Organic additives in alkaline electrolyte to improve cycling life of aqueous Zn–Ni batteries

Aqueous secondary Zn–Ni batteries have attracted extensive attention as a potential candidate to meet the increasing demand for energy storage device since they are environmental friendly and can provide inherent safety, high energy density and power density. However, the uneven deposition, passivation and corrosion of ZnO anode severely reduce the cycling life of the battery. Herein, tetraethylammonium bromide (TEAB) and polyethylene oxide (PEO) are introduced into the battery as electrolyte additives. The Zn–Ni battery achieves an excellent cycling life of 450 h since the additives provide more reduction sites and hinder the formation of dead zinc. In addition, the electrolyte additives can also reduce the corrosion current density of the anode and maintain the stable cycle of the battery under floating charge mode for more than 40 days. These results confirm the great practical application potential of aqueous Zn–Ni battery. • Tetraethylammonium bromide and polyethylene oxide are used as electrolyte additives. • The electrolyte additives effectively increase the reduction sites of zinc. • The batteries exhibit better cyclic stability and floating charge performance.