NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

Provided is a non-aqueous electrolyte secondary battery having a high capacity and an improved cycle life. The battery includes an electrode group and a non-aqueous electrolyte, and has a volume energy density of 650 Wh/L or more. The electrode group includes wound positive and negative electrodes with a separator interposed therebetween. The positive and negative electrodes each include a current collector and a material mixture layer adhering thereto. The positive and negative electrode material mixture layers each have a porosity Pp of 22% or less and porosity Pn of 25% or less. The ratio VE/VT of a volume VE of the electrolyte to a total VT of the pore volumes of the positive and negative electrode material mixture layers, and the separator is 1 to 1.5. The difference between contact angles CAp and CAn of the positive and negative electrodes with respect to the non-aqueous electrolyte is 23° or less.

主权项

1. A non-aqueous electrolyte secondary battery comprising: an electrode group including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, the positive electrode, the negative electrode, and the separator being wound together; and a non-aqueous electrolyte, and
having a volume energy density of 650 Wh/L or more, the positive electrode including a positive electrode current collector, and a positive electrode material mixture layer adhering to a surface of the positive electrode current collector; the negative electrode including a negative electrode current collector, and a negative electrode material mixture layer adhering to a surface of the negative electrode current collector; the positive electrode material mixture layer having a porosity Pp of 22% or less, and the negative electrode material mixture layer having a porosity Pn of 25% or less; a ratio VE/VT of a volume VE of the non-aqueous electrolyte to a total VT of a pore volume of the positive electrode material mixture layer, a pore volume of the negative electrode material mixture layer, and a pore volume of the separator being 1 or more and 1.5 or less; and a difference between a contact angle CAp of the positive electrode and a contact angle CAn of the negative electrode with respect to the non-aqueous electrolyte being 23° or less.