Quantitative Design Targets and Practical Pathways for High-Energy-Density Aqueous Zinc–Metal Batteries

Aqueous zinc metal batteries (AZMBs) have attracted considerable attention for their stationary electrochemical energy storage (SEES), owing to their inherent high safety and environmental friendliness. However, the majority of current research remains confined to idealized testing conditions─characterized by low areal capacity, limited zinc utilization, excessive electrolyte volume, and heavy inactive components─while focusing predominantly on isolated performance metrics. Although such conditions often yield impressive lab-scale performance, they fail to translate into practically viable AZMBs that compete with other state-of-the-art battery technologies in terms of energy density, cycle life, and levelized cost of storage (LCOS). To bridge the gap between lab-scale devices and real-world deployment, this review proposes quantitative targets and provides a design model tailored to practical AZMBs. We systematically analyze the scientific and engineering challenges of this practical battery model and summarize viable strategies across materials and battery design. Finally, we discuss critical but often overlooked issues and provide forward-looking perspectives on future research directions. This review aims to build a strategic roadmap to overcome the bottlenecks in current AZMB research and accelerate the development of long-life, high-energy-density, and low-cost AZMBs for SEES.