Targeted adsorption of MXene quantum dots enables preferential growth of Zn (002) plane for stable and reversible zinc anode

Detrimental side reactions and irregular zinc dendrite growth restrict the development of aqueous zinc ion batteries (AZIBs). Although the deposition dominated by Zn (002) crystal plane is proved to mitigate the issues of side reaction and zinc dendrites, inducing the oriented deposition of Zn (002) plane faces thermodynamic challenges. Herein, we use MXene quantum dots (F-MQDs) as an electrolyte additive, which orientedly adsorb on the Zn (002) crystal plane, as a target to guide the preferential deposition of zinc ions. Benefit from the abundant fluorine (F) on the surface, F-MQDs shows a higher absorption energy on the Zn (002) plane than other planes. The installed F-MQDs further preferentially adsorb Zn ions and thus guides the Zn (002)-oriented deposition. As the exposed Zn (002) is the plane that has the lowest surface energy, the suppression of HER, prohibition of zinc corrosion and the elimination of zinc dendrite are achieved synchronously. As a result, the symmetrical Zn||Zn cell shows a prolonged lifespan up to 650 h at the current density and deposition capacity of 1 mA cm −2 and 1 mA h cm −2 . Asymmetric Zn||Cu cell also yield a high average coulombic efficiency of 99.67%. Zn||V 2 O 5 full cells also demonstrate a augmented cycling performance with the highest specific capacity of 133.1 mAh g −1 at 5 A g −1 . This work provides an insight in targeted deposition for achieving high-performance AZIBs.