Abstract: A nonaqueous electrolyte energy storage device according to an aspect of the present invention includes: a negative electrode including a negative composite layer containing a negative active material; a positive electrode; and a nonaqueous electrolyte containing a nonaqueous solvent, in which the nonaqueous solvent contains diethyl carbonate, the negative composite layer contains a nonaqueous binder, the negative active material contains non-graphitizable carbon; and an amount of charge B [mAh/g] of the negative electrode in a full charge state satisfies the following Formula 1 when a true density of non-graphitizable carbon is A [g/cm3].

Abstract: An energy storage device according to one aspect of the present invention is an energy storage device including a negative electrode having a negative electrode substrate and a negative active material layer stacked on the negative electrode substrate directly or via another layer, and a nonaqueous electrolyte solution, in which the negative active material layer contains graphite and a solvent-based binder, and the negative active material layer is not subjected to pressing.