Circumventing the zinc dendrites via contact-actuated aspectant growth

Aqueous zinc batteries (AZBs) are long deemed as one of the most promising high-safe energy storage devices. However, the Zn anode still suffers severe dendrite growth, which greatly hinders the practical deployment of AZBs. Here, a functionalized separator with pre-embedded nucleation seeds was designed to intentionally tune the Zn deposition direction. Upon plating, the pre-stored Zn@In particles could induce the Zn deposition from separator toward anode, and hence, an aspectant Zn growth simultaneously from the anode and the functional layer of separator is conduced. Once the growth frontiers of the deposited Zn from the two aspects contact with each other, the contact-actuated equipotential within these areas would eliminate the vertically-distributed electric field and drive the dendrite growth along transverse direction, finally leading to a dense Zn deposition. Such a regulation of deposition direction thereby rendered a vastly enhanced cycling life of Zn//Zn symmetric cell from 72 h to 2100 h (1 mA cm−2 and 1 mAh cm−2). This strategy was also proved viable in other types of separators and cell configurations, providing a new methodology to improve the performance of AZBs via smartly regulating the Zn deposition direction.