Used as a precursor in the production of cobalt oxide pigments for ceramics and glass, giving deep blue colors. Employed in the synthesis of battery materials, especially in cathodes for lithium-ion batteries. Acts as a catalyst in certain oxidation reactions and in the electrochemical oxidation of water. Utilized in the preparation of other cobalt salts and in some moisture-sensitive applications due to its reactivity with acids. Also found in some specialty coatings and in the development of supercapacitors and electrochromic devices.