a space between the electrode body 120 and the container 100. The bottom surface spacer 170 includes a support portion 173 that supports the electrode body 120, and two sandwiching portions 174 and 175 that are disposed at both ends of the support portion 173 and sandwich both side surfaces of the electrode body 120. The support portion 173 is a long member, and the longitudinal direction is along the winding axis direction of the electrode body 120. Further, the sandwiching portions 174 and 175 extend along the longitudinal direction of the support portion 173. That is, the bottom spacer 170 is a long member that is long in the longitudinal direction of the support portion 173, the two sandwiching portions 174 and 175 sandwich the front side and the rear side of the bottom of the electrode body 120, and The support portion 173 supports the electrode body 120 so as to cover the bottom surface. Moreover, as for the bottom surface spacer 170, the support part 173 has the groove part 176 as a weak part. The groove portion 176 is formed along the longitudinal direction of the support portion 173.

  The insulating sheet 180 is an insulating sheet-like member that covers the side surface of the electrode body 120. FIG. 3 is a view showing a state in which an assembly in which an electrode body, a positive electrode current collector, a negative electrode current collector, and a side spacer are in close contact with each other is covered with an insulating sheet. As shown in FIG. 3, the insulating sheet 180 covers the side surface of the electrode body 120 for one turn with the arrangement direction of the electrode body 120 and the bottom surface spacer 170 as a winding axis. More specifically, the insulating sheet 180 includes the electrode body 120, the positive electrode current collector 130, the negative electrode current collector 140, and the assembly in which the side spacers 150 and 160 are in close contact with each other. The side surface of the electrode body 120 is covered by one turn with the arrangement direction with the spacer 170 as a winding axis. The insulating sheet 180 covers the side surface of the assembly, and the outer peripheral end thereof is fixed by the adhesive tape 181.

  In addition, as shown in FIG. 3, the power storage element 10 includes an insulating sheet 180 in which the electrode body 120, the positive electrode current collector 130, the negative electrode current collector 140, and the side spacers 150 and 160 are in close contact with each other. After that, the two sandwiching portions 174 and 175 of the bottom surface spacer 170 are inserted into the container 100 with the end portions of the insulating sheet 180 sandwiched with the electrode body 120.

  FIG. 4 is a diagram showing the positional relationship between the electrode body and the bottom spacer inside the electric storage element. In FIG. 4, the positive electrode current collector 130, the negative electrode current collector 140, the side spacers 150 and 160, and the insulating sheet 180 are omitted.

  As described above, the electrode body 120 is provided with the uncoated regions A1 that are regions where the active material is not applied to each of the positive electrode and the negative electrode at both ends in the winding axis direction. A coating region A2, which is a region where the active material is applied, is provided at the center in the winding axis direction of the electrode body 120 between the uncoated regions A1. And the bottom surface spacer 170 has the 1st part 171 which opposes the uncoated area | region A1 of the electrode body 120, and the 2nd part which opposes coating area | region A2. In the bottom spacer 170, the cross-sectional shape of the first portion 171 in a plane orthogonal to the winding axis direction of the electrode body 120 is different from the cross-sectional shape of the second portion 172 in the plane.

  Below, the difference in the cross-sectional shape of the 1st part 171 of the bottom face spacer 170 and the cross-sectional shape of the 2nd part 172 is demonstrated.

  5 is a VV cross-sectional view of the power storage element in FIG. 4. 6 is a VI-VI cross-sectional view of the energy storage device in FIG. 4. FIG. 7 is a plan view of the bottom spacer as viewed from the right side. 8 is a sectional view taken along line VIII-VIII in FIG.

  As shown in FIG. 5, in the bottom spacer 170, the shape of the first portion 171 on the electrode body 120 side is a shape along the outer surface of the electrode body 120. In addition, the bottom spacer 170 has a shape in which the shape of the first portion 171 on the container 100 side is along the inner surface of the container 100. That is, the first portion 171 of the bottom spacer 170 fills almost the entire space between the bottom of the electrode body 120 and the bottom of the container 100, thereby supporting the electrode body 120. On the other hand, as shown in FIG. 6, in the bottom spacer 170, the shape of the second portion 172 on the container 100 side and the shape of the second portion 172 on the electrode body 120 side are shapes along the inner surface of the container 100. In the second portion 172 of the bottom spacer 170, the shape on the electrode body 120 side is a shape obtained by offsetting the shape on the container 100 side. That is, in the second portion 172 of the bottom spacer 170, the thickness of the support portion 173 and the two sandwiching portions 174 and 175 is constant Δt2. 8, in the bottom spacer 170, the thickness Δt1 of the first portion 171 is thicker than the thickness Δt2 of the second portion 172. For this reason, the gap between the second portion 172 of the bottom spacer 170 and the coating region A2 of the electrode body 120 is larger than the gap between the first portion 171 of the bottom spacer 170 and the uncoated region A1 of the electrode body 120.

  In addition, the groove part 176 as a weak part is formed in the 1st part 171 of the bottom face spacer 170. FIG. The thickness Δt3 of the first portion 171 in the groove 176 is equal to the thickness Δt2 of the second portion 172.

  According to the electricity storage device 10 according to the first embodiment, the thickness Δt1 of the first portion 171 of the bottom spacer 170 at positions corresponding to both ends of the electrode body 120 in the winding axis direction is thicker than the thickness Δt2 of the second portion 172. Therefore, the space inside the container 100 corresponding to the position can be almost filled with the electrode body 120 and the bottom spacer 170, and the electrode body 120 can be prevented from vibrating inside the container. For this reason, the vibration resistance of the electrical storage element 10 can be improved.

  Further, the electrode body 120 is deteriorated in performance as the power storage element 10 due to excessive pressing of the coating region A2. On the other hand, the uncoated area A <b> 1 of the electrode body 120 is an area that is unlikely to cause a decrease in performance of the power storage element 10 even when pressed. In this power storage element 10, in order to increase the vibration resistance, the thickness Δt1 of the first portion 171 of the bottom spacer 170 facing the uncoated region A1 is made thicker than the second portion 172 to press the uncoated region A1. Therefore, vibration resistance can be improved without significantly reducing the performance of the electricity storage element 10.

  In addition, the thickness Δt2 of the second portion 172 of the bottom spacer 170 at a position facing the coating region A2 that is a region other than the uncoated region A1 of the electrode body 120 is thinner than the thickness Δt1 of the first portion 171. The coating region A2 is a region that easily swells by repeating charge and discharge, and is a region in which the performance of the power storage element 10 is likely to deteriorate when excessively compressed. For this reason, by making the thickness Δt2 of the second portion 172 of the bottom spacer 170 thinner than the thickness Δt1 of the first portion 171, a space that can allow the electrode body 120 to bulge can be provided, and the electrode body 120 expands. Moreover, it can prevent that the performance of the electrical storage element 10 falls.

  According to the electricity storage element 10 according to the first embodiment, the container 100 at a position where the gap (clearance) between the electrode body 120 and the position facing the coating area A2 faces the uncoated area A1 of the electrode body 120. A bottom spacer 170 is formed so as to be larger than the clearance of the electrode body 120 with respect to. For this reason, even if the coating area A2 expands due to repeated charge and discharge, the electrode body 120 has a large clearance at a position facing the coating area A2, and thus allows the coating area A2 of the electrode body 120 to expand. it can. Further, since the electrode body 120 has a small clearance in the uncoated region A1 in which the performance degradation of the power storage element 10 due to pressure is unlikely to occur, the vibration resistance is improved in a state where the performance degradation of the power storage element 10 does not occur. Can be made.

  According to the electricity storage device 10 according to the first embodiment, since the shape of the first portion 171 of the bottom surface spacer 170 on the electrode body 120 side is a shape along the electrode body 120, the gap between the position facing the first portion 171 ( (Clearance) can be minimized. For this reason, the bottom spacer 170 can further improve the vibration resistance in the first portion 171.

  In addition, the spacer like patent document 1 has an acute angle | corner boundary part comprised by the curved surface along the curved surface of an electrode body, and the outer surface along the inner surface of a container. For this reason, when the spacer is disposed on the electrode body, if the position of the electrode body and the spacer is slightly shifted, the sharp boundary portion of the spacer may hit the curved surface portion of the electrode body and damage the electrode body. Further, in the spacer having the sandwiching portion as described above, the electrode body may be damaged when the electrode body is sandwiched by the sandwiching portion.

  According to the electricity storage device 10 according to the above embodiment, the bottom spacer 170 is disposed at both ends of the support part 173 that supports the electrode body 120 and the support part 173 and along the longitudinal direction of the support part 173. , And sandwiching portions 174 and 175 that sandwich the electrode body 120, and a weak portion is formed in the support portion 173. For this reason, the supporting portion 173 should be structured to be easily bent so that the clamping portions 174 and 175 provided at both ends of the supporting portion 173 open with the weakened portion (or the vicinity thereof) formed in the supporting portion 173 as a base point. Can do. For this reason, the outer periphery of the electrode body 120 formed by a curved surface can be easily sandwiched by the sandwiching portions 174 and 175, and the bottom spacer 170 can be easily along the electrode body 120. For this reason, a spacer can be easily arrange | positioned so that the electrode body 120 may not be damaged.

  According to power storage element 10 according to the first embodiment, groove portion 176 as a weak portion is formed only in first portion 171 thicker than second portion 172 of bottom spacer 170. For this reason, the 1st part 171 which is thicker than the 2nd part 172, and is a structure hard to bend can be made into a structure which is easy to bend.

  According to the electricity storage device 10 according to the first embodiment, since the thickness Δt3 of the thin portion formed on the bottom spacer 170 is equal to the thickness Δt2 of the second portion 172, the bottom spacer 170 extends in the winding axis direction. It is possible to make the structure easy to bend with the thin portion as a base point.

  According to the electricity storage device 10 according to the first embodiment, the bottom spacer 170 has the groove portion 176 formed in the support portion 173 over the winding axis direction. For this reason, the support portion 173 of the bottom surface spacer 170 can be easily bent with the groove portion 176 extending in the winding axis direction as a base point.

  According to the electricity storage device 10 according to the first embodiment, since the bottom spacer 170 can be covered so as to overlap the insulating sheet 180 covering the side surface of the electrode body 120, the portion where the insulating sheet 180 and the bottom spacer 170 overlap. Insulation can be improved. In addition, since the bottom spacer 170 overlaps the outside of the insulating sheet 180, the insulating sheet 180 is covered with the electrode body 120, and the bottom spacer 170 is further covered with the electrode body 120 and inserted into the container 100. The insulating sheet 180 can be prevented from turning up from the end portion of the electrode body 120 on the side where the bottom spacer 170 is disposed. For this reason, it can prevent that the electrical storage element 10 in which the insulation of the electrode body 120 fell can be prevented, and the productivity of the electrical storage element 10 can be improved.

(Embodiment 2)
The first portion 171 of the bottom surface spacer 170 of the electricity storage device 10 according to the first embodiment is provided with the groove 176 as the fragile portion, but the groove 176 may not be provided.

  FIG. 9 is a perspective view of the bottom spacer of the energy storage device according to Embodiment 2 of the present invention. The bottom surface spacer 270 shown in FIG. 9 is different only in that the groove portion 176 of the bottom surface spacer 170 of the first embodiment is not provided, and each configuration other than the groove portion 176 of the bottom surface spacer 170 is changed from the 100th number to the 200th number. It can be explained by replacing it. For this reason, description of each part is abbreviate | omitted.

(Embodiment 3)
In the bottom spacers 170 and 270 of the first embodiment or the second embodiment, the first portions 171 and 271 and the second portions 172 and 272 have different cross-sectional shapes, but the present invention is not limited to this.

  FIG. 10 is a perspective view of the bottom spacer of the energy storage device according to Embodiment 3 of the present invention. The bottom surface spacer 370 shown in FIG. 10 has the same cross-sectional shape of the first portion 371 facing the uncoated area A1 of the electrode body 120 and the cross-sectional shape of the second portion 372 facing the coated area A2 of the electrode body 120. is there. In addition, the compression rate of the first portion 371 when a predetermined compression force is applied is smaller than the compression rate of the second portion 372 when the compression force is applied. Here, as a material adopted for the first portion 371 having a small compression rate, for example, a resin material having no bubbles or the like can be considered. Moreover, as a material employ | adopted for the 2nd part 372 with a large compression rate, resin materials, such as sponge with a bubble inside, etc. can be considered, for example.

  According to this, since the compressibility of the first portion of the spacer at positions corresponding to both ends of the electrode body in the winding axis direction is smaller than the compressibility of the second portion, the second portion Can be less compressed. For this reason, the space inside the container corresponding to the position can be substantially filled with the electrode body and the spacer, and the electrode body can be prevented from vibrating inside the container. For this reason, the vibration resistance of an electrical storage element can be improved.

  Moreover, the performance as an electrical storage element falls by the application area | region being pressed too much. On the other hand, the uncoated region is a region that is unlikely to cause a decrease in performance of the power storage element even when pressed. In this electricity storage device, in order to increase the vibration resistance, the compression ratio of the first portion of the spacer facing the uncoated region is made smaller than the compression rate of the second portion to press the uncoated region, Vibration resistance can be improved without significantly reducing the performance of the power storage element.

  Moreover, the compression rate of the second part of the spacer at a position facing the coating region which is a region other than the uncoated region of the electrode body is larger than the compression rate of the first part. The coating region is a region that easily swells due to repeated charge and discharge, and is a region in which the performance of the electricity storage element is likely to deteriorate when excessively compressed. For this reason, when the compression ratio of the second part of the spacer is made larger than the compression ratio of the first part, when the force for pushing the second part is generated due to the expansion of the electrode body, the second part is compressed and the electrode body expands. Therefore, even if the electrode body expands, it is possible to prevent the performance of the power storage element from being deteriorated.

(Other embodiments)
In the bottom surface spacer 170 of the first embodiment, one groove portion 176 extending along the longitudinal direction of the support portion 173 is provided as the weak portion, but the weak portion provided in the support portion 173 is one groove portion 176. Not limited to.

  11A to 11C are cross-sectional views of a first portion of a bottom spacer according to another embodiment.

  For example, as shown in FIG. 11A, a bottom spacer 170a in which two groove portions 176a extending along the longitudinal direction of the support portion 173 are provided in the support portion 173 as weak portions may be employed.

  Further, as shown in FIG. 11B, a bottom spacer 170b in which a notch 176b extending along the longitudinal direction of the support portion 173 is provided as a weak portion in the support portion 173 may be employed.

  Further, as shown in FIG. 11C, a bottom spacer 170c in which a groove 176c extending along the longitudinal direction is provided as a fragile portion on the support portion 173 on the surface of the support portion 173 on the container 100 side may be employed.

  Thus, the weak part provided in a bottom face spacer may be either a groove part or a notch part, and the number of weak parts formed in a bottom face spacer is not limited. Furthermore, in the said embodiment, although the groove part and notch part as a weak part are provided in the support part 173, you may provide in either of the clamping parts 174 and 175. FIG. Moreover, as a weak part, not only the groove part and the notch part of the shape extended in a longitudinal direction but the some through-hole arranged along a longitudinal direction may be sufficient. In addition, when it is a several through-hole, it is preferable that it is a magnitude | size of the grade which can take insulation of the container 100 and the electrode body 120 enough.

  Moreover, the groove part 176 as a weak part formed in the 1st part 171 should just form the thin part thinner than the other part in the 1st part 171 not only in the groove part 176, For example, a thin portion having a thickness equal to, for example, Δt3 may be formed in the support portion 173 by forming the cut along the longitudinal direction of the support portion 173.

  Moreover, although it is preferable that the location in which the 1st part 171,271,371 is formed is the uncoated area | region A1 of the electrode body 120, it does not need to correspond exactly | strictly. That is, the cross-sectional shape of the bottom spacer may be such that the cross-sectional shape of the first portion at the position facing the uncoated region A1 is as described above, and the cross-sectional shape of the second portion as it goes to the coating region A2 side. It may be changed gradually or gradually so as to approach the cross-sectional shape of the first part from the cross-sectional shape of the second part.

  In addition, the bottom spacer 170 according to the first embodiment has two first portions 171 continuous with the second portion 172. However, like the bottom spacer 470 shown in FIG. 12, only the first portion 471 is configured. The two bottom spacers 470 may be used. The electrode body 120 has the same configuration as that of the electrode body 120 of the first embodiment, and the coating region A2 where the active material is coated on the surfaces of the positive electrode and the negative electrode, and both ends in the winding axis direction of the electrode body And two uncoated areas A1 where the active material is not coated on the surfaces of the positive electrode and the negative electrode. And the two bottom spacers 470 are arrange | positioned in the position facing each of coating area | region A1. In addition, FIG. 12 is a figure which shows the relationship between the electrode body which concerns on other embodiment of this invention, and a bottom face spacer. Each configuration of the bottom spacer 470 is different only in the absence of the second portion 172 of the bottom spacer 170 according to the first embodiment, and can be described by replacing the reference numerals in the 100s with the 400s, so the description of each part is omitted. .

  According to this, the bottom surface spacer 470 is not provided at a position facing the coating region A2 which is a region other than the uncoated region A1 of the electrode body 120. Generally, the performance as the electrical storage element 10 is deteriorated in the coating region A2 due to excessive pressure. On the other hand, the uncoated region A1 is a region in which the performance degradation of the power storage element 10 is unlikely to occur even when pressed. And coating area | region A2 is an area | region which is easy to swell by repeating charging / discharging, and is an area | region where the performance of the electrical storage element 10 will fall easily when it is overstressed. For this reason, by not providing the bottom spacer at a position facing the coating region A2, a space allowing the swelling of the electrode body 120 can be provided, and the performance of the storage element 10 is degraded even when the electrode body 120 expands. Can be prevented.

  In addition, in this power storage element 10, since the bottom spacer 470 is provided only at the position facing the uncoated region A1 in order to enhance the vibration resistance, the vibration resistance is not reduced so much. Can be increased.

  Further, the place where the two bottom spacers 470 are disposed is preferably the uncoated area A1 of the electrode body 120, but does not have to be exactly coincident as shown in FIG. That is, even if the bottom spacer 470 is disposed in the region B1 facing at least the uncoated region A1 and facing a part of the coated region A2 adjacent to the uncoated region A1, the above-described effect is achieved. There is. That is, the bottom spacer 470 may not be disposed in the region where the electrode body 120 swells. As shown in FIG. 13, the third region B3 is a region where the width of the electrode body 120 is shorter or equal to the winding axis direction compared to the second region B2, and the widths in the other directions are equal. It is an area. FIG. 13 is a diagram illustrating a positional relationship between the electrode body and the bottom spacer in the electric storage element.

  Further, in power storage element 10 according to Embodiment 1 and Embodiment 2 described above, the structure of electrode body 120 is a wound type, but is not limited to a wound type, and may be a stacked type.

  As mentioned above, although the component mounting method of this invention was demonstrated based on embodiment, this invention is not limited to this embodiment. Unless it deviates from the meaning of this invention, the form which carried out the various deformation | transformation which those skilled in the art can think to this embodiment, and the structure constructed | assembled combining the component in different embodiment is also contained in the scope of the present invention. .

  An electricity storage device according to one embodiment of the present invention is an electricity storage device including a spacer between a container and an electrode body, and prevents the electrode body from vibrating inside the container and the electrode body is expanded. It is useful as a power storage element that can prevent a decrease in performance.

10 Storage element 100 Container 110 Cover plate 120 Electrode body 130 Positive electrode current collector 140 Negative electrode current collector 150, 160 Side spacers 170, 170a, 170b, 170c, 270, 370, 470 Bottom spacers 171, 271, 371 First portion 172, 272, 372 Second portion 173, 273, 373, 473 Support portion 174, 175, 274, 275, 374, 375, 474, 475 Nipping portion 176, 176a, 176c, 476 Groove portion 176b Cut portion 180 Insulating sheet 181 Adhesive tape 200 Positive electrode terminal 300 Negative electrode terminal A1 Uncoated region A2 Coating region Δt1 First portion thickness Δt2 Second portion thickness Δt3 Thin portion thickness

Claims (7)

An electrode body in which a positive electrode and a negative electrode coated with an active material on the surface, and a separator are laminated;
A container for housing the electrode body;
A spacer disposed between the electrode body and the container;
With
The electrode body includes: (i) a coated region in which an active material is coated on the surfaces of the positive electrode and the negative electrode; and an uncoated region in which an active material is not coated on the surfaces of the positive electrode and the negative electrode. And (ii) a plane part in which the positive electrode, the negative electrode, and the separator are laminated and wound, and the positive electrode, the negative electrode, and the separator are laminated in a plane. And a curved surface portion laminated with a curved surface,
The spacer is
A first portion facing the uncoated region and a second portion facing the coated region ;
Between the coating region of said curved surface portion of the electrode body and the second portion of the spacer, the second interval in the arrangement direction of the spacers and the curved portion of the curved surface portion of the electrode body In any position, the power storage element that is larger than the first interval in the arrangement direction between the first portion of the spacer and the uncoated region of the curved surface portion of the electrode body. The container has a shape covering a substantially rectangular parallelepiped space,
The spacer is
Arranged between the curved surface portion of the electrode body and the container;
The shape of the first part on the electrode body side is a shape along the outer surface of the electrode body,
The shape of the electrode side of the second portion, the electric storage device according to claim 1, wherein the shape along the inner surface of the container. The electrode body is accommodated in the container so that the curved surface portion faces the bottom surface of the container,
The spacer, the electric storage device according to claim 1 or 2 is disposed between the curved surface portion of the electrode body and the bottom surface of the container. The spacer includes a support portion that supports the electrode body, and two sandwiching portions that are disposed at both ends of the support portion and sandwich both side surfaces of the electrode body,
The support portion has a long shape,
The power storage device according to any one of claims 1 to 3 , wherein the support part and / or the clamping part has a groove part extending along a longitudinal direction of the support part. The power storage element according to claim 4 , wherein the groove is formed in the first portion of the spacer. The electric storage element according to claim 4 or 5 , wherein a thickness of the support portion and / or the clamping portion in the groove portion is equal to a thickness of the second portion. further,
An insulating sheet covering a side surface of the electrode body;
The power storage element according to any one of claims 4 to 6 , wherein the sandwiching portion of the spacer sandwiches an end portion of the insulating sheet together with the electrode body.

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