Abstract: An electrode according to one aspect of the present invention is an electrode for an energy storage device, including an active material layer containing an active material, fibrous carbon, a binder mainly containing an acrylic resin, and a polysaccharide polymer, in which the content ratio of the polysaccharide polymer to the acrylic resin on a mass basis is 0.01 or more and 0.40 or less.

Abstract: An aspect of the present invention is a nonaqueous electrolyte energy storage device including: a negative electrode including a negative active material layer with a thickness expansion rate of 10% or more due to charge; and a separator, in which the absolute value (|dR/dP|) of an increase in resistance (dR) to a change in pressure (dP) in pressurization is 0.15 ?·cm2/MPa or less in the separator impregnated with a measurement electrolyte solution, the measurement electrolyte solution contains an ethylene carbonate and an ethyl methyl carbonate as a solvent, and a lithium hexafluorophosphate as an electrolyte salt, the volume ratio between the ethylene carbonate and the ethyl methyl carbonate is 30:70, and the concentration of the lithium hexafluorophosphate is 1.0 mol/L.

Abstract: One aspect of the present invention is a nonaqueous electrolyte energy storage device including: a positive electrode; and a negative electrode containing silicon oxide, wherein an initial irreversible capacity of the positive electrode to an initial irreversible capacity of the negative electrode is 1.15 or more.