A reverse micelles method is used in the synthesis of manganese carbonate. The use of cetyl-trimethylammonium bromide surfactant and hexanol cosurfactant allows the preparation of a new monodispersed form of MnCO3. Particles with a regular shape and ca. 200nm edges are observed by electron microscopy. The electrochemical reaction with lithium of the manganese carbonate leads to the formation of the manganese metal and lithium carbonate as the main side product, which yields higher capacity than graphite and good capacity retention. Submicron MnCO3 could replace other more toxic and expensive anodes used in recent commercial Li-ion products.