| 摘要 |
A lithium-ion secondary battery of the present invention contains: a laminated electrode group formed of a rectangular positive electrode; a rectangular negative electrode; and a separator. In such a laminated electrode group, the positive electrode includes a positive electrode current collector foil, and a positive electrode mixture layer containing a positive electrode active material, the negative electrode includes a negative electrode current collector foil, and a negative electrode mixture layer containing a negative electrode active material. The negative electrode active material includes a silicon-based material, and a carbonaceous material. A mass ratio of the silicon-based material and the carbonaceous material is 20:80 to 80:20. The silicon-based material is a Si alloy or SiOx (0.5≦x≦1.5). The positive electrode and the negative electrode have a collection terminal protruding from a same side of the laminated electrode group. The negative electrode current collector foil is formed of any one of a stainless steel; a copper alloy containing a copper with a purity of 99.9% or more, and one or more kinds of elements selected from the group consisting of zirconium, silver and tin; and a copper with a purity of 99.99% or more. When a comparison are drawn between lengths of the positive electrode mixture layer and the negative electrode mixture layer in a direction where the collection terminal protrudes from the same side, the length of the positive electrode mixture layer is the length of the negative electrode mixture layer or longer. Thus, a short circuit in charging and discharging of the lithium-ion secondary battery can be suppressed. |
| 主权项 |
1. A lithium-ion secondary battery comprising:
a rectangular positive electrode; a rectangular negative electrode; and a separator, wherein the positive electrode, the negative electrode, and the separator constitute a laminated electrode group, the separator is coated on one or more sides with an inorganic filler containing at least SiO2, Al2O3, montmorillonite, mica, SnO, TiO2, BaTiO3, and ZrO2, the positive electrode includes a positive electrode current collector foil, and a positive electrode mixture layer containing a positive electrode active material, the negative electrode includes a negative electrode current collector foil, and a negative electrode mixture layer containing a negative electrode active material, the negative electrode active material includes a silicon-based material, and a carbonaceous material, the negative electrode includes a binder comprising one or more of the following: polyamideimide, polyimide, polyamide, PVDF, or SBR, a mass ratio of the silicon-based material and the carbonaceous material is 20:80 to 69:31, the silicon-based material is a Si alloy or SiOx (0.5≦x≦1.5), the positive electrode and the negative electrode have a collection terminal protruding from a same side of the laminated electrode group, the negative electrode current collector foil is formed of any one of a stainless steel; a copper alloy containing copper with a purity of 99.9% or more and one or more kinds of elements selected from the group consisting of zirconium, silver and tin; and when comparisons are drawn between lengths of the positive electrode mixture layer and the negative electrode mixture layer in a direction where the collection terminal protrudes from the same side, the length of the positive electrode mixture layer is the length of the negative electrode mixture layer or longer. |
