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

As one of the most promising cathode materials for next-generation batteries, sulfur has been widely used in organic metal-sulfur batteries, especially in Li-S batteries. However, to date, Pb-S chemistry has never been officially reported. In this paper, a reliable aqueous Pb-S battery based on a dual conversion reaction was constructed. To clarify the feasibility, three important thermodynamic parameters of the Pb-S system were analyzed, including the solubility of PbS in aqueous solution, the volume change of the Pb-S battery system, and the potential of the S/PbS cathode redox couple. Here, it is demonstrated that the aqueous Pb-S battery possesses a great advantage in theory, and the inherent insolubility of PbS makes an aqueous Pb-S system without a shuttle effect. Moreover, the conversion-type counter electrode of a Pb-S system with a stable nucleation rate endows it with a dendrite-free nature, which is quite different from the traditional metal-sulfur battery with a stripping/plating–type counter electrode. Benefitting from these remarkable natures, the aqueous Pb-S battery exhibits a high discharge capacity of 1,343.9 mAh g(−1)(sulfur) with a capacity retention of 71.4% after 400 cycles. In addition, the feasibility of this Pb-S system is further demonstrated in a hybrid cell consisting of an S cathode and Zn anode, which affords an energy density of 930.9 Wh kg(−1)(sulfur).