Manganese (IV) dioxide (CAS number 1313-13-9) is tetravalent and predominantly used in the battery industry, particularly in alkaline and lithium batteries. It is used extensively in Zn-ion batteries, due to its low cost, high theoretical capacity and sustainability. Zn/MnO2 batteries exhibit high stability, an excellent gravimetric capacity of 450 mAh/g and a 90% capacity retention. They provide an energy density of 150 Wh/kg even under high temperature up of to 55°C.
Manganese dioxide nanoparticles act as reactive oxygen species scavengers by catalyzing the breakdown of hydrogen peroxides, a radical formed from O2-. Manganese dioxide can also be used to dope spiro-OMeTAD, for early and rapid oxidation of spiro-OMeTAD precursor solution, mitigating the adverse effects of air oxidation. This MnO2-doped hole transport layer demonstrates improved morphology, conductivity and better aligned HOMO level with the perovskite active layer. As a result, the external quantum efficiency increases from 83% to 87.6%.