Simple hydrothermal synthesis of HCNFs@CoNiO 2 composite material for high-performance anode of lithium-ion batteries

In this study, a novel helical carbon nanofibers@CoNiO 2 (HCNFs@CoNiO 2 ) composite was first successfully synthesized by the simple hydrothermal method and utilized as anode materials of lithium -ion batteries (LIBs). CoNiO 2 nanoparticles with a particle size of about 6 nm were distributed on the surface of HCNFs matrix. The HCNFs@CoNiO 2 anode shows the excellent reversible specific capacity of 808.5 mAh/g after 100 cycles at 200 mA/g, which is about four and twenty times larger than that of HCNFs (193.5 mAh/g) and CoNiO 2 (35.4 mAh/ g), respectively. The electrochemical performance of HCNFs@CoNiO 2 was improved due to the synergistic contribution of HCNFs and CoNiO 2 . In particular, HCNFs with the unique three-dimensional helical structure improve the conductivity and also provide a strong supporting network space during the volume expansion of CoNiO 2 nanoparticles. The present study provides a useful reference for the development of the novel highperformance anode material for LIBs.