Preparation of porous FeS2-C/RG composite for sodium ion batteries

Pyrite (FeS 2 ) is considered to be one of the most promising anode materials for sodium ion batteries (SIBs) due to its high theoretical capacity, natural abundance, low cost and low toxicity, but the commercial process of FeS 2 is always limited by its low conductivity and volume expansion during the charge-discharge process. Herein, a three-dimensional porous composite (FeS 2 -C/RG) is constructed using FeS 2 -C nanoparticles and reduced graphene oxide through one-step vulcanization of PB (Prussian blue)/GO (graphene oxide) gel. As the anode material of SIBs, FeS 2 -C/RG exhibits high electrochemical performance benefiting from the unique three dimensional structure and small FeS 2 -C nanoparticles. The initial specific capacity can reach 1196 mAh g −1 at 0.1 A g −1 and it can still remain 543.0 mAh g −1 after 100 cycles at 0.5 A g −1 . Even at 6 A g −1 , the capacity could maintain 291.7 mAh g −1 after 1000 cycles. The excellent rate and cycling performance of FeS 2 -C/RG indicate it is a promising anode material for rechargeable SIBs.