Patent attributes
A battery according to the invention includes, as a separator, a first separator and a second separator having mutually different characteristics. The first separator and the second separator are disposed inside an electrode assembly in a state where the separators are not in contact with each other in a stacking direction of the electrode assembly. The first separator and the second separator have the following characteristic: when the battery is constructed including an electrode assembly formed by stacking the positive electrode, the first separator and the negative electrode, a resistance increase rate X=Delta X/Delta P satisfies X>0 (positive value), X being evaluated from a change amount Delta P of surface pressure applied in the stacking direction of the electrode assembly and a resistance increment Delta X of the battery upon application of the surface pressure change amount Delta P, and when the battery is constructed including an electrode assembly formed by stacking the positive electrode, the second separator and the negative electrode, a resistance increase rate Y=Delta Y/Delta P satisfies Y<0 (negative value), Y being evaluated from a change amount Delta P of surface pressure applied in the stacking direction of the electrode assembly and a resistance increment Delta Y of the battery upon application of the surface pressure change amount Delta P.
