Self-assembly of porous CuO nanospheres decorated on reduced graphene oxide with enhanced lithium storage performance

Abstract

This work aims at enhancing the cycling stability and rate capability of a CuO-based anode material for lithium-ion batteries. Here porous CuO nanospheres decorated on reduced graphene oxide (CuO-NSs/RGO) have been synthesized by a two-step thermal treatment procedure. The porous CuO nanospheres are assembled by ultra-fine nanoparticles of CuO with a size of ∼15 nm. Such a porous nature endows many merits, improving the lithium storage performances of the CuO-NSs/RGO composite used as a lithium-ion battery anode. The porous CuO-NSs/RGO composite demonstrates superior reversible capacity (753.3 mA h g⁻¹ at 100 mA g⁻¹) and good cycling stability (616.2 mA h g⁻¹ after 200 cycles at 500 mA g⁻¹). In particular, it exhibits an outstanding high-rate capability of 327.3 mA h g⁻¹ even at 5 A g⁻¹. The feasibility of the CuO-NSs/RGO composite as an anode material was further investigated with a commercial LiFePO₄ (LFP) cathode for lithium-ion batteries.