Synergy of single atoms and sulfur vacancies for advanced polysulfide–iodide redox flow battery

Aqueous redox flow batteries (RFBs) incorporating polysulfide/iodide chemistries have received considerable attention due to their safety, high scalability, and cost-effectiveness. However, the sluggish redox kinetics restricted their output energy efficiency and power density. Here we designed a defective MoS2 nanosheets supported Co single-atom catalyst that accelerated the transformation of S2−/Sx2− and I−/I3− redox couples, hence endow the derived polysulfide–iodide RFB with an initial energy efficiency (EE) of 87.9% and an overpotential of 113 mV with an average EE 80.4% at 20 mA cm−2 and 50% state-of-charge for 50 cycles, and a maximal power density of 95.7 mW cm−2 for an extended cycling life exceeding…

• NN
  National Natural Science Foundation of China

  Awards: 22469002, 51971157, 22275166, 22109118