Self-assembled FeS2 cubes anchored on reduced graphene oxide as an anode material for lithium ion batteries

Abstract

A novel composite of reduced graphene oxide (RGO) and FeS₂ microparticles self-assembled from small size cubes as a high-performance anode material for lithium-ion batteries (LIBs) has been prepared via a facile one-pot hydrothermal method. The prepared composite shows interconnected networks of reduced graphene oxide sheets and well-dispersed FeS₂ microparticles which were composed of small-size cubic FeS₂ crystals. The composite not only provides a high contact area between the electrolyte and the electrode, favorable diffusion kinetics for both electrons and lithium ions, but also provides the protection against the volume changes of electroactive FeS₂ materials and excellent electrical conductivity of the overall electrode during electrochemical processes as well as an enhanced synergistic effect between cubic FeS₂ and RGO. As an anode material for LIBs, it exhibits a very large initial reversible capacity of 1147 mA h g⁻¹ at a current rate of 100 mA h g⁻¹ and maintains 1001.41 mA h g⁻¹ over 60 cycles, which is much higher than that of the theoretical capacity of graphite (372 mA h g⁻¹) and indicates high stability. The results demonstrate that the composite can be a promising candidate for electroactive materials in LIBs.