Alkaline Tolerant Antifreezing Additive Enabling Aqueous Zn||Ni Battery Operating at −60 °C

Abstract

Alkaline aqueous batteries such as the Zn||Ni batteries have attracted substantial interests due to their merits of high energy density, high safety and low cost. However, the freeze of aqueous electrolyte and the poor cycling stability in alkaline condition have hindered their operation in subzero conditions. Herein, we construct a stable aqueous electrolyte with lowest freezing point down to −90 °C by adding dimethyl sulfoxide (DMSO) as alkaline tolerant antifreezing additive into 1 M KOH solution. Meanwhile, we find the DMSO can also retard Zn anode corrosion and prevent Zn dendrite formation in alkaline condition, which enables the Zn plating/stripping over 700 h cycle at 1 mA cm⁻² and 0.5 mAh cm⁻². The fabricated Zn||Ni battery can endure low working temperature even down to −60 °C and its dischage capacity retains 84.1 % at −40 °C, 60.6 % at −60 °C at 0.5 C. Meanwhile, it can maintain 600 cycles with a specific capacity retention of 86.5 % at −40 °C at 2 C.