In-situ induced sulfur vacancy from phosphorus doping in FeS2 microflowers for high-efficiency lithium storage

In this work, via in-situ induction of phosphorus doping, FeS2 microflowers with sulfur vacancies were rationally designed and fabricated for lithium-ion batteries (LIBs). Phosphorus doping enlarged interlayer spacings, effectively enhanced the conductivity and facilitated the diffusion and intercalation/dein-tercalation of Li thorn . Moreover, the in-situ induced sulfur vacancies also partly rearranged electronic structures and increased more active adsorption sites for Li thorn . The P1.0-FeS2-x electrode delivered the excellent rate performance (642.6 mAh/g at 5.0 A/g) and long-cyclic performance (544.7 mAh g-1 at 2.0 A/g after 1000 cycles). X-ray absorption fine structure spectroscopy was employed to reveal the decrease of Fe oxidation state and coordination number, confirming sulfur vacancies were in-situ induced through phosphorus doping process. Density function theory calculation declared the doping of phos-phorus atoms and in-situ induced sulfur vacancies in FeS2 could effectively adjust the charge distribution at the active sites for Li adsorption, which enhanced the conductivities and facilitated the electro-chemical reaction kinetics. The anionic doping strategy may provide new ideas and routes of con-structing transition metal sulfides for high-performance LIBs.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this work, FeS2 microflowers with sulfur vacancies were designed and fabricated for lithium-ion batteries via in-situ induction of phosphorus doping. The phosphorus doping enlarged interlayer spacings, enhanced the conductivity, and facilitated the diffusion and intercalation/deintercalation of Li ions. The in-situ induced sulfur vacancies rearranged electronic structures and increased active adsorption sites for Li ions. The P1.0-FeS2-x electrode achieved excellent rate performance and long-cyclic performance.