Hexagonal liquid crystals as emerging quasi solid-state electrolytes for aqueous lithium-ion batteries

Abstract

The increasing market demand ranging from portable electronics to electric vehicles drives the advancement of lithium-ion batteries. However, traditional liquid electrolytes used in LIBs are plagued by issues such as leakage, vaporization, and the degradation of active materials, which compromise performance and pose safety risks. To address these challenges, herein, the liquid-crystalline electrolytes with hexagonal phase were designed based on the self-assembly of amphiphilic molecules, which exhibit both high ionic conductivity and a high Li⁺ transference number. The hexagonal liquid crystal structure reconfigures the Li⁺ solvation structure and provides a transport pathway for the Li⁺ structural diffusion, facilitating the efficient transport of Li⁺ and contributing to the high ionic conductivity. Furthermore, the ordered arrangement of amphiphilic anion significantly restricts anion diffusion, resulting in an exceptionally high Li⁺ transference number of 0.92. Additionally, when utilizing NaV₃O₈ (NVO) as the anode and LiMn₂O₄ (LMO) as the cathode, the resultant full cell delivers impressive rate performance and stable cycling performance. This work highlights the potential of lyotropic liquid crystals in the development of high-performance quasi solid-state electrolytes for aqueous lithium-ion batteries and beyond