[Problems] Objects include providing a pressure sensitive adhesive sheet for batteries that is excellent in the insulation properties even after heated to high temperatures and also excellent in the insulation properties even when immersed in an electrolyte solution for a long time and then heated to high temperatures and also providing a lithium-ion battery in which the pressure sensitive adhesive sheet for batteries is used.[Solution] A pressure sensitive adhesive sheet for batteries (1), comprising: a base material (11); a hard coat layer (12) provided at one side of the base material (11); and a pressure sensitive adhesive layer (13) provided at a side of the hard coat layer (13) opposite to the base material (11), the hard coat layer (12) being formed of a composition for hard coat layer that contains a metal oxide sol, the metal oxide sol being a sol of a metal oxide that has insulation properties.