A method of forming a button-type battery includes: a) positioning first and second terminal housing members in facing juxtaposition to one another, and providing an anode, a cathode and an electrolyte intermediate the first and second terminal housing member central portions; b) providing a peripheral insulative sealing gasket intermediate the first and second terminal housing members, the insulative sealing gasket being in the shape of an annulus and having a radial extent which extends radially outward beyond the surrounding peripheral portions of the first and second terminal housing members; c) moving at least one of the juxtaposed first and second terminal housing members in the direction of the other to push the first terminal housing member container wall against the first gasket face and to simultaneously force the second terminal housing member peripheral portion against the second gasket face, and continuing such moving to bend the insulative gasket about the container wall and force it to be received within the first terminal housing member; and d) after the moving step, crimping the container wall and sealing gasket against the peripheral portion of the second terminal housing member to form an enclosed housing. An alternate method includes: i) providing a discrete, pre-formed peripheral insulative sealing gasket in the shape of an annulus; and ii) positioning the discrete, pre-formed sealing gasket within the first terminal housing member, then crimping to seal. A novel gasket construction is also disclosed.