A Multifunctional Mxene Array Interface Coating for High-Rate and Stable Zn Metal Batteries

Abstract

Dendrite growth and volume stress are main internal causes of electrochemical failure of zinc metal battery. To address these questions, this work reports a multifunctional MXene array interface coating strategy to enabling dendrite-free zinc metal anode via laterally ordered deposition. The regulation mechanism of MXene array interface on growth kinetics and deposition behavior of zinc metal are systematically investigated by in-situ optical microscopy and transient simulation at the mesoscopic scale, in-situ Raman spectroscopy and in-situ X-ray diffraction technique at the microscopic scale, as well as density functional theory calculation at the atomic scale, respectively. As a result, benefited from the multi-scale synergistic effect of the vertically aligned MXene array interface, the assembled symmetric cell can steadily work at 0.5 mA cm-2 for over 1300 h and even the ultrahigh current density of 20 mA cm-2 and fixed areal capacity of 10 mA cm-2, demonstrating it the ultrahigh-rate and large-capacity performance. Moreover, rate capability and cyclic stability of Zn//VO2 full cell also can be significantly improved when adopted such MXene array@Zn anode. This work provides a new insight on dendrite-free deposition mechanism to develop stable metal anodes including but not limited to zinc metal.

Keywords: Dendrite growth, MXene array interface, synergistic effect, laterally ordered deposition, Zinc metal anode