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 energy storage device according to an aspect of the present invention includes: a winding type electrode assembly including a negative electrode containing a negative active material, a positive electrode, and a separator disposed between the positive electrode and the negative electrode; a case housing the electrode assembly; and a spacer disposed between the electrode assembly and an inner surface of the case in the case, wherein the separator includes a wet film, the negative active material is a carbonaceous material or lithium titanate, and the spacer is harder than the separator.

Abstract: Provided is a nonaqueous electrolyte secondary cell including: a case; an element housed in the case, including at least a positive electrode member, a negative electrode member and a separator; and an electrolyte solution poured into the case, wherein when in the state of the case being installed, in the direction perpendicular to the liquid surface of the electrolyte solution, the length between the highest position and the lowest position of the element is represented by L1 and the length between the liquid surface and the lowest position of the element is represented by L2, the ratio calculated with the formula L2/L1×100 is 10% or more and 100% or less.

Abstract: An electric storage device includes an electrode assembly, in which a positive electrode and a negative electrode in the shape of a sheet are wound with a separator sandwiched therebetween. The electrode assembly has a flat shape and includes a first flat portion and a second flat portion, which are opposed to each other, and a first curved portion and a second curved portion which connect end portions of the first and second flat portions together. One of the positive electrode and the negative electrode covers an inner-circumferential end portion of the other electrode and is disposed on an innermost circumference of the electrode assembly. An inner-circumferential end portion of the one of the electrodes causes an elastic force to act outwardly on the other electrode.

Abstract: Provided is a nonaqueous electrolyte secondary cell including: a case; an element housed in the case, including at least a positive electrode member, a negative electrode member and a separator; and an electrolyte solution poured into the case, wherein when in the state of the case being installed, in the direction perpendicular to the liquid surface of the electrolyte solution, the length between the highest position and the lowest position of the element is represented by L1 and the length between the liquid surface and the lowest position of the element is represented by L2, the ratio calculated with the formula L2/L1×100 is 10% or more and 100% or less.

Abstract: An electric storage device includes an electrode assembly, in which a positive electrode and a negative electrode in the shape of a sheet are wound with a separator sandwiched therebetween. The electrode assembly has a flat shape and includes a first flat portion and a second flat portion, which are opposed to each other, and a first curved portion and a second curved portion which connect end portions of the first and second flat portions together. One of the positive electrode and the negative electrode covers an inner-circumferential end portion of the other electrode and is disposed on an innermost circumference of the electrode assembly. An inner-circumferential end portion of the one of the electrodes causes an elastic force to act outwardly on the other electrode.