Sustainable Low-Temperature Coating of LATP/C Solid Electrolyte Composites on LiNi_1/3Co_1/3Mn_1/3O₂ Cathode Based on Lithium Iodide Solvent-Recrystallization for Li-Ion Batteries

Abstract

A mixed ionic (Li1.3Al0.3Ti1.7(PO4)3: LATP) and electronic conductor (porous carbon: C) hybrid layer can effectively enhance the electrochemical performance of cathode materials. In this work, a sustainable low-temperature synthesis strategy (≤ 200℃) combining ball milling and solvent-recrystallization of lithium iodide is proposed to prepare the LATP/C coated LiNi1/3Co1/3Mn1/3O2 (LNCMO) material. The characterizations of structures and morphology reveal that LATP and porous carbon powder are mixed into the ethanol dissolved lithium iodide by a simple ball milling process, then the lithium iodide is recrystallized to serve as a binder when ethanol is vaporized at a low temperature to coat uniform thickness and homogeneously distributed LATP/C on the surface of LNCMO cathode. The charge-discharge results illustrate that the cycling performance and rate discharge capability of the active materials coated with LATP/C are significantly superior to the bare LNCMO. AC impedance analysis confirms that lower charge transfer resistance and higher Li+ ion diffusion coefficient are achieved in cathode materials. This work successfully exploited a novel low-temperature cathode coating method based on lithium iodide solvent-recrystallization and obtained results comparable to high-temperature processes without suffering from side reaction problems.