An Effective Method To Suppress Side Reactions and Enhance Li⁺ Diffusion Rate of LiNi_0.92Co_0.04Mn_0.04O₂ Cathode...

A high nickel content layered cathode material such as LiNi_0.92Co_0.04Mn_0.04O₂ (N92) is regarded as an extremely promising candidate for a next-generation high-energy-density lithium ion battery (LIB) owing to the large specific capacity and low cost. Nonetheless, some undesirable defects, including structure instability, large cation mixing between Ni²⁺ and Li⁺, and serious side reactions caused by high oxidation of Ni⁴⁺, have made this competitor difficult to put into a practical application. In the present work, the high speed mill-balling method is adopted to prompt the lithium superionic conductor Li_0.388Ta_0.238La_0.475Cl₃ (LTLC) cover on the surface of N92 particles to enhance the large rate and low-temperature discharge performance, maintain the cyclic stability, and strengthen the safety behaviors. As a result, the LTLC covering layer accompanied by La³⁺ and Ta⁵⁺ doping could not only suppress the side reactions and enhance the whole structure stability of a cathode but also contribute to improving the Li⁺ intercalation/deintercalation efficiency from the cathode material interface and accelerating the Li⁺ diffusion rate in the cathode bulk. Compared to N92, the cathode after 2% LTLC covering indeed demonstrates much better electrochemical properties and enhanced safety performance, which exhibits great practicality when applied in high-energy-density LIB.