Dendrite-free Zn anodes enabled by interface engineering for non-alkaline Zn-air and Zn-ion batteries

Aqueous zinc-metal batteries hold immense promise for large-scale energy storage applications due to their cost-effectiveness and superior safety features. However, uncontrolled dendrite growth, corrosion and side reactions in aqueous environments destabilize the electrode/electrolyte, leading to Zn plating/striping irreversibility. Herein, a low-cost, non-toxic functional electrolyte additive, tetraethyl ammonium bromide (TEAB), addresses this challenge. The preferential adsorption of TEAB on the surface of the Zn anode endows the Zn/electrolyte interface with an optimized electric field distribution and abundant active sites for the uniform and dendrite-free Zn2+ deposition. Moreover, TEAB disrupts the H-bond network between the electrolytes, effectively suppressing water-induced side reactions and corrosion. Consequently, a Zn||Zn symmetric battery achieves a long cycle life of 4,950 h at 1 mA cm-2, and the average coulombic efficiency of the Zn||Cu battery reaches as high as 99.5%. Additionally, even after 2,000 cycles at 3 A g-1, the capacity retention of the Zn||MnO2 battery remains at 91.22%. The non-alkaline full Zn||air batteries deliver remarkable cycling stability up to 270 h.