Nanoscale design of zinc anodes for high-energy aqueous rechargeable batteries

Rechargeable zinc-based aqueous batteries have attracted increasing attention because of the merits of inherent safety, high capacity (820 Ah kg−1 and 5854 Ah L−1), and cost effectiveness. However, the poor rechargeability of Zn anodes limits their development in next-generation batteries, which is attributed to the dendrite growth, shape change, passivation, and hydrogen evolution issues in the zinc anodes. Nanomaterial design of Zn anodes provides a pathway to tackle these long-standing challenges to develop electrically rechargeable Zn anodes. In this review, we summarize the most recent advances, including 3D high surface area electrode structure, core/shell structure with surface coatings, and nanocomposites with highly conductive materials, in various strategies for improving zinc electrochemical performance. Additionally, the concepts of molecular design of the aqueous electrolytes with confined water molecules and high salt concentration are introduced. Finally, future opportunities and challenges with zinc-based aqueous batteries are discussed.