Construction of FeS2@C coated with reduced graphene oxide as high-performance anode for lithium-ion batteries

Abstract

• Ferrocene is introduced to construct rGO@FeS 2 @C composite. • The unique structure of rGO@FeS 2 @C facilitates the diffusion of electrons and ions. • The addition of rGO increases the conductivity and buffer the volume fluctuation. • The rGO@FeS 2 @C composite demonstrates exceptional electrochemical performance. Pyrite (FeS 2 ) is known for one alternative to the promising anode materials for lithium-ion batteries (LIBs) on account of the low price, friendliness to environment and comparable higher theoretical capacity. Nonetheless, its long-term cycling performance is still not satisfied. In our present work, a FeS 2 @carbon composite coated with reduced graphene oxide (rGO) (rGO@FeS 2 @C) was synthesized to settle this problem. With the addition of rGO, the huge volume change was relieved and the big pulverization was also alleviated. When applied as the anode material for LIBs, the rGO@FeS 2 @C electrode could deliver outstanding electrochemical performance owing to its special structure. At 1 A g −1 , it could exhibit a high specific capacity of 820.7 mA h g −1 after 300 cycles. Even if when the current density reaches to a higher degree of 5 A g −1 , rGO@FeS 2 @C could still exhibit a great specific capacity to 600.8 mA h g −1 in the wake of 1100 cycles, which is one of the best results to FeS 2 systems. In addition, we also compare its performance with the commercialized FeS 2 , further confirming the good electrochemical properties of rGO@FeS 2 @C.