Aqueous zinc batteries are promising for grid-scale energy storage due to their safety and low cost. However, large-format production is hindered by electrolyte consumption, hydrogen gas evolution, and dendrite growth. This study introduces an "open" pouch cell design that releases hydrogen and allows electrolyte replenishment. A gel electrolyte using crosslinked kappa-carrageenan and chitosan prevents leakage and evaporation. A Zn||ZnxV2O5·nH2O multi-layer pouch cell achieved an initial discharge capacity of 0.9 Ah and 84% capacity retention after 200 cycles.
