Ion Tunnel Matrix Initiated Oriented Attachment for Highly Utilized Zn Anodes.

Metallic zinc is an ideal anode for aqueous energy storage, however, Zn anodes suffer from nonhomogeneous deposition, low reversibility and dendrite formation; these lead to an over-provision of zinc metal in full cells. Herein, we report oriented-attachment-regulated Zn stacking initiated through a trapping-then-planting process with a high zinc utilization rate (ZUR). Due to the isometric topology features of cubic-type Prussian blue analogue (PBA), the initial Zn plating occurs at specific sites with equal spacing of ∼5 Å in the direction perpendicular to the substrate; the trace amount of zinc ions trapped in tunnel matrix provides nuclei for the oriented attachment of Zn (002) deposits. As results, the PBA-decorated substrate delivers high reversibility of dendrite-free zinc plating/stripping for more than 6600 cycles (1320 h) and achieves an average Coulombic efficiency (CE) of 99.5% at 5 mA cm -2 with 100% ZUR. Moreover, the anode-limited full cell with a low negative-positive electrode ratio (N/P) of 1.2 can be operated stably for 360 cycles, displaying an energy density of 214 Wh kg -1 ; this greatly exceeds commercial aqueous batteries. This work provides a proof-of-concept design of metal anodes with high utilization ratio and a practical method for developing high energy density batteries. This article is protected by copyright. All rights reserved.