High-capacity Zn/CFx primary battery enabled by a mixed-cation acetate electrolyte

Aqueous zinc (Zn)/fluorinated carbon (CF x ) primary batteries show great potential for environmentally friendly energy storage technologies owing to their intrinsic safety, low cost, earth-abundant zinc resources and environmental benignity. However, the relatively low equilibrium potential of zinc (Zn/Zn 2+ , −0.76 V vs . SHE) restricts conventional aqueous Zn/CF x systems to low-fluorination CF x cathodes and necessitates highly alkaline electrolytes, which inevitably aggravate the hydrogen evolution reaction (HER). In this work, CF x with a high F/C ratio of 1.05 (CF 1.05 ) is employed as the cathode in a high-performance aqueous Zn primary battery, paired with a rationally designed mixed-cation acetate electrolyte with high ionic conductivity. Unlike conventional aqueous electrolytes, this electrolyte enables accelerated electrochemical kinetics and effective suppression of the HER under weakly alkaline conditions. Consequently, the Zn/CF 1.05 battery achieves a discharge specific capacity of 750 mAh·g −1 at 80 mA g −1 , accompanied by a stable voltage plateau near 0.60 V. Furthermore, a pouch-type Zn/CF 1.05 battery delivers a specific capacity of 574 mAh·g −1 at 160 mA g −1 . These findings establish a viable pathway toward the practical implementation of low-cost, high-capacity aqueous Zn/CF x primary batteries.