Optimizing lithium-ion diffusion pathways in LaCl3-based solid electrolytes through cation vacancy modulation

Abstract

This study introduces controlled lanthanum-site cation vacancies while maintaining a fixed In : La molar ratio of 1 : 2 and adjusted the LiCl content to increase the Li⁺ concentration, successfully constructing a three-dimensional (3D) lithium-ion diffusion network. This approach effectively overcomes the limitations of the original 1D channels. Experimental results demonstrate that the optimized Li_3.6La_3.2In_1.6Cl₁₈ sample exhibits an exceptional lithium-ion conductivity of 0.17 mS cm⁻¹ at 30 °C, coupled with a low migration activation energy of 0.484 eV.