Figure 3: Sodium-storage mechanism of Na/FeS battery.
From: Uniform yolk-shell iron sulfide–carbon nanospheres for superior sodium–iron sulfide batteries
(a) Charge/discharge profiles of the micro-FeS electrode for the first cycle at 50 mA g−1; (b) the corresponding ex-situ XRD patterns with the standard XRD patterns of Na2S and Na2CO3 (inset), and (c) the respective ex-situ Fe 2p XPS spectra of the micro-FeS electrode at the denoted states.
