Crystallographic structure and electrical properties of LiF modified Li29Zr9Nb3O40 for electrolyte of solid-state batteries

Lithium-ion batteries (LIBs) based on solid-state electrolytes have attracted much attention for their high safety and energy density. Li29Zr9Nb3O40 (LZNO), as a new kind of Li-ion conductor, has great potential in applications of solid-state LIBs. In this work, various contents of LiF are selected to modify LZNO Li-ion conductor, and the optimal content of LiF is 5 wt% (weight%). The phase component, crystal structure, ionic conductivity, and electrochemical performance are investigated. The refinement of crystallographic information based on the bond valence site energy theory is induced to reveal the possible lithium-ion migration channel. The results show that modification with LiF enhanced the 3D migration pathways and conductivity of LZNO-based electrolytes. The 5 wt% LiF modified LZNO presents total conductivity of 0.943 × 10−4 S cm−1 at ambient temperature and has low activation energy of conduction (0.16 eV). The cycle performance of the lithium symmetric cell characterizes the cycle of 140 h.