A low external temperature method for synthesis of active electrode materials for Li batteries – Part A: Synthesis of pure manganese spinel

A low external temperature method (LETM) of active electrode material synthesis for lithium ion batteries has been proposed. The method consists of a two-step process, which is comprised of drying fine droplets of a solution of the starting compound in a liquid drying agent at 200°C, followed by calcination of the obtained precursor in a fluidised bed at a furnace temperature of 300°C. The method prevents uncontrolled growth of particles during the initial thermal pre-treatment and the final firing process. Lithium manganese spinel has been selected for describing the proposed LETM of synthesis. The properties of the spinel obtained by LETM are compared with those of a spinel obtained by the classical immobilised solid state synthesis at 750 °C. On electrochemical cycling, the capacity loss after 100 cycles of the LETM spinel at 11% is significantly lower than that for the spinel prepared by solid state methods (21.5%). However, only 3% difference is seen in the total integral capacity over the 100 cycles between spinels prepared by the different methods.