Design of pyrite/carbon nanospheres as high-capacity cathode for lithium-ion batteries

Transition metal sulfides are emerging as promising electrode materials for energy storage and conversion. In this work, hierarchical FeS2/C nanospheres are synthesized through a controllable solvothermal method followed by the annealing process. Spherical FeS2 core is homogeneously coated by thin carbon shell. The hierarchical nanostructure and carbon coating can enhance electron transfer and accommodate the stress originated from the volume change as well as suppress the shuttle effect of polysulfide. Consequently, as the cathode material of lithium ion batteries (LIBs), the FeS2/C nanospheres exhibit high reversible capacity of 676 mAh g(-1) and excellent cycling life with the capacity retention of 97.1% after 100 cycles. In addition, even at the high current density of 1.8 C, a reversible capacity of 437 mAh g(-1) is obtained for the FeS2/C nanospheres, demonstrating its great prospect for practical applications in high-performance LIBs. (C) 2019 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.