A novel, single ion, comb-branch polymer electrolyte has been synthesised. This was prepared by copolymerizing a poly (ethylene odds methoxy) acrylate (1) with lithium 1,1,3-trifluorobutane sulfonate acrylate (15), to produce comb-branch copolymers (7) whose compositions were adjusted to give [O]/[Li+] values of 12/1, 15/1, 20/1, 14/1, and 28/1. The conductivities were measured as a function of temperature and compared with the corresponding homopolymer of (1), the copolymers of (1) with the non fluorinated sulfonate and the carboxylate analogues of (15). The highest values of sigma were obtained for sample (7) when compared with the other two copolymer analogues (10) and (11), Glass transition temperatures (Tg) were measured for all samples as a function of the concentration of added salt and copolymers (7) exhibited the lowest Tgs. These new fluorinated, single ion, copolymers give remarkably good conductivity levels demonstrating the effective electron withdrawing properties of the fluorines which provides a facile release of the Li+ ion for conduction.