LaF surface-modified LiCrMnO cathode material with improved high-temperature performances for lithium-ion batteries.

The LaF surface-modified LiCrMnO samples were synthesized by co-precipitation method and characterized by high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray detector (EDX). HAADF-STEM and EDX observations showed that LaF deposited on the surface of LiCrMnO particles. When tested as the cathode materials for lithium-ion battery, the LaF-modified LiCrMnO exhibited significantly improved cyclic and rate performances at high temperature (55 °C). Electrochemical impedance spectrum analyses demonstrated that the surface of LiCrMnO modified by LaF was much more stable during the electrochemical process and could greatly facilitate the charge-transfer reaction, which may be attributed to the protection of active material by LaF from the HF attack. [ABSTRACT FROM AUTHOR]