Functional surface modifications on nanostructured LiCoO₂ with lithium vanadates

摘要

Novel surface modifications with lithium vanadate (Li₃VO₄) were performed on LiCoO₂ nanoparticles that were synthesized by a hydrothermal method. Facile wet coatings followed by high-temperature treatments were utilized to create the lithium vanadate layers. Reaction mechanisms between the surface modifier and LiCoO₂ nanoparticles were also systematically investigated. Upon thermal annealing, lithium vanadates often captured Li from LiCoO₂. It was found that it is crucial to add extra LiOH not to deteriorate LiCoO₂ during the high-temperature treatments. For small weight percentage coatings (5.5 wt%), thin layers of Li₃VO₄ were found on the surface of LiCoO₂; while for high weight percentage coatings (53.1 wt%), thick Li₃VO₄ shells as well as separate nanostructures were observed.