Synergistic dual conversion reactions assisting Pb-S electrochemistry for energy storage.

SignificanceBased on the analysis of three thermodynamic parameters of various M-S systems (solubility of metal sulfides [M x S y ] in aqueous solution, volume change of the metal-sulfur [M-S] battery system, and the potential of S/M x S y cathode redox couple), an aqueous Pb-S battery operated by synergistic dual conversion reactions (cathode: S⇄PbS, anode: Pb 2+ ⇄PbO 2 ) has been officially reported. Benefitting from the inherent insolubility of PbS and a conversion-type counter electrode, the aqueous Pb-S battery exhibited two advantages: it is shuttle effect free and has a dendrite-free nature. Moreover, the practical value of the Pb-S battery was further certified by the prototype S|Pb(NO 3 ) 2 ǁZn(NO 3 ) 2 |Zn hybrid cell, which afforded an energy density of 930.9 Wh kg -1 sulfur .