Metal-Air Flow Batteries Using Water Based Electrolytes
FSU researchers introduce new lithium (Li)-air flow batteries aimed to overcome major disadvantages of traditional Li-air batteries such as low current density and poor cyclability. The battery consists of three Units: the electrochemical (EC) reaction unit, the electrolyte storage unit, and the oxygen exchange unit which mimics the structure of a classical fuel cell system.
Traditional Li-air batteries have an extremely large theoretical energy density, but suffer from several drawbacks:
- The Li20 2/Li20 discharge product deposits on the air side of the electrode reducing the pore size and limiting the access of the 0 2 in the cathode
- The cyclability and energy efficiency of Li-air batteries are poor due to the lack of effective catalysts to convert solid Li20 2/Li20 discharge products into Li ions
- The current and power densities of Li-air batteries are much lower compared to conventional batteries due to extremely low oxygen diffusion coefficient in liquid solution
The FSU batteries overcome all of these drawbacks by circulating and refreshing the electrolyte continuously between the three units and using catalysts to increase the cathode potential during the discharge and decrease it during the charging process.