Roughened Graphite Collector Coupled with Hydrolysis‐Resistance Zinc Chloride Electrolyte Enables Large‐Size Rechargeable Ag–Zn Battery.

Ag–Zn batteries have the advantages of being a high‐safety and stable discharge platform but still face challenges such as high cost, electrolyte hydrolysis, and zinc dendrites. In this study, a low‐cost roughness graphite paper (GP) enables more uniform loaded Ag particles to construct Ag/rough graphite paper (Ag/RGP) cathode with high wettability of low‐concentration ZnCl2 electrolyte, achieving both capacity and reversibility enhancement. Both a few additions of citric acid (CA) to the low‐concentration ZnCl2 electrolyte can also inhibit the hydrolysis of Zn2+ and increase the nucleation overpotential due to suitable acidity and complexation ability, resulting in more even Zn deposited behavior on low‐cost Zn foil anode. Meanwhile, the ZnCl2‐CA electrolyte can also promote redox reaction and thus improve the capacity of the Ag/RGP cathode. As a result, the assembled large‐size Ag–Zn battery (50 cm2) with low‐cost Ag/RGP and low‐concentration ZnCl2‐CA obtains a capacity of 0.76 mAh cm−2 at a current density of 0.4 mA cm−2, with a cycle life of ≈100% capacity retention over 50 cycles, also easily powering a LED array and displaying high practicability. This work provides a feasible and practical route to fabricate large‐size and low‐cost Ag–Zn batteries. [ABSTRACT FROM AUTHOR]