Abstract: An energy storage device according to an aspect of the present invention includes: an electrode assembly in which a positive electrode and a negative electrode are stacked with a separator interposed therebetween; an electrolyte solution; and a sealable case for housing the electrode assembly and the electrolyte solution, in which a compressive modulus of elasticity of the separator is 15 MPa or more and an inside of the case is in a negative pressure state.

Abstract: An aspect of the present invention is an electrode for an energy storage device including a conductive substrate, an intermediate layer, and an active material layer in this order. In this electrode, the intermediate layer includes a conductive agent, an inorganic oxide, and a binder, and the content of the inorganic oxide in the intermediate layer is 30% by mass or more and 90% by mass or less.