In Situ Derivatization for Boosted Lithium Storage Performance of Fe7S8/C Hollow Nanospheres

Abstract

AbstractIn this paper, Fe3O4 nanoparticles (Fe3O4 NPs) with an average diameter of 10 nm were grown in situ on the shell of hollow mesoporous carbon nanospheres (HMCNs) to form a new type of sesame balls‐like Fe3O4/C hollow nanospheres (HNSs) by thermal decomposition. After vulcanization and phosphating, Fe3O4/C HNSs are transformed into Fe7S8/C HNSs and Fe(PO3)2/Fe2O3/C HNSs, respectively. Compared with Fe3O4/C HNSs and Fe(PO3)2/Fe2O3/C HNSs, Fe7S8/C HNSs display good cycling stability as anode material for lithium ion batteries. When the current density is 1 A g−1, the reversible specific capacity of Fe7S8/C HNSs is 1006 mA h g−1 after 250 cycles. The rate performance and electrochemical properties of Fe7S8/C HNSs are significantly improved. Research shows that the capacitive behavior plays a major role in specific capacity contribution of Fe7S8/C HNSs electrode. The anchoring of Fe7S8 NPs on the shell of HMCNs avoids the aggregation of Fe7S8 NPs, promote the conductivity of composite and boost the delivery of electrons. This idea and expedient method of construction can be broadened to synthesize other hollow nanostructured material with preferable electrochemistry performance.