NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

A non-aqueous electrolyte secondary battery including a positive electrode, a negative electrode, and a non-aqueous electrolyte, in which the positive electrode includes a positive electrode active material, the positive electrode active material includes a lithium-transition metal composite oxide containing Ni, Mn, and Al, proportions of Ni, Mn, and Al in metal elements other than Li contained in the lithium-transition metal composite oxide are, respectively, Ni: 50 atm % or more, Mn: 10 atm % or less, and Al: 10 atm % or less, when the lithium-transition metal composite oxide contains Co, a content of Co in the metal elements other than Li is 1.5 atm % or less, and the non-aqueous electrolyte includes a fluorosulfonic acid salt.