Li-air batteries are promising alternatives to current Li-ion batteries due to the high specific energy of lithium metal (12 kWh kg-1) and the infinite oxygen for the cathode available from the ambient. However, even if the specific energy achieved in practice is much lower than the theoretical value (less than 10% of its theoretical value), the specific energy of Li-air batteries achieved in laboratory studies is at least 2-5 times higher than that of Li-ion batteries. Thus, developing the science and the technology to achieve values closer to the maximum achievable is an important objective.
The low values achieved for the specific energy of a Li-air battery is partly related to the low mass transfer coefficient of the porous cathode electrode. In the proposed effort, an innovative and active Li-air battery is proposed that has a much higher specific energy and power. The innovation lies in the development of an inter-digitated micro channel system adjacent to the cathode through which electrolyte and oxygen mixture is circulated. The hypothesis is that the specific energy and power of Li-air batteries is enhanced because the convection of electrolyte in the porous electrode can increase the mass flux of oxygen and lithium ion in the electrode. In addition, an improved thermal management system with the circulation of electrolyte, within and outside the battery electrode is proposed enabling the battery system to operate under extreme environmental conditions
The newly proposed battery is expected to have a specific energy as high as 600 Wh kg-1, and a specific power as high as 25 W kg-1. Thus, the project will lead to Li-air batteries with enhanced specific energy and power. The application domains include automotive, energy-storage, aerospace and others.
