NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

In a nonaqueous electrolyte secondary battery, a separator includes a substrate, a first filler layer disposed on one side of the substrate and containing phosphate salt particles, and a second filler layer disposed on the other side of the substrate and containing inorganic particles. The separator is disposed between a positive electrode and a negative electrode in such a manner that the side of the substrate which bears the first filler layer is directed to the positive electrode side.