An electrochemical device including: an anode, a cathode, an electrolyte, and a separator separating the anode from the cathode. The separator includes a material that includes at least one of: a linear polymer; a kinetic friction coefficient of up to 2.0; an elongation of at least 240, elongation defined as elongation at break; a ratio of elongation to thickness of at least 10; and/or a modulus of elasticity of up to 270 MPa.