This Small Business Innovation Research Phase I Project focuses on improving lithium-air battery system, one of the most promising electrochemical power sources for energy storage application due to its highest theoretical energy density. The major technical issue which has been gradually unveiled over the last couple of years is electrolyte decomposition, which is likely the cause of poor round trip efficiency and cycle life which hamper the commercialization of this technology. So far most of the commonly used electrolyte solvents being tested are not stable in Li-air batteries. A few solvent candidates have shown improved stability, but they react with the lithium metal anode and/or show poor rate performance. Many researchers are working on finding new electrolyte candidates, which is challenging and time consuming. This proposal relies on an innovative approach, inspired by nature, via introducing a catalyst to shorten the half-life of the reactive intermediate to eliminate/reduce the root cause of electrolyte decomposition. This approach if successful will allow the access of current widely used electrolyte systems which have been studied for more than decades. The approach will improve the roundtrip efficiency and capacity retention and will open the opportunity for the commercialization of Li air batteries.
The Broad Impacts/Commercial Potential of This Project is believed to remove the major hurdle on aprotic Li-air battery system ? electrolyte decomposition and provide a longer cycle life and good round trip efficiency at a lower cost. Once the controlled manufacturing of the nano-sized catalyst and the mechanical processing of the material to produce a prototype electrode material for the energy storage cells are completed, the necessary foundation to consider a manufacturing technology program for the commercialization for energy storage applications such as solar, wind power and smart grid systems will have been provided.
Li-Air battery has the highest theoretical energy density among all the battery systems and is one of the most promising power sources for electric vehicle, electric grid and renewable energy storage applications. The commercialization of this technique is however hampered by its poor energy efficiency, i.e., large energy loss during charge and discharge cycle, and poor cycle life. Poor cycle life performance is due to the electrolyte decomposition. Here an innovative approach, adopted by nature, via using biocatalyst mimics to reduce the root cause of electrolyte decomposition and to improve the electrochemical efficiency, has been proposed and developed through this phase I period. The approach has shown 30% reduction in energy loss during cycling and 27% improvement in cycle life. We have developed methodology to produce the catalysis with desired particle size for optimum catalytic performance. We have also developed process technologies to introduce the catalyst to air electrode as well as in electrolyte. Both approaches have shown major battery performance improvement. The rate performance is also greatly improved. The Columbic efficiency at 0.5 milliamps per square centimeter increased from 50% to 90%. This finding opens the door for the commercialization of Li-Air battery which will have significant impact to the energy related applications.
