Harnessing Anisotropy in Liquid Crystal Elastomer based Solid-State Batteries

Lithium-ion batteries (LIBs) are the backbone of modern portable electronics. However, most of them use liquid electrolytes containing flammable, volatile organic solvents which pose safety concerns. Recently we showed the potential of lithium-ion doped nematic Liquid Crystal Elastomer (LCE)-based solid polymer electrolytes for batteries demonstrating excellent charge-discharge capacities. In this work, we report the first investigation of homeotropically aligned LCEs in lithium-ion batteries and systematically compare their performance with planar alignment. We demonstrate that with increased ionic liquid (IL) loading, the homeotropic alignment (director is perpendicular to the electrodes) exhibits higher conductivity compared to planar alignment (director is parallel to the electrodes), underscoring the tunability of LCE-based electrolytes. The samples with the highest IL loading in both alignments exhibit a room temperature conductivity of ~1 and an electrochemical stability window of ~4.8 V. Additionally we find that LCE based batteries with homeotropic alignment charge more rapidly. These findings provide new insights into optimizing electrolyte performance through liquid crystal alignment control, thereby advancing the development of solid-state lithium-ion batteries.