Confining FeS in graphitized carbon with void space for high and stable electrochemical storage performance of Na ⁺ and K ⁺

Abstract

Summary Ferrous sulfides have high theoretical capacity in the electrochemical storage of Na‐ion and K‐ion, but its obvious volume change during the storage process greatly affects its cycling performance at high current density. In this regard, we construct a unique composites structure of Nitrogen‐doped carbon shell coated FeS nanoparticle with inner void spaces. As an anode in Na‐ion and K‐ion batteries, this structure could provide excellent cycling performance at high rate of charge/discharge process (560 mAh/g at 0.5 A/g for 300 cycles in Na‐ion battery and 322 mAh/g at 1 A/g for 300 cycles in K‐ion battery). Further research finds the inner void space could not only provide buffer space for the volume change of FeS nanoparticles, but also maintain a stable outer carbon shell during the electrochemical process. These behaviors greatly promote the reversibility of FeS at high rate charge transfer process. Consequently, the construction of inner void space in graphitized carbon shell in this work could be considered as an important reference for the promotion of electrochemical storage in other transitional metal compound system.

Mechanochemical synthesis of SnS anodes for sodium ion batteries

“…23,24 The peak located at 162.8 eV could be assigned to the binding energies of the S 2− of SnS ( Figure 2C). 25,26 Further FTIR analysis were pursued in order to demonstrate that the tin and sulfur are transformed into SnS phase. Figure 2D shows the FTIR spectra of tin powder, sulfur powder, SnS 2 hours and SnS 20 hours samples that are different from each other resulting their characteristic peaks.…”

Enhanced sodium storage performance of silk fibroin‐derived hollow iron sulfide with potential window control

“…The pseudo‐capacitance contribution ratio of Fe 7 S 8 electrodes is strongly dependent on the kinetics rate, which significantly affects the rate performance of the electrodes 34 . The nano‐structuring, carbon composite, and potential window control are known to be effective to improve the sluggish kinetic of iron sulfide materials 19,30,33,35‐37 . In the case of a material that does not contain carbon, controlling the potential window is an efficient approach to improve the pseudo‐capacitance of many iron sulfide electrodes.…”

“…34 The nano-structuring, carbon composite, and potential window control are known to be effective to improve the sluggish kinetic of iron sulfide materials. 19,30,33,[35][36][37] In the case of a material that does not contain carbon, controlling the potential window is an efficient approach to improve the pseudo-capacitance of many iron sulfide electrodes. This indicates that the optimization of the reaction mechanism by controlling the potential window improved the rate performance of the Fe 7 S 8 HM electrodes over the potential window of 0.4 to 3 V.…”