Flame-Spray-Pyrolyzed Ultrafine Li ₄ Ti ₅ O ₁₂ Nanochains Enable Multilayer Coatings for a Stable Interface of Nickel-Rich Cathodes in Long-Life Lithium-Ion Batteries

The nickel-rich cathode materials LiNi0.83Co0.11Mn0.06O2(NCM83) supply a high energy density for lithium-ion batteries (LIBs). However, the electrolyte would corrode cathode materials during the cycling process, leading to structural degradation of the cathode materials. Although surface coating with metal oxides could alleviate these issues, there is always a contradiction between the coating effect and ion transport. Here, we report an NCM83 cathode material with Li4Ti5O12 (LTO) nanochain coatings, in which the ultrafine LTO nanochains were synthesized by flame spray pyrolysis (FSP), with the primary particle size ranging from approximately 8–12 nm. These nanochains, with high specific surface area and low fractal dimension, can form efficient multilayer coatings on the surface of NCM83. Due to their high ion conductivity, the LTO coatings exhibited superior ion transport compared to electrochemically inert metal oxides such as TiO2. Additionally, LTO coatings established a stable interface between the cathode materials and the electrolyte. In comparison with the primary NCM83 and TiO2-coated samples, the LTO-coated samples demonstrated enhanced cycling and rate performance, realized a slighter interface reaction, and more superior structural maintenance. The capacity retention of the assembled LTO-NCM83/graphite full cell exhibited 82.33% at 0.5 C after 1300 cycles, providing superior performance and durability.