| abstract |
A nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, a nonaqueous electrolyte, and a separator. The positive electrode includes a lithium composite oxide having an average composition represented by the following formula (1) n Li x Co y Ni z M 1-y-z O b-a X a (1) n The separator includes a base layer and a polymer resin layer provided on at least one primary surface of the base layer, and the polymer resin layer includes at least one of poly(vinylidene fluoride), poly(vinyl formal), poly(acrylic ester), and poly(methyl methacrylate). n In the above formula (1), M indicates at least one element selected of boron, magnesium, aluminum, silicon, phosphorous, sulfur, titanium, chromium, manganese, iron, copper, zinc, gallium, germanium, yttrium, zirconium, molybdenum, silver, strontium, cesium, barium, tungsten, indium, tin, lead, and antimony. X represents a halogen element. X, y, z, a, and b respectively satisfy 0.8<x≦1.2, 0≦y≦1.0, 0.5≦z≦1.0, 0≦a≦1.0, and 1.8≦b≦2.2. Also, y<z is satisfied. |