Domino-like Ion Transport: Advanced Mn 2+ -Alginate Coatings For The Positive Electrode In Zinc-Manganese Dioxide Batteries

Abstract The future of stationary energy storage demands not only sustainable but also high-performance technologies — and aqueous zinc–manganese dioxide batteries offer considerable potential. This study presents an innovative next step for this technology: A $\mathrm{Mn^{2+}}$-conductive alginic acid coating that actively guides ion transport and significantly enhances the efficiency of the electrochemical cycle. Through a comprehensive analysis combining electrochemical experiments with scanning electron microscopy and impedance spectroscopy, we demonstrated that the Mn-alginate layer not only enables homogeneous $\mathrm{MnO_2}$ deposition but also prevents the loss of active material — even after extended cycling. The proposed "domino-like" ion transport model illustrates how the coating surpasses simple diffusion by enabling directed migration of $\mathrm{Mn^{2+}}$ ions via controlled Coulombic repulsion. The result: significantly improved Coulombic and energy efficiencies, along with a stable internal resistance. This work not only provides mechanistic insight but also introduces a scalable strategy for the optimization of ZMB-systems battery systems - making a next step toward the next generation of sustainable energy storage technologies.