Controlled synthesis of copper telluride nanostructures for long-cycling anodes in lithium ion batteries

Abstract

Copper telluride nanocubes, nanosheets, and nanoparticles were prepared by a solvothermal method under the protection of an inert atmosphere. The influence of reaction parameters, including precursor concentration, precursor ratio, precursor type, reaction time, reaction temperature, solvent, and organic ligands, on the size, morphology, crystalline structure, and composition of the resultant copper telluride nanostructures was comprehensively investigated. The results showed that the crystal structure and composition of the resultant nanostructures varied case by case, demonstrating the complexity of copper tellurides, despite their simple molecular formula. The obtained copper telluride nanostructures were tested as anodes in lithium ion batteries. The assembled Li/LiPF₆/Cu_xTe cells exhibit extremely high cycling stability (up to 5000 cycles) and their highest specific capacity is 280 mA h g⁻¹. The results also showed better performance of the Cu_2−xTe nanosheet electrodes than those of electrodes made from nanoparticles and nanocubes, demonstrating the importance of controlling the morphology of copper telluride during preparation.