| 摘要 |
The present invention provides a nonaqueous electrolyte secondary cell of high capacity, with improved cycle life. The nonaqueous electrolyte secondary cell is equipped with: a wound electrode group of a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; and a nonaqueous electrolyte. The volume energy density is 650 Wh/L or above. The positive electrode includes a positive electrode current collector, and a positive electrode mixture layer deposited over the surface of the positive electrode current collector, while the negative electrode includes a negative electrode current collector, and a negative electrode mixture layer deposited over the surface of the negative electrode current collector. The porosity Pp of the positive electrode mixture layer is 22% or less, and the porosity Pn of the negative electrode mixture layer is 25% or less. The ratio VE/VT of the nonaqueous electrolyte volume VE to the total VT of the positive electrode mixture layer pore volume, the negative electrode mixture layer pore volume, and the separator pore volume is 1-1.5 inclusive, and the difference between the positive electrode contact angle CAp and the negative electrode contact angle CAn with respect to the nonaqueous electrolyte is 23º or less. |
