SEPARATOR, NON-AQUEOUS ELECTROLYTE SECONDARY CELL INCLUDING THE SAME, AND ASSEMBLED BATTERY

The separator disclosed herein includes a substrate and an adhesive layer. The adhesive layer is partially provided on one side of, or both of two sides of, the substrate. Where an initial thickness of the separator is T0, a thickness of the separator when the separator is impregnated with an electrolyte solution and supplied with a pressure of 1 MPa is T1, a thickness of the separator when, after this, the separator is supplied with a pressure of 2 MPa for 1 hour, and the pressure is decreased to 0.5 MPa, is T2, and a thickness of the separator when, after this, the separator is supplied with a pressure of 4 MPa for 48 hours, is T4, the separator satisfies inequalities (1) through (3): (1) 1≤T1/T0≤1.1; (2) 0.92≤T2/T1≤1; and (3) 0.6≤T4/T1≤0.8.