Electricity storage unit

Abstract

A power storage cell is provided with a pair of electrode bodies each comprising a wound body. Each electrode body includes a coated portion, an uncoated portion, and a collector tab. The uncoated portion has an outer end surface, an inner end surface, and a connecting surface. The collector tab protrudes from at least one of the inner end surface and the connection surface. The outer end face of one electrode body is opposite to the inner end face of the other electrode body. The inner side end face of one electrode body is opposite to the outer side end face of the other electrode body. The connection surface of one electrode body faces the connection surface of the other electrode body in a direction intersecting the axial direction. And the collector lug of one electrode body is connected with the collector lug of the other electrode body.

Description

Technical Field

[0001] The present disclosure relates to a power storage unit. Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 2016-207516 discloses a battery comprising a wound electrode body, a battery case housing the wound electrode body, and electrode terminals connected to collector tabs of the wound electrode body. The collector tabs protrude upward from a power generation region. Summary of the Invention

[0003] The power storage unit described in Japanese Patent Application Laid-Open No. 2016-207516 preferably has a high energy density.

[0004] An object of the present disclosure is to provide a power storage unit capable of improving energy density.

[0005] According to one aspect of the present disclosure, a storage unit comprises a pair of electrode bodies each consisting of a wound body, each of the electrode bodies comprising: a coated portion comprising a collector foil and an active material layer provided on the collector foil; an uncoated portion protruding from the coated portion in the axial direction of the coated portion and consisting only of the collector foil; and a collector ear protruding from the uncoated portion, the uncoated portion having: an outer end face formed on the outer side in the axial direction; an inner end face formed on the inner side of the outer end face in the axial direction; and a connecting face connecting the outer end face to the inner end face, the collector The ear protrudes from at least one of the inner end surface and the connecting surface, the outer end surface of one of the pair of electrode bodies faces the inner end surface of the other electrode body, the inner end surface of one of the pair of electrode bodies faces the outer end surface of the other electrode body, the connecting surface of one of the pair of electrode bodies faces the connecting surface of the other electrode body in a direction intersecting the axial direction, and the collector ear of one electrode body is connected to the collector ear of the other electrode body.

[0006] According to the present disclosure, it is possible to provide a power storage unit capable of improving energy density. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Features, advantages, technical and industrial significance of embodiments of the present invention are described below with reference to the accompanying drawings, wherein like reference numerals denote like elements.

[0008] Figure 1 This is a perspective view schematically showing an electric storage unit in one embodiment of the present disclosure.

[0009] Figure 2 This is the main view of the unit component.

[0010] Figure 3This is a front view of the electrode body.

[0011] Figure 4 It is a three-dimensional diagram of the electrode body.

[0012] Figure 5 It is a perspective view showing a modified example of the electrode body. DETAILED DESCRIPTION

[0013] The embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are denoted by the same reference numerals.

[0014] Figure 1 This is a perspective view schematically showing an electric storage unit in one embodiment of the present disclosure. Figure 2 This is the main view of the unit component. Figure 3 This is a front view of the electrode body. Figure 4 This is a perspective view of an electrode assembly. The electricity storage unit 1 is mounted on the bottom of a vehicle, for example.

[0015] like Figures 1 to 4 As shown, the power storage unit 1 includes a plurality of cell assemblies 100 , a cell case 300 , and external terminals 400 .

[0016] The plurality of unit assemblies 100 include at least one pair of unit assemblies 100. Each unit assembly 100 includes an electrode body 110 and a laminated outer casing 160.

[0017] The electrode body 110 is composed of a wound body formed by winding a positive electrode sheet and a negative electrode sheet with a separator interposed therebetween. The electrode body 110 is formed so that the positive electrode sheet and the negative electrode sheet are wound in the axial direction of the wound body ( Figure 3 The electrode body 110 has a long shape in the left-right direction (in the horizontal direction). The electrode body 110 includes a coated portion 112, an uncoated portion 114, and a collector tab 116.

[0018] The coating portion 112 includes a collector foil F (see Figure 3 ) and the active material layer M provided on the collector foil F (refer to Figure 3 The collector foil F is made of metal foil. The active material layer M is provided on the surface of the collector foil F. Figure 3 and Figure 4 In FIG, the application portion 112 is represented by a dot pattern.

[0019] The uncoated portion 114 protrudes in the axial direction from the coated portion 112. The uncoated portion 114 is composed only of the collector foil F. The uncoated portion 114 has an outer end surface S1, an inner end surface S2, and a connecting surface S3.

[0020] The outer end surface S1 is formed on the outer side in the axial direction and is formed to be substantially flat.

[0021] The inner end surface S2 is formed inside the outer end surface S1 in the axial direction and is formed to be substantially flat.

[0022] The connecting surface S3 connects the outer end surface S1 and the inner end surface S2. The connecting surface S3 is along the axial direction. In this embodiment, the connecting surface S3 is parallel to the axial direction.

[0023] like Figure 3 As shown, the outer end surface S1 of one electrode body 110 of the pair of electrode bodies 110 faces the inner end surface S2 of the other electrode body 110. The inner end surface S2 of one electrode body 110 of the pair of electrode bodies 110 faces the outer end surface S1 of the other electrode body 110. The connecting surface S3 of one electrode body 110 of the pair of electrode bodies 110 faces the connecting surface S3 of the other electrode body 110 in a direction intersecting the axial direction.

[0024] The collector tab 116 protrudes from the uncoated portion 114. In this embodiment, the collector tab 116 protrudes from the inner end surface S2. The collector tab 116 is composed of a collector foil F. The collector tab 116 is integrally connected to the collector foil F constituting the uncoated portion 114. Figure 2 and Figure 3 As shown, the collector tab 116 of one electrode body 110 is connected to the collector tab 116 of another electrode body 110 .

[0025] The laminated outer package 160 houses the electrode body 110. The laminated outer package 160 is made of a laminate film. Figure 2 As shown, the laminated outer casing 160 has an edge 162 . The edge 162 is formed by connecting (welding) laminate films to each other. The current collector tab 116 protrudes from the edge 162 of the laminated outer casing 160 .

[0026] The laminated outer casing 160 includes an outer covering portion 162a, an inner covering portion 162b, and a connecting covering portion 162c. The outer covering portion 162a faces the outer end surface S1. The inner covering portion 162b faces the inner end surface S2. The connecting covering portion 162c faces the connecting surface S3. The collector tab 116 protrudes from the inner covering portion 162b.

[0027] The unit housing 300 accommodates a plurality of unit assemblies 100. The unit housing 300 is made of, for example, aluminum. The unit housing 300 is formed in a rectangular parallelepiped shape. Figure 1 As shown, the unit housing 300 has a housing body 310 and a cover 320 .

[0028] The housing body 310 is formed in a square cylindrical shape and surrounds the plurality of cell assemblies 100. Alternatively, the plurality of cell assemblies 100 may be covered with a covering sheet (not shown) made of an insulating material (such as synthetic resin), and the housing body 310 surrounds the plurality of cell assemblies 100 and the covering sheet.

[0029] The cover 320 is connected to the case body 310 by welding or the like so as to close the opening of the case body 310 . The cover 320 is provided with a pair of external terminals 400 .

[0030] As described above, in the storage cell 1 of this embodiment, the connecting surfaces S3 of the pair of electrode bodies 110 face each other in a cross-direction intersecting the axial direction. In other words, a portion of the uncoated portion 114 of one electrode body 110 overlaps with a portion of the uncoated portion 114 of the other electrode body 110 in the cross-direction. Therefore, compared to a case where the uncoated portions 114 of a pair of electrode bodies 110 do not overlap in the cross-direction but rather the outer end surfaces of the uncoated portions 114 face each other in the axial direction, the size of each electrode body 110 in the axial direction is reduced. As a result, the size of each electrode body 110 can be increased accordingly, that is, the energy density can be improved.

[0031] In addition, if Figure 5 As shown, the collector tab 116 may also protrude from the connecting surface S3 in the intersecting direction.

[0032] Those skilled in the art will appreciate that the above exemplary embodiments are specific examples in the following aspects.

[0033] [Form 1]

[0034] A storage cell, comprising a pair of electrode bodies each consisting of a wound body, each of the electrode bodies comprising: a coated portion comprising a collector foil and an active material layer provided on the collector foil; an uncoated portion protruding from the coated portion in the axial direction of the coated portion and consisting only of the collector foil; and a collector tab protruding from the uncoated portion, the uncoated portion having: an outer end face formed on the outer side in the axial direction; an inner end face formed on the inner side of the outer end face in the axial direction; and a connecting face connecting the outer end face and the inner end face, the collector tab extending from the uncoated portion. At least one of the inner end face and the connecting face protrudes, the outer end face of one of the pair of electrode bodies faces the inner end face of the other electrode body, the inner end face of one of the pair of electrode bodies faces the outer end face of the other electrode body, the connecting face of one of the pair of electrode bodies faces the connecting face of the other electrode body in a direction intersecting the axial direction, and the collector ear of one electrode body is connected to the collector ear of the other electrode body.

[0035] In this battery cell, the connecting surfaces of the pair of electrode bodies face each other in a direction intersecting the axial direction. Therefore, the axial dimensions of each electrode body are reduced compared to a case where the outer end surfaces of the pair of electrode bodies face each other in the axial direction. Consequently, the size of each electrode body can be increased accordingly, which in turn increases energy density.

[0036] [Form 2]

[0037] The storage battery unit according to embodiment 1 further comprises a laminated outer casing for housing each of the electrode bodies, the laminated outer casing having an outer covering portion facing the outer end surface, an inner covering portion facing the inner end surface, and a connecting covering portion facing the connecting surface.

[0038] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The scope of the present disclosure is indicated by the claims rather than the above-described embodiments, and all modifications within the meaning and scope equivalent to the claims are also encompassed.

Claims

1. A power storage unit comprising a pair of electrode bodies each consisting of a wound body, Each of the electrode bodies comprises: The coating portion includes a current collector foil and an active material layer disposed on the current collector foil; an uncoated portion protruding from the coated portion in the axial direction of the coated portion and consisting only of the collector foil; and a collector lug protruding from the uncoated portion, The uncoated portion has: an outer end surface formed on the outer side in the axial direction; an inner end surface formed on the inner side of the outer end surface in the axial direction; and a connecting surface connecting the outer end surface and the inner end surface, The collector ear protrudes from at least one of the inner end surface and the connecting surface. The outer end surface of one of the pair of electrode bodies faces the inner end surface of the other electrode body, The inner end surface of one of the pair of electrode bodies faces the outer end surface of the other electrode body. The connecting surface of one of the pair of electrode bodies faces the connecting surface of the other electrode body in a direction intersecting the axial direction. The collector tab of one electrode body is connected to the collector tab of the other electrode body.

2. The power storage unit according to claim 1, wherein The electricity storage unit further includes a laminated outer casing that houses the electrode bodies. The laminated outer body has: an outer covering portion facing the outer end surface; an inner covering portion facing the inner end surface; and The connecting covering portion faces the connecting surface.

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