Thin Film Nasicon Solid Electrolyte Membrane for 3D Aqueous Na-Air Battery

According to the Intergovernmental Panel on Climate Change, the world needs to cut its carbon emissions by 50% by 2030 and 100% by 2050 to avoid the devastating effects of climate change. To hit these targets will require a transition away from fossil fuels and massive investments in renewable energy and energy storage. Unfortunately, the future use of Li-ion battery technology, the current leading energy storage technology, is threatened by resource and supply chain constraints on metals such as nickel and cobalt. As such, there is a need for higher energy, faster charging, lower cost batteries made with abundant materials to decarbonize the world. A promising alternative is the aqueous Na-Air battery with a practical energy density of 500 Wh/kg at the cell level made with abundant elements like sodium and water from the ocean and oxygen from the air that is free. The main limitation is that the battery’s Nasicon ceramic solid electrolyte is too brittle for handling thin samples and that thickening of the materials raises the cell resistance so much it makes charging and discharging too slow to be practical. The other limitation is that Nasicon is not resistant to highly caustic alkaline solution. To address these issues, this project is developing a thin, flexible, mechanically, and electrochemically stable Nasicon solid electrolyte that is resistant to highly caustic attack. Phase I work will involve the development of a thin film Nasicon solid electrolyte membrane and the demonstration of the technology in an aqueous Na-Air battery to evaluate its cycle life performance. When the project is completed and carried over to Phases II and III, electric utilities and electric vehicle manufacturers will benefit from lighter weight, faster charging batteries with a vastly simpler supply chain that lowers the battery’s floor costs below that of Li-ion. In the long term, large capacity, affordable batteries will also benefit solar and wind farms, by allowing for the storing excess energy for when it is needed, resulting in more sustainable energy use and thus lower associated carbon emissions. Additionally, batteries stored at homes, neighborhoods and office buildings would lead to a decentralized grid that is far more resilient to blackouts