A 3D-printed square-hole electrode for dendrite-free zinc–air batteries

Abstract

Rechargeable zinc–air batteries are regarded as the most promising energy storage batteries due to their excellent theoretical energy density, safety and environmental friendliness. However, the uncontrolled growth of zinc dendrites seriously limits the cycling stability and performance of zinc–air batteries. By combining 3D printing with chemical etching and electro-deposition of zinc, 3D Fe//Ni–Zn-1.2 can be prepared which shows excellent reversibility for plating/peeling. The prepared 3D Fe//Ni–Zn-1.2 has a reasonable lattice structure with excellent hydrophilicity, and dendrite-free growth is achieved. As expected, 3D Fe//Ni–Zn-1.2 has a more stable coulombic efficiency and higher stability and cycles continuously for 1050 h at 10 mA cm⁻². With the exactly same electrode geometric area, the tested impedance of the 3D Fe//Ni–Zn-1.2 electrode is 0.074 Ω (0.091 Ω for 2D), indicating that the 3D structure has a more conducive interface with the electrolyte for zinc deposition. Such a reasonable electrode structure provides a solution for the development of high performance energy storage systems.