"Magnetic Behaviours of a Random Magnet, Ni pMg (1-p)(OH 2)". ^ Enoki, Toshiaki Tsujikawa, Ikuji (1975).CRC Handbook of Chemistry and Physics (99 ed.). ^ CRC Handbook of Chemistry and Physics (84 ed.).Toxicity and related safety concerns have driven research into increasing the energy density of Ni(OH) 2 electrodes, such as the addition of calcium or cobalt hydroxides. The synthesis entails treating aqueous solutions of nickel(II) salts with potassium hydroxide. However, it transforms to β-Ni(OH) 2 in alkaline solutions, leading to many investigations into the possibility of stabilized α-Ni(OH) 2 electrodes for industrial applications. Of the two polymorphs, α-Ni(OH) 2 has a higher theoretical capacity and thus is generally considered to be preferable in electrochemical applications. Reaction 1 Ni(OH) 2 + OH − → NiO(OH) + H 2O + e − Specifically, Ni(OH) 2 readily oxidizes to nickel oxyhydroxide, NiOOH, in combination with a reduction reaction, often of a metal hydride (reaction 1 and 2). Nickel(II) hydroxide is frequently used in electrical car batteries. A nickel-magnesium variant of the mineral, (Ni,Mg)(OH) 2 had been previously discovered at Hagdale on the island of Unst in Scotland. It is found naturally as a translucent emerald-green crystal formed in thin sheets near the boundaries of idocrase or chlorite crystals. The mineral form of Ni(OH) 2, theophrastite, was first identified in the Vermion region of northern Greece, in 1980. In addition to the α and β polymorphs, several γ nickel hydroxides have been described, distinguished by crystal structures with much larger inter-sheet distances. In the presence of water, the α polymorph typically recrystallizes to the β form. The β form adopts a hexagonal close-packed structure of Ni 2+ and OH − ions. The α structure consists of Ni(OH) 2 layers with intercalated anions or water. Nickel(II) hydroxide has two well-characterized polymorphs, α and β. It is electroactive, being converted to the Ni(III) oxy-hydroxide, leading to widespread applications in rechargeable batteries. It is a lime-green solid that dissolves with decomposition in ammonia and amines and is attacked by acids. Nickel(II) hydroxide is the inorganic compound with the formula Ni(OH) 2. The test tube in the middle contains a precipitate of nickel(II) hydroxide
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