Hierarchical CuBi2O4 microspheres as lithium-ion battery anodes with superior high-temperature electrochemical performance

Abstract

In the present report, hierarchical CuBi₂O₄ microspheres are prepared through a hydrothermal route, and applied as anode materials for LIBs. The hierarchical CuBi₂O₄ microspheres of diameter 2.0–4.0 μm are assembled by crystalline tetragonal nanoparticles with a size of 50–60 nm. The electrochemical performance of the hierarchical CuBi₂O₄ microspheres shows strong temperature-dependence whereby higher temperatures evidently enhance the electrochemical performance. At an elevated temperature of 70 °C, a reversible capacity of 525.1 mA h g⁻¹ has been achieved after 500 cycles at a current density of 100 mA g⁻¹. Even after being cycled at a high current density of 6.4 A g⁻¹, the hierarchical CuBi₂O₄ microspheres are still able to deliver a capacity of 585 mA h g⁻¹ when the current density is set back to 100 mA g⁻¹. The superior high-temperature electrochemical performance of the hierarchical CuBi₂O₄ microspheres is ascribed to their hierarchical structure and outstanding thermostability.