Manganese iv dioxide is also known as manganese dioxide is an oxide form of manganese metal with a formula of mno2. Manganese iv oxide is the inorganic compound with the formula mno 2 this blackish or brown solid occurs naturally as the mineral pyrolusite which is the main ore of manganese and a component of manganese nodules the principal use for mno 2 is for dry cell batteries such as the alkaline battery and the zinc carbon battery. Manganese dioxide also known as manganese iv oxide is a chemical compound of manganese and oxygen.