A polymer for an electrode protective layer including a polymer (A) including a fluorine-based polymer in which a monomer unit including poly(alkylene oxide) and a monomer unit including a curable functional group (e.g., a thermocurable functional group or a photocurable functional group) are grafted on the fluorine-based polymer, and when preparing an electrode by coating an electrode active material layer using the polymer and curing (e.g., thermally curing or photocuring) the result, excellent lithium ion conductivity is obtained since lithium ion flow is not inhibited, chemical resistance for an electrolyte liquid is high, and voltage stability of a secondary battery may be enhanced by suppressing side reactions with the electrolyte liquid occurring on an electrode active material surface due to properties of a uniform and flexible protective layer.