Electrochemical properties of reheated molten salt synthesized (M1/2Sb1/2Sn)O4 (M = V, Fe, In) cycled in the voltage range of 0.005–1.0 and 0.005–3.0 V

• Mixed metal oxides, (M1/2Sb1/2Sn)O4 (M = V, Fe, In) were synthesized using the molten salt method at 280 °C followed by reheating at 500 °C.
• They were characterized by XRD, SEM and BET surface area techniques.
• Discussed the electrochemical performance in the voltage range, 0.005-3.0 V and 0.005-1.0 V.

Mixed metal oxides (M1/2Sb1/2Sn)O4 (M = V, Fe, In) were prepared using the molten salt method at low temperature followed by reheating the samples at 500 °C in air to improve the crystallinity. The XRD patterns of reheated compounds showed a single phase tetragonal SnO2 type structure. BET surface area test showed that (M1/2Sb1/2Sn)O4 has significantly large specific surface areas of 99, 118 and 46 m2/g for M = V, Fe and In, respectively. Li-cycling mechanism involves alloying–de-alloying reactions of Sn, In and Sb with Li using M = V, Fe as matrix elements. Cyclic voltammetry studies showed similar cathodic peak at ~ 0.11 V from the 3rd cycle onwards and anodic peaks at ~ 0.2 V and ~ 0.6 V from the 1st cycle. Further galvanostatic discharge–charge cycling studies were performed on all compounds at a current density of 60 mA g− 1 and in the voltage ranges of 0.005–1.0 V vs. Li and 0.005–3.0 V vs. Li. All compounds showed stable capacities after 60 cycles with negligible capacity loss when cycled at the low voltage range of 0.005–1.0 V, with decreasing capacity in the order of V, Fe, and In. On the other hand, the results of cycling at the high voltage range of 0.005–3.0 V showed higher reversible capacity at initial cycle and large capacity loss during cycling.

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