Nickel hydroxides and related materials: a review of their structures, synthesis and properties

This review article summarizes the last few decades of research on nickel hydroxide, an important material in physics and chemistry, that has many applications in engineering including, significantly, batteries. First, the structures of the two known polymorphs, denoted as α -Ni(OH) 2 and β -Ni(OH) 2 , are described. The various types of disorder, which are frequently present in nickel hydroxide materials, are discussed including hydration, stacking fault disorder, mechanical stresses and the incorporation of ionic impurities. Several related materials are discussed, including intercalated α -derivatives and basic nickel salts. Next, a number of methods to prepare, or synthesize, nickel hydroxides are…