Core-Shell Fes2@Nsc Grown on Graphene for High Performance Lithium-Ion Storage

Abstract

FeS2 is considered a promising anode candidate for LIBs due to its low cost and high theoretical capacity. However, the large volume expansion and low conductivity of FeS2 limit its further applications. In this work, a novel FeS2-based materials with two-carbon structure has been designed to solve the above problems. This unique structure is constructed of spindle-shaped FeS2 nanoparticles embedded in N/S co-doped carbon shell and covered by three-dimensional sulfur-doped graphene (FeS2@NSC/SG). The FeS2@NSC/SG composite shows excellent lithium storage performance benefiting from the unique two-carbon structure. FeS2@NSC/SG electrode delivers a reversible capacity of 944.6 mAh·g-1 after 120 cycles at 0.1 A·g-1 when it is used as anode for LIBs. Even at 5 A·g-1, the capacity of FeS2@NSC/SG electrode remains 270.8 mAh·g-1 after 500 cycles. The excellent rate performance of FeS2@NSC/SG electrode is attributed to the electrochemical behavior dominated by the capacitive behavior and this strategy will provide new ideas for potential electrode materials.

Keywords: LIBs, Anode, FeS2, Graphene, N/S doping