Nutrient for Inhibiting the Activity of H2O and Optimizing Interfacial Chemistry for Aqueous Rechargeable Zn-Ion Batteries

Reducing the free radicals associated with electrochemical reactions and the activity of H2O is an effective measure to inhibit side reactions and improve stability for rechargeable aqueous Zn-ion batteries. Herein, methylsulfonylmethane (MSM), a popular dietary supplement for humans, is used as an innoxious and low-cost additive to scavenge free radicals and optimize the coordination condition for aqueous ZnSO4 electrolyte. Profiting from the double effects of MSM, the Zn∥Ti asymmetric cells exhibit excellent stability and display a high Coulombic efficiency (CE) of 99.5% in the aqueous MSM/ZnSO4 electrolyte for 1000 h, and the Zn∥Zn cells achieve a long cycle life of over 2000 h. In addition, MSM can effectively suppress the dissolution of an ammonium vanadate (NVO) cathode. The positive role of MSM is further exhibited in the Zn∥NVO and Zn∥PANI full cells, exhibiting outstanding charge/discharge performance and capacity retention. This work provides a type of innoxious additive for an aqueous electrolyte for aqueous rechargeable zinc-ion batteries.