Engineering continuous coordination architectures for relay Zn2+ transport in gel electrolytes toward high-rate and long-life aqueous zinc-ion batteries.

Aqueous zinc-ion batteries are challenged by sluggish Zn2+ transport, interfacial polarization, dendrite growth, and parasitic reactions. Although functionalized gel electrolytes have been widely developed to regulate Zn deposition, the spatial organization of coordination sites and its influence on Zn2+ transport remain unexplored. Herein, we introduce the spatial organization of coordination sites as a design strategy for engineering gel electrolytes with relay Zn2+ transport. By integrating iminodiacetic acid-functionalized sodium alginate with polyacrylamide, carboxylate- and amide-containing coordination sites are spatially organized into a dynamically accessible multisite coordination environment, herein termed a continuous coordination architecture, which facilitates inter-site coordination exchange of Zn2+. This coordination architecture reconstructs the solvation environment and hydrogen-bonding network, enabling relay-mediated Zn2+ migration, homogenized ion flux, and planar Zn deposition. Consequently, the gel electrolyte exhibits a high ionic conductivity of 11.21 mS cm-1 and a Zn2+ transference number of 0.81. Zn||Zn symmetric cells achieve stable cycling for over 8200 h, while full cells employing NaV3O8·1.5H2O (NVO) cathodes sustain 46,000 cycles at 30 A g-1 and retain a reversible capacity of 100 mAh g-1 at 45 A g-1. This work establishes the spatial organization of coordination sites as a molecular design principle for engineering continuous coordination architectures for relay Zn2+ transport in high-rate, long-lifespan aqueous zinc-ion batteries.