A polymer, an electrolyte, and a lithium-ion battery employing the same are provided. The polymer is a product of a composition via a polymerization. The composition includes a first monomer and a second monomer. The first monomer has a structure represented by Formula (I) and the second monomer is fluorine-containing acrylate, fluorine-containing alkene, fluorine-containing epoxide, or a combination thereof. Particularly, n, m, and l are independently 1, 2, 3, 4, 5, or 6; and, R1, R2, R3, R4, R5 and R6 are as defined in the specification.