In-situ formation of Co1−xS hollow polyhedrons anchored on multichannel carbon nanofibers as self-supporting anode for lithium/sodium-ion batteries

Abstract

The as-prepared binder-free Co 1−x S/MCF anode exhibits the desirable electrochemical performance for LIBs and SIBs, which can be attributed to the unique hierarchical nanostructure which provides enough active sites and internal space for volume expansion. • The flexible Co 1−x S/MCF electrode is prepared via the electrospinning technique. • The Co 1−x S/MCF presents hierarchically hollow and multichannel structures. • The Co 1−x S/MCF electrode can effectively ease the huge volume expansion. • The Co 1−x S/MCF electrode shows high electrochemical performance for LIBs and SIBs. The exploration of prospective electrode materials represents great challenges for remarkable lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Herein, we report a reliable synthetic approach for the in-situ growth of the Co-based zeolitic imidazolate framework (ZIF-67) on electrospun nanofibers, followed by carbonization and sulfurization with the formation of free-standing Co 1−x S hollow polyhedrons anchored on multichannel carbon nanofibers (Co 1−x S/MCF) for LIBs and SIBs. The Co 1−x S/MCF electrode displays a high reversible capacity (813 mAh g −1 over 180 cycles at 0.1 A g −1 ), and stable cycle performance (559 mAh g −1 for 300 cycles at 1 A g −1 ) in LIBs. For SIBs, Co 1−x S/MCF electrode exhibits a favorable Na-storage capacity (433 mAh g −1 over 120 cycles at 0.1 A g −1 ). The as-prepared binder-free Co 1−x S/MCF anode demonstrates the advanced electrochemical properties for LIBs and SIBs. It is attributed to the particular multichannel nanostructure and the Co 1−x S hollow polyhedrons (Co 1−x S HPs), which provide enough active sites, and the internal void space effectively reduces the structural strain and eases the volume expansion to maintain structural integrity. This work gives insights to design a unique structure for promising LIBs and SIBs.