Graphitic nanostructure integrated NiO composites for high-performance lithium-ion batteries.

Abstract

So far, various graphite-Nickel Oxide (NiO) composites have been investigated as anodes for Li-ion batteries. However, developing an ideal composite that overcomes NiO's electrical conductivity limitations remains a significant challenge. The current study presents an in-situ one-step hydrothermal technique for integrating NiO into a 3D peony-like graphitic nanostructure (NiO-GNF), resulting in unique thin nanosheet arrays with porous, conductive channels. Notably, the composites endowed controlled aggregation and restacking of NiO, buffered electrode stress and improved electrical conductivity due to the expanded nature of graphite. In addition, the enlarged interlayer spacing of expanded graphite facilitated an improved Li-ion insertion. Overall, in comparison to pure NiO anodes, the NiO-GNF composite achieved an impressive electrochemical improvement exhibiting a highly reversible discharge capacity of 678.2 mAh/g after 370 cycles at a current density of 0.5 A g−1, corresponding to a capacity retention of 60.7 %. The composite also demonstrated a capacity of 752 mAh/g at a high current density of 1.2 A g−1.