Nickelhydroxid

Nickelhydroxid is an inorganic compound with the chemical formula Ni(OH)2. It is also known as nickel(II) hydroxide or nickelous hydroxide. In its pure form, it appears as a pale green solid. It is practically insoluble in water but dissolves in acidic solutions. Nickelhydroxid is a key component in the cathode of nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) rechargeable batteries. During the discharge of these batteries, nickelhydroxid is oxidized to nickel oxyhydroxide, NiO(OH). Conversely, during charging, nickel oxyhydroxide is reduced back to nickelhydroxid. This reversible electrochemical reaction is fundamental to the operation of these battery types. Nickelhydroxid can be synthesized through various methods, including the precipitation of nickel(II) salts with a base such as sodium hydroxide. It also occurs naturally in trace amounts in some mineral deposits. Beyond its use in batteries, nickelhydroxid finds applications as a catalyst and in the production of other nickel compounds.