Cholesteric Liquid Crystal Elastomer-Based Single-Ion Conductor for Advanced Quasi-Solid Electrolyte Membranes

Self-assembled liquid crystal polymer networks build directional transport channels via molecular alignment, enabling efficient and ordered lithium-ion migration, while single-ion conducting polymer electrolytes improve lithium-ion transference number by covalently anchoring anions, which alleviates concentration polarization and effectively suppresses lithium dendrite growth. Herein, a series of substrate-free Li salt-grafted cholesteric liquid crystal elastomers (CLCE) with tunable helical pitches and spiral orientation were fabricated, and quasi-solid electrolyte membranes were obtained through plasticization. It was found that samples with the smallest helical pitch delivered the highest lithium-ion transference number irrespective of the spiral orientation. The optimal CLCE electrolyte membrane achieved a lithium-ion transference number of 0.94, exhibiting characteristic single-ion conductivity. Moreover, after adding small amount of extra free Li salt, the prepared electrolyte membrane delivered a room-temperature ionic conductivity of 2.6 × 10−4 S·cm−1, an electrochemical stability window of 5.2 V and stable cycling performance, providing new insights into the design of high-performance safe quasi-solid lithium-ion batteries.