A single-ion polymer electrolyte has formula (I): R—[SO2N(M)SO2—X—]m—SO3Li (I). In formula (I), X may be an electron withdrawing group such as an aromatic group, substituted aromatic group, —(CF2)n—, —(CCl2)n—, —C6H4—, or —C6H3(NO2)—. R may be a fluorinated alkyl, LiSO3(CF2)3—, or an aromatic group, and M may be a metal cation. For the single-ion polymer electrolyte with formula (I), m may be an integer from 2 to 2000, and n may be an integer from 1 to 4.