A 3D alloy with (101) oriented planes toward deeply dischargeable zinc metal anode

Abstract

Aqueous zinc metal batteries are promising energy storage systems owing to their intrinsic safety, cost-effectiveness, and environmental friendliness. However, achieving high practical Zn utilization remains challenging. Herein, we report a series of Zn alloys supported on nickel foam (denoted as Ni@Zn-M, M=Sn, Pb, and Bi) that exhibit improved Zn plating/stripping performance at high depth of discharge (DOD). It is revealed that Bi can induce Zn to grow along the Zn (101) crystal plane and reduce the amount of grain boundary. Due to the significantly preferred Zn (101) crystal plane, the porous scaffold, and strong hydrogen evolution inhibition as well as anti-corrosion capability, the Ni@Zn-Bi anode exhibits the best performance. It maintains stability for over 5,000 h, far exceeding the lifespan of counterparts (<1400 h). Moreover, it realizes a lifespan of 1100 h with a high coulombic efficiency (CE) of 99.76% at 40% DOD, and preserves a lifespan of about 400 h with a CE of 94.1% even at 80% DOD. Besides, a Zn-I 2 full battery built on the Ni@Zn-Bi anode sustains more than 5500 cycles at 1 A g -1 . This work provides an alloying strategy and insights to enhance the deep cycling of Zn metal anodes.