Lithium can be used as a coolant due to its high specific heat capacity. Compounds of lithium give fireworks and flares a red color. LiOH (lithium hydroxide) is used to make lithium soaps. These soaps are used to manufacture lubricating greases. Lithium can be used in disposable and rechargeable batteries. Some rechargeable batteries include the lithium-ion battery and the lithium iron phosphate battery. Lithium niobate is used to make cell phone. Lithium is used to absorb neutrons in nuclear fusion. Lithium can be combined with other metals (usually aluminum, cadmium, copper or manganese) to make airplane parts. Lithium hydroxide and lithium peroxide are used to purify air in submarines and on spacecraft. Lithium peroxide is fantastic as it reacts with carbon dioxide to produce oxygen. One of the most important uses of lithium is in the treatment of bipolar disorder and depression. Salts of lithium (such as lithium carbonate and lithium citrate) are mood stabilizers. Lithium can be used in focal lenses for telescopes and common spectacles. Lithium chloride and lithium bromide are effective desiccant. A desiccant is a substances that keeps something (usually a container) dry by absorbing (or adsorbing) water molecules. Lithium, and its hydrides, are used as high energy additives in rocket propellants.