fig4

Figure 4. Reaction kinetics investigation of FeNiS₂ QDs@SPAN and SPAN electrodes. (A) The comparison of peak voltages for FeNiS₂ QDs@SPAN and SPAN electrodes from the CV curve; (B and C) Tafel plots of the cathodic reduction process, and the anodic oxidation process; Impedance spectroscopy of the (D and E) EIS spectra of FeNiS₂ QDs@SPAN and SPAN before and after 200 cycles at 2 C; (F) Internal resistances of the FeNiS₂ QDs@SPAN and SPAN electrode relative to the normalized discharge-charge time; (G) Li⁺ diffusion coefficients calculated from GITT profiles according to overpotential; Adsorption configurations of (H) Li₂S and (I) Li₂S₂ on the FeNiS₂ (102) surface. QDs: Quantum dots; SPAN: sulfurized polyacrylonitrile; EIS: electrochemical impedance spectroscopy; GITT: galvanostatic intermittent titration technique.