Abstract
The naturally sluggish redox kinetics and limited utilization associated with the sulfur conversion in Zn/S electrochemistry hinder its real application. Herein, we report an in situ phase reconstruction strategy that activates the catalytic activity of vanadium oxides for invoking redox-catalysis to manipulate reversible sulfur conversion. It was identified that the V(2)O(3)@C/S precursor derived from metal organic frameworks could be transformed into V(2)O(5-m) ·nH(2)O@C/S by a facile electrochemical induction process. Vanadium oxides can realize a faster zinc ion storage process than sulfur components during the discharging process, thereby the pre-zincified Zn (x) V(2)O(5)·nH(2)O behaves as a redox medium to catalyze the sulfur reduction via a spontaneous reaction (Zn (x+1)V(2)O(5) + S = Zn (x) V(2)O(5) + ZnS, △G = -6.4 kJ mol(-1)). For the reverse battery recharging, the electrodeposited ZnS around the active sites can be easily activated and the facile Zn(2+) transport between Zn (x) V(2)O(5)·nH(2)O and ZnS enables the reversible conversion of ZnS back to S (Zn (x) V(2)O(5) + ZnS = Zn (x+1)V(2)O(5) + S, ΔG = -7.02 kJ mol(-1)). Accordingly, the composite cathode delivers a high capacity of 1630.7 mA h g(-1) and maintains stable capacity retention after 150 cycles at 4 A g(-1). The proposed redox catalytic effect sheds light on the tunable Zn-S chemistry.