NONAQUEOUS ELECTROLYTE ELECTRICITY STORAGE ELEMENT AND METHOD FOR PRODUCING NONAQUEOUS ELECTROLYTE ELECTRICITY STORAGE ELEMENT

One aspect of the present invention is a nonaqueous electrolyte energy storage device including a positive electrode containing manganese-containing positive active material particles in which aluminum is present at least on a surface, and a nonaqueous electrolyte containing a salt represented by the following formula (1). Another aspect of the present invention is a method of producing a nonaqueous electrolyte energy storage device, including producing a positive electrode containing manganese-containing positive active material particles in which aluminum is present at least on a surface, and providing a nonaqueous electrolyte containing a salt represented by the following formula (1): wherein R is a hydrogen atom, a halogen atom, or an organic group, M is an alkali metal cation, an alkaline earth metal cation, or an onium cation. m is an integer equivalent to the number of valence of a cation represented by M. when m is 2 or more, a plurality of Rs are each independently as defined above.