Lithium manganese oxide cathodes have a smaller environmental footprint compared to cathodes with cobalt and nickel. Flame assisted spray pyrolysis (FASP) is an emerging technique that may improve the economics of the process at the commercial scale while controlling purity. LiNO3 reacts with Mn(NO3)2 to form LiMn2O4. Carbon from the flame coats the particles and, together with the Mn oxides, they reduce electrical capacity. The reaction temperature and droplet residence time are the main parameters that determine manganese oxide content and therefore the product purity. LECO carbon analysis confirms that the fuel and precursor type affect carbon content. It increases from 0.1 % with nitrate precursors to 2 % with carbonate and acetate precursors. The temperature profile as well as the solute type and concentration change the product morphology. The particle surface is wrinkled at a mild temperature and blowholes form at a high temperature. Primary nano-crystals (5-8 nm) agglomerate to form 1 mu m polycrystalline particles from a 0.5 mol center dot L-1 nitrate precursors solution, while a 5 mol center dot L-1 solution produces 10 mu m powders. We modelled the reaction kinetics based on thermogravimetric analyses to identify the principle reaction steps. Oxide formation increases below 400 degrees C and above 800 degrees C, while fast heating rates and short residence time reduce purity.