Cobalt(II) oxalate is the inorganic compound with the formula of CoC2O4. Like other simple inorganic oxalates, it is a coordination polymer. The oxalate ligands bridge of Co(OH2)2 centres. Each cobalt adopts octahedral coordination geometry.[1]
It is used in the preparation of cobalt catalysts, and cobalt metal powder for powder-metallurgical applications. It is made in process of recycling lithium-ion batteries, where the cobalt is obtained from cathode material (LiCoO2) by leaching with sulfuric acid and then precipitated with ammonium oxalate.
Many cobalt(III) oxalate complexes are known, including [Co(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>]3- and [Co(C<sub>2</sub>H<sub>4</sub>(NH<sub>2</sub>)<sub>2</sub>)C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>]−.[2] [3]