Rechargeable batteries and battery packs

Abstract

Provided is a highly reliable secondary battery. An electrode wound body is formed by winding a laminated body, which includes a first electrode, a first separator, a second electrode, and a second separator, about a center axis extending in the height direction, and has an upper end surface and a lower end surface opposite to each other in the height direction and a lateral surface that connects the upper and lower end surfaces. An upper insulating member covers an upper-side surface portion at the upper-end-surface side of the lateral surface of the electrode wound body. A lower insulating member covers a lower-side surface portion at the lower-end-surface side of the lateral surface of the electrode wound body. A battery can has: a container having a lower end closed by a bottom portion and having an upper end that is positioned on a side opposite to the lower end in the height direction and that includes an opening opened to allow the electrode wound body to be inserted therethrough; and a lid that covers the opening of the container. The battery can stores the electrode wound body. The tensile strength of the upper insulating member is 1.80 mN / mm or higher, and the tensile strength of the lower insulating member is 0.38 mN / mm or higher.

Claims

1. An electrode winding body comprising a laminate including a first electrode, a first separator, a second electrode, and a second separator, wound around a central axis extending in the height direction, having upper and lower end faces facing each other in the height direction, and a side surface connecting the upper and lower end faces, An upper insulating member that covers the upper side portion of the side surface of the electrode winding body on the upper end surface side, A lower insulating member that covers the lower side portion of the side surface of the electrode winding body on the lower end face side, A first electrode current collector plate, which is connected to the first electrode while facing the upper end face of the electrode winding body, A second electrode current collector plate, which is connected to the second electrode while facing the lower end face of the electrode winding body, A container having a lower end closed by a bottom and an upper end located on the opposite side of the lower end in the height direction and including an opening through which the electrode winding can be inserted, and a battery can having a lid that closes the opening of the container, and containing the upper insulating member, the lower insulating member, the first electrode current collector plate, the second electrode current collector plate, and the electrode winding, Equipped with, The first electrode has a first electrode covering portion in which the first electrode current collector is covered with a first electrode active material layer, and a first electrode exposed portion in which the first electrode current collector is exposed without being covered with the first electrode active material layer and is joined to the first electrode current collector plate. Multiple first edges of the first electrode exposed portion wound around the central axis, which are adjacent in the radial direction of the electrode winding body, are bent toward the central axis so as to overlap each other and form the upper end face. The second electrode has a second electrode covering portion in which the second electrode current collector is covered with a second electrode active material layer, and a second electrode exposed portion in which the second electrode current collector is exposed without being covered with the second electrode active material layer and is joined to the second electrode current collector plate. Multiple second edges of the second electrode exposed portion wound around the central axis, which are adjacent in the radial direction of the electrode winding body, are bent toward the central axis so as to overlap each other and form the lower end face. The first electrode current collector plate and the first electrode current collector include a first metal material, The second electrode current collector plate and the second electrode current collector include a second metal material having electrical conductivity and thermal conductivity that are higher than, respectively, the electrical conductivity and thermal conductivity of the first metal material. The tensile strength of the upper insulating member is 1.80 mN / mm or more. The tensile strength of the lower insulating member is 0.38 mN / mm or more. Secondary battery.

2. The tensile strength of the upper insulating member is greater than the tensile strength of the lower insulating member. The secondary battery according to claim 1.

3. The thickness of the upper insulating member and the thickness of the lower insulating member are, respectively, 9 μm or more and 16 μm or less. The secondary battery according to claim 1.

4. The upper insulating member and the lower insulating member each contain at least one of PP (polypropylene) and PI (polyimide). The secondary battery according to claim 1.

5. The upper insulating member also covers a portion of the upper end face. The secondary battery according to claim 1.

6. The lower insulating member also covers a portion of the lower end surface. The secondary battery according to claim 1.

7. The first electrode is a positive electrode, and the second electrode is a negative electrode. The secondary battery according to claim 1.

8. The first metal material is aluminum or an aluminum alloy, The second metallic material is nickel, a nickel alloy, copper, or a copper alloy. The secondary battery according to claim 1.

9. A secondary battery according to any one of claims 1 to 8, A control unit for controlling the secondary battery, The outer casing enclosing the aforementioned secondary battery and A battery pack that has [a certain feature].

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