Power storage module

Abstract

To provide a power storage module with improved volumetric efficiency.SOLUTION: A power storage module 1 comprises a plurality of first storage cells 10 arranged in such a manner that their axial directions are substantially parallel to each other, at least one second storage cell 20 arranged in such a manner that it is surrounded by the plurality of first storage cells 10, and a case 30 that houses the plurality of first storage cells 10 and the second storage cell 20, and each of the plurality of first storage cells 10 and the second storage cell 20 has a cylindrical shape, and the diameter of each of the plurality of first storage cells 10 is larger than the diameter of the second storage cell 20.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a power storage module.

Background Art

[0002] Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2016-178048) discloses a battery module including a plurality of cylindrical power storage cells.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, with the increase in the capacity of power storage cells, the size of power storage cells has been increasing. In addition, cylindrical power storage cells are widely used because they can be mass-produced at a relatively low cost.

[0005] On the other hand, since the shape is cylindrical, in a power storage module equipped with a plurality of power storage cells, gaps are generated between the power storage cells. Such gaps become larger as the power storage cells increase in size, resulting in a decrease in the volume efficiency of the power storage module.

[0006] The present disclosure has been made to solve the above problems, and an object thereof is to provide a power storage module with improved volume efficiency.

Means for Solving the Problems

[0007] 〔1〕 A plurality of first power storage cells arranged such that their axial directions are substantially parallel to each other, At least one second power storage cell arranged so as to be surrounded by the plurality of first power storage cells, A case that houses the plurality of first power storage cells and the second power storage cell, and each of the plurality of first power storage cells and the second power storage cell has a cylindrical shape, A power storage module in which the diameter of each of the plurality of first power storage cells is larger than the diameter of the second power storage cell.

[0008] According to the present disclosure, the volume efficiency of the power storage module can be improved.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

[0011] The power storage module of the present disclosure is mounted on, for example, an electric vehicle. The power storage cell of the present disclosure is, for example, a lithium ion battery. Note that the use of the power storage module is not limited to vehicle use. Further, when simply referred to as a "power storage cell" in the present disclosure, the power storage cell includes a first power storage cell and a second power storage cell.

[0012] [First Embodiment] FIG. 1 is a plan view showing the overall configuration of a power storage module 1 according to a first embodiment of the present disclosure. The power storage module 1 includes a plurality (six in FIG. 1) of first power storage cells 10, at least one (two in FIG. 1) of second power storage cells 20, and a case 30. The number of each of the first power storage cells 10 and the second power storage cells 20 is not limited to the above example. Hereinafter, the power storage module 1 including a plurality of second power storage cells 20 will be described. Note that FIG. 1 is a plan view of the power storage module 1 with the upper lid described later removed.

[0013] Each of the plurality of first power storage cells 10 has a cylindrical shape. The plurality of first power storage cells 10 may be arranged such that each first power storage cell 10 is adjacent to each other, or may be arranged to be close to each other. The plurality of first power storage cells 10 are arranged such that their axial directions are substantially parallel to each other (for example, the deviation angle between the axial directions is within 1 degree). Note that the above axial direction is the Z direction shown in FIG. 1. Also, the Z direction is, for example, the vertical direction, and the Z1 direction and the Z2 direction are the upper and lower directions, respectively. Note that the Z direction may be other than the vertical direction (for example, the horizontal direction).

[0014] Each of the plurality of second power storage cells 20 is arranged so as to be surrounded by the plurality of first power storage cells 10. Specifically, each of the plurality of second power storage cells 20 is provided in a gap S formed between four first power storage cells 10 arranged adjacent (close) to each other. By providing the second power storage cells 20 in this way, the volume efficiency of the power storage module 1 can be improved.

[0015] Each of the plurality of second power storage cells 20 has a columnar shape. Each of the plurality of second power storage cells 20 extends along the Z direction. That is, the axial direction of each of the plurality of second power storage cells 20 extends along the Z direction.

[0016] When viewed along the Z direction, each of the plurality of first power storage cells 10 has a diameter d1. When viewed along the Z direction, each of the plurality of second power storage cells 20 has a diameter d2. The diameter d1 is larger than the diameter d2. That is, each first power storage cell 10 is a power storage cell larger than each second power storage cell 20. For example, the diameter d1 may be twice or more, or four times or more, the diameter d2.

[0017] The case 30 houses each of the plurality of first power storage cells 10. The case 30 houses each of the plurality of second power storage cells 20. The case 30 may be formed of, for example, iron or aluminum.

[0018] As shown in FIG. 2, the case 30 includes an upper lid 31, a bottom surface 32, and a side surface 33 (see FIG. 1) connecting the upper lid 31 and the bottom surface 32.

[0019] The end portion 11 on the Z1 side of each of the plurality of first power storage cells 10 may be in contact with or separated from the upper lid 31. The end portion 21 on the Z1 side of each of the plurality of second power storage cells 20 may be in contact with or separated from the upper lid 31. When the end portion 11 on the Z1 side of each of the plurality of first power storage cells 10 and the end portion 21 on the Z1 side of each of the plurality of second power storage cells 20 are separated from the upper lid 31, a cooler, for example, may be disposed therebetween.

[0020] The end portion 12 on the Z2 side of each of the plurality of first power storage cells 10 may be in contact with or separated from the bottom surface 32. The end portion 22 on the Z2 side of each of the plurality of second power storage cells 20 may be in contact with or separated from the bottom surface 32. When the end portion 12 on the Z2 side of each of the plurality of first power storage cells 10 and the end portion 22 on the Z2 side of each of the plurality of second power storage cells 20 are separated from the upper lid 31, a cooler, for example, may be disposed therebetween. Note that the plurality of first power storage cells 10 and the plurality of second power storage cells 20 may be placed (fixed) on the bottom surface 32, for example.

[0021] FIG. 3 is a schematic perspective view showing the configuration of the wound electrode body 100 included in the storage cell according to the present embodiment. The wound electrode body 100 includes a positive electrode plate 110, a negative electrode plate 111, and a separator 112. The separator 112 is provided between the positive electrode plate 110 and the negative electrode plate 111. That is, the positive electrode plate 110, the separator 112, and the negative electrode plate 111 are laminated on each other. The separator 112 separates the positive electrode plate 110 and the negative electrode plate 111 while allowing ions (e.g., lithium ions) to move between the positive electrode plate 110 (positive electrode active material) and the negative electrode plate 111 (negative electrode active material). The wound electrode body 100 is composed of a group of electrode plates in which the positive electrode plate 110 and the negative electrode plate 111 are wound via the separator 112. The positive electrode plate 110, the separator 112, and the negative electrode plate 111 are wound around the winding axis α.

[0022] The positive electrode plate 110 includes a positive electrode current collector plate and a positive electrode composite layer. The positive electrode current collector plate is formed of a metal material such as aluminum or an aluminum alloy, for example.

[0023] The positive electrode composite layer contains a positive electrode active material, a binder, and the like. Examples of the positive electrode active material include LiCoO2, LiNo2, LiMn2O4, and the like. The thickness of the positive electrode composite layer is, for example, 0.1 μm or more and 1000 μm or less. The positive electrode composite layer is formed on both the front and back surfaces of the positive electrode current collector plate, but may be formed on one surface.

[0024] The negative electrode plate 111 includes a negative electrode current collector plate and a negative electrode composite layer. The negative electrode current collector plate contains a metal material such as copper, for example.

[0025] The negative electrode composite layer contains a negative electrode active material, a binder, and the like. Examples of the negative electrode active material include graphite and the like. The thickness of the negative electrode composite layer is, for example, 0.1 μm or more and 1000 μm or less. The negative electrode composite layer is formed on both the front and back surfaces of the negative electrode current collector plate, but may be formed on one surface.

[0026] As described above, in the first embodiment, each of the plurality of second power storage cells 20 is provided in a gap S formed between four first power storage cells 10 arranged adjacent (proximate) to each other. By providing the plurality of second power storage cells 20 between the first power storage cells 10 in this way, the volume efficiency of the power storage module 1 can be improved.

[0027] [Second Embodiment] Referring to FIG. 4, a second embodiment of the present disclosure will be described. For the same configurations as those in the first embodiment, the same reference numerals as those in the first embodiment will be given and repeated descriptions will not be provided.

[0028] The power storage module 1 according to the second embodiment includes, similarly to the first embodiment, a plurality (six in FIG. 4) of first power storage cells 10, at least one (four in FIG. 4) of second power storage cells 20, and a case 30.

[0029] Each of the plurality of second power storage cells 20 is arranged so as to be surrounded by the plurality of first power storage cells 10. Specifically, each of the plurality of second power storage cells 20 is provided in a gap S' formed between three first power storage cells 10 arranged adjacent (proximate) to each other. By providing the plurality of second power storage cells 20 in this way, the volume efficiency of the power storage module 1 can be improved.

[0030] Note that for other configurations and effects, since they are the same as those in the first embodiment, repeated descriptions will not be provided.

[0031] Note that the configurations of the above embodiments may be combined with each other.

[0032] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is shown not by the description of the above embodiments but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Description of Reference Numerals

[0033] 1 Energy storage module, 10 First energy storage cell, 11, 12 Ends, 20 Second energy storage cell, 21, 22 Ends, 30 Case, 100 Wound electrode body, 110 Positive electrode plate, 111 Negative electrode plate, 112 Separator, S, S' Clearance, Z direction (axial direction).

Claims

Claim 1 A plurality of first power storage cells arranged such that their axial directions are substantially parallel to each other, At least one second power storage cell arranged so as to be surrounded by the plurality of first power storage cells, A case for housing the plurality of first power storage cells and the second power storage cell, and comprising: Each of the plurality of first power storage cells and the second power storage cell has a cylindrical shape, A power storage module in which the diameter of each of the plurality of first power storage cells is larger than the diameter of the second power storage cell.

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