Metal sulfide nano-frameworks anchored into 3D honeycomb-like porous carbon nanofibers as freestanding anodes for high performance lithium-ion batteries

Abstract

Exploring advanced electrode materials with high lithium storage capacity and long cycling stability is of great importance for further development of lithium-ion batteries (LIBs). Herein, metal sulfide nano-frameworks anchored into 3D honeycomb-like porous carbon nanofibers are well designed and fabricated by electro-blowing spinning method and subsequent carbonization process. The effects of Ni/Co ratios on the nano-frameworks particle size, specific surface area and pore size distribution of fibers are systematically studied. Noticeably, the obtained fibers are crosslinked with each other to form a network film using as freestanding anode of LIBs, which avoids the cumbersome slurry-casting process. Moreover, the porous metal sulfide nano-frameworks meet the demand of high capacity while offering abundant cavities to accommodate volume expansion. More importantly, the 3D honeycomb-like porous carbon nanofibers as an ideal matrix not only provide enough buffer zones to alleviate volume expansion, but also shorten the diffusion pathways of electrons/ions. Benefiting from the advantages of structural feature, the optimized freestanding anode delivers an excellent lithium storage performance, including a high reversible capacity of 736 mAh g−1 after 200 cycles at 0.2 A g−1 and a long cycling stability of 73.5% capacity retention after 500 cycles at 1 A g−1.