Energy storage device, energy storage apparatus, vehicle, and method for using energy storage device

An energy storage device 10 comprises a positive electrode 410, a negative electrode 420, and a separator 430 arranged between the positive electrode 410 and the negative electrode 420, wherein the negative electrode 420 has a negative substrate layer 421, and a negative composite layer 422 arranged on the surface of the negative substrate layer 421, the separator 430 has a separator substrate layer 431, the negative composite layer 422 contains a non-graphitizable carbon having a particle diameter D50 of 2.0 µm or more and 6.0 µm or less as a negative active material, and a corrected negative electrode density, which is defined as a value obtained by dividing, by a thickness of the separator substrate layer 431, a value obtained by multiplying a density of the negative composite layer 422 by a thickness of the negative composite layer 422, is 1.2 (g/cm) or more and 5.1 (g/cm) or less.