Decoding MnO2 redox chemistry from mechanistic ambiguity to design principles for aqueous Zn-ion batteries (opens in new tab)

Manganese dioxide (MnO2) is a leading positive electrode candidate for aqueous zinc-ion batteries, combining safety, high voltage, low cost, and sustainability for grid-scale storage. However, its practical development remains restricted by poor reversibility, rooted in an unresolved mechanistic debate spanning over a decade. Here, we combine operando characterizations, multimodal spectroscopic analyses, and theory to establish a unified picture: proton-primed MnO2 dissolution and subsequent ...