Suppressing Hydrogen Evolution and Dendrite Formation on a Zn Anode by Coating InO with Tailored Affinity to H* and Zn.

To suppress the hydrogen evolution reaction (HER) and dendrite formation on the Zn anode in aqueous Zn-ion batteries, a submicrometer InO coating on the Zn anode (referred to as Zn@InO) was constructed via magnetron sputtering. Density functional theory (DFT) and experimental data show that the InO coating suppresses the HER because of its weaker interactions with H* compared with Zn, inhibiting the Volmer step. At the same time, the InO coating exhibits a moderate affinity for Zn*, higher than that on Zn but lower than that at the InO-Zn interface, thus facilitating the desolvation of the hydrated Zn ions while promoting its deposition on the Zn substrate beneath the InO coating. The resultant suppression of side reactions and dendrite growth significantly enhance the reversible plating/stripping of Zn. The optimized Zn@InO stably cycles over 6400 h with a low voltage hysteresis of 9.5 mV at 1 mA cm and 1 mAh cm in symmetric cells. The average Coulombic efficiency of Zn plating/stripping is increased from 95.8 to 99.6% owing to the InO coating. Moreover, when coupled with the MnVO·nHO cathode, the Zn@InO battery maintains a capacity retention of 78.6% after 2000 cycles at 5 A g. This facile and economical modification of Zn anodes provides an idea for realizing the practical application of AZIBs.