Construction of Sb2Se3 nanocrystals on Cu2−xSe@C nanosheets for high performance lithium storage

Abstract

Copper selenide as an anode for lithium-ion batteries suffers from volume expansion/contraction, while constructing nanostructured copper selenide with other components is considered as an effective strategy. In this work, Cu_2−xSe@C@Sb₂Se₃ nanosheets were fabricated through a two step solvothermal procedure with the assistance of glucose. Such a structure can facilitate the migration rate of Li⁺, enhance the electrical conductivity, buffer the volume variation and prohibit the aggregation of the electrode. As a result, Cu_2−xSe@C@Sb₂Se₃ exhibits good electrochemical performance with a specific capacity of 341 mA h g⁻¹ after 100 cycles at a current density of 100 mA g⁻¹ and 153 mA h g⁻¹ at a rate of 2000 mA g⁻¹. Such a structural design and synthetic strategy may also be applied to explore other nanocomposites to improve the electrochemical performance.