Boosting lithium-ion storage performance by synergistically coupling Zn0.76Co0.24S with N-/S-doped carbon and carbon nanofiber

Abstract

In this work, we combine the preparation approach of bimetal-organic-framework and electrospinning technique to obtain Zn0.76Co0.24S nanoclusters with N-/S-doped carbon overlayer embedded in the interconnected one-dimensional (1D) carbon fibers (Zn0.76Co0.24S@C@CNF). Benefiting from the synergistic effect among Zn0.76Co0.24S, N-/S-doped carbon overlayer and carbon nanofiber, the Zn0.76Co0.24S@C@CNF anode exhibits large reversible capacities of 1113 mAh g−1 after 250 cycles at 0.1 A g−1 and 672 mAh g−1 after 500 cycles at 1 A g−1 for lithium ion batteries. The boosted lithium-ion storage performances of the Zn0.76Co0.24S@C@CNF anode are mainly due to the synergistic role of the two different metal sulfides reacting with lithium ions at discrepant voltages, N-/S-doped carbon coating supplying more active sites, and the interconnected 1D conductive nanofibers providing stable electrode structure, efficient transport route for electrons as well as fast lithium diffusion.