Driven by the fast-growing demand for high energy density and safety of Li-ion batteries, a number of efforts have been applied on developing Li-ion conducting solid electrolyte. Polymer electrolyte with its unique flexibility and low-cost has been regarded as one of the promising candidates. However, the performance of the conventional lithium ion polymer electrolyte is greatly limited due to the low transference number of Li, which is the active species in battery cycling. Gradient concentration of Li⁺ exists in a conventional Li-ion battery cell, resulting in polarization and impedance from concentration gradients. In this work, a single-ion conducting polymer electrolyte is prepared via an efficient thiol-ene reaction initiated by UV light. A high unity Li transference number of 0.91 is achieved by anchoring anions onto the polymer network. The polymer electrolyte exhibited an ionic conductivity of 10^-4 S/cm at 35 ºC. Utilized in a Li//LFP cell set-up, the cells with single-ion conducting electrolyte delivered a promising averaged coulombic efficiency of 99.95% for 175 cycles.