One-step fabrication of in situ carbon-coated NiCo2O4@C bilayered hybrid nanostructural arrays as free-standing anode for high-performance lithium-ion batteries.

Rapid developments in revolutionary electric vehicles have led to an increase in the energy-density and cycling-life requirements for Li-ion batteries (LIBs). The binary transition metal oxide NiCo 2 O 4 is attracting considerable attention due to its much larger specific capacity than graphite. However, NiCo 2 O 4 suffers from poor cycling performance owing to a large volume change during cycling. To address this problem, we proposed an easy strategy to fabricate in situ carbon-coated NiCo 2 O 4 bilayered hybrid nanostructural arrays supported on Ni foam (denoted as NiCo 2 O 4 @C BHNAs–NF) as free-standing anodes for LIBs through a sucrose-assisted hydrothermal method. The in situ-synthesized uniform carbon shell can simultaneously buffer the volume change during cycling and increase the conductivity. The micro/nano-structure also possessed outstanding structural advantages, such as large surface area and hierarchical porous characters, enabling NiCo 2 O 4 @C BHNAs–NF to have excellent electrochemical performance. Its capacity can reach 1298 mAh/g at a current density of 100 mA/g, and 86% of the initial capacity can be retained after 100 cycles. All these results revealed that NiCo 2 O 4 @C BHNAs–NF was a promising candidate anode for next-generation LIBs. [ABSTRACT FROM AUTHOR]