Mesoporous RGO/NiCo2O4@carbon composite nanofibers derived from metal-organic framework compounds for lithium storage

Volume expansion is one of the challenges of hindering the implementation of lithium-ion batteries (LIBs). In this respect, the RGO/NiCo2O4@carbon composite nanofibers (RGO/NCO@C) derived from metal-organic frameworks are developed by an effective in-situ growth, electrospinning and assisted procedure of calcination. The NiCo2O4 particles anchor on the carbon nanofibers that decorated with the graphene sheets to form a bead-like structure, which endows the anode material with large specific surface area (SSA), massive pore structures and desirable mechanical strength. Benefiting from above excellent physical properties, the composite nanofibers greatly relief the volume expansion and efficiently shorten the Li-ion diffusion path. As a result, superior cyclability and great rate capability are obtained upon using as anode material for lithium-ion batteries. An extremely high reversible charge capacity of 2048 mAh g-1 is achieved in the first cycle, and capacity retention of 1712 mAh g-1 is retained after 500 cycles at 0.3 A g-1. Under various current densities ranging from 0.3 to 2 A g-1, the reversible capacity of 1783 mAh g-1 at 0.3 A g-1 is sustained. The proposed method and developed materials herein offer an effective strategy to overcoming the volume expansion and preparing electrode materials for high performance LIBs.

Automated summary

The RGO/NCO@C composite nanofibers derived from metal-organic frameworks effectively address the challenge of volume expansion in lithium-ion batteries. The unique structure provides large specific surface area, pore structures, and mechanical strength, resulting in superior cyclability and rate capability as anode material.