Nickel carbonate is a chemical compound with the formula NiCO3. It typically appears as a greenish powder and is used in various industrial applications, including the production of nickel salts and as a precursor for nickel oxide. Nickel carbonate is often found in nature as the mineral smithsonite. This compound is soluble in acids but insoluble in water. It can be produced through the reaction of nickel salts with sodium carbonate. Due to its nickel content, it is also of interest in the field of battery technology, particularly for nickel-cadmium and nickel-metal hydride batteries.