Fe₇Se₈ encapsulated in N-doped carbon nanofibers as a stable anode material for sodium ion batteries.

ABSTRACT: Transition metal chalcogenides especially Fe-based selenides for sodium storage have the advantages of high electric conductivity, low cost, abundant active sites, and high theoretical capacity. Herein, we proposed a facile synthesis of Fe₇Se₈ embedded in carbon nanofibers (denoted as Fe₇Se₈-NCFs). The Fe₇Se₈-NCFs with a 1D electron transfer network can facilitate Na⁺ transportation to ensure fast reaction kinetics. Moreover, Fe₇Se₈ encapsulated in carbon nanofibers, Fe₇Se₈-NCFs, can effectively adapt the volume variation to keep structural integrity during a continuous Na⁺ insertion and extraction process. As a result, Fe₇Se₈-NCFs present improved rate performance and remarkable cycling stability for sodium storage. The Fe₇Se₈-NCFs exhibit practical feasibility with a reasonable specific capacity of 109 mA h g^-1 after 200 cycles and a favorable rate capability of 136 mA h g^-1 at a high rate of 2 A g^-1 when coupled with Na₃V₂(PO₄)₃ to assemble full sodium ion batteries.

SUBMITTER: Hu L 

PROVIDER: S-EPMC9419117 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature