Used in electroplating processes to provide a protective and decorative nickel coating on metals, enhancing corrosion resistance and surface hardness. Commonly employed in the production of batteries, especially nickel-cadmium and nickel-metal hydride types, due to its role in forming active electrode materials. Serves as a catalyst precursor in industrial chemical reactions and as a mordant in textile dyeing to improve color fastness. Also utilized in the preparation of other nickel compounds and in microbiological culture media as a source of nickel ions.