Nickel(II) Oxide is a chemical compound with the formula NiO. It appears as a green or black powder and is primarily used in ceramics, glass, and as a catalyst in various chemical reactions. Nickel(II) oxide is an inorganic compound that contains nickel in its +2 oxidation state. This compound is also important in the production of nickel-based batteries, particularly in nickel-cadmium and nickel-metal hydride batteries. Additionally, it can be used in the manufacturing of nickel salts and as a pigment in paints and coatings.