Current collector for lithium ion secondary batteries and positive electrode for lithium ion secondary batteries
View Patent ↗A current collector for a lithium ion secondary battery, on which an electrode mixture layer is formed, satisfies A≥0.10 μm and 6≤(B/A)≤15 when assuming that a three-dimensional center plane average roughness SRa of a surface of at least one side of the current collector on which the electrode mixture layer is formed is A and a ratio of an actual surface area of the surface of at least one side of the current collector to a geometric area of the surface of at least one side of the current collector, which is (actual surface area)/(geometric area), is B.
1. A positive electrode current collector for a lithium ion secondary battery on which an electrode mixture layer is formed, wherein
when assuming that a three-dimensional center plane average roughness SRa of a surface of at least one side of the positive electrode current collector on which the electrode mixture layer is formed is A and a ratio of an actual surface area of the surface of at least one side of the positive electrode current collector to a geometric area of the surface of at least one side of the positive electrode current collector, which is (actual surface area)/(geometric area), is B, A≥0.10 μm and 6 μm −1 ≤(B/A)≤15 μm −1 are satisfied; and
the positive electrode current collector is made of an aluminum-based metal.
2. The positive electrode current collector for a lithium ion secondary battery according to claim 1 , wherein
the ratio B satisfies 1.2≤B≤4.5.
3. The positive electrode current collector for a lithium ion secondary battery according to claim 1 , wherein
the roughness A satisfies 0.10 μm≤A≤0.70 μm.
4. The positive electrode current collector for a lithium ion secondary battery according to claim 1 , wherein
the surface of the positive electrode current collector is formed by an electrolytic process.
5. A positive electrode for a lithium ion secondary battery comprising:
the positive electrode current collector for a lithium ion secondary battery according to claim 1 ; and
an electrode mixture layer including a positive electrode active material, an electroconductive material, and a binder, formed on the surface of the positive electrode current collector.
6. The positive electrode for a lithium ion secondary battery according to claim 5 , wherein
the positive electrode active material has an average primary particle size of 10 to 500 nm.