Zn–Ni reaction in the alkaline zinc-air battery using a nickel-supported air electrode

Zinc-air batteries would be a promising candidate for energy conversion and storage because of their dense energy and effective cost. The metal nickel is extensively used for current collection and framework support of the air electrode in consideration of its outstanding anticorrosion property and conductivity. However, the reaction of zinc and nickel in zinc-air batteries has not been reported. Here, we show a novel zinc-air battery with a reverse structure of the air electrode based on Zn–Ni reaction, where nickel foam of the air electrode is oriented toward the zinc electrode, protecting the catalytic layer of the air electrode from impurity coverage and inhibiting dendrite growth. A zinc-air primary battery with the reverse air electrode exhibits a stable discharging ability of >1000 h around 1.4 V, achieving a capacity of 0.73 A h g_Zn⁻¹ and a specific energy of 874 W h kg_Zn⁻¹. Moreover, a zinc-air secondary battery with the reverse air electrode obtains more than 700 h cycles at the current density of 10 mA/cm² without battery failure.