Ferric phosphate

Iron phosphate is an inorganic compound with the chemical formula FePO4. Several related substances are known, including the tetramorph FePO4 and the dimorph FePO4·(H2O)2 dihydrate.
Iron phosphate is one of the few molluscicides approved for use in organic agriculture.[5] Unlike the previously used metaldehyde, it is non-toxic to pets and wildlife. It is used in steel and metal manufacturing processes. Iron phosphate bonds to metal surfaces, preventing further oxidation. Its presence may partly explain the corrosion resistance of the Delhi Iron Pillar. Iron phosphate coatings are also primarily used as a base coat to increase adhesion to iron or steel surfaces and are often used for rust prevention. It can also be used to bond fabric, wood, or other materials to the surfaces of these materials. Iron phosphate is typically applied as part of a painting or powder coating process. Despite its low electrical conductivity, iron phosphate can also be used as an embedded electrode in lithium-ion batteries. However, its use as an electrode material has become more common in recent years as materials engineers have overcome the conductivity problem. Because FePO4 is thermally stable and generally easy to recycle, it is an ideal electrode material for electric vehicle batteries.