Metastable And Glassy Ionic Conductors
Demand for Lithium-ion (Li-ion) batteries has increased significantly as products such as smartphones, laptops, electric vehicles, and grid storage batteries rise in popularity. However, Li-ion batteries have numerous safety and performance limitations due to their flammable electrolyte and the charge storage density of their active materials, which are not easily overcome by incremental progress. New types of high-performance separators and electrodes built with solid-state ion conductors could simultaneously improve the energy density and safety of lithium ion batteries by removing the most flammable battery components, and also improving the driving range and durability of electric vehicles. Solid-state separators also open the door to the use of lithium metal as an active material, resulting in a significant increase in cell energy content, and the subject of research efforts for the past several decades. New battery technology that employs energy dense, thermally stable, and long-lasting materials will also be of interest for grid storage, particularly in dense, urban environments where the space occupied by storage systems is more of a concern.
Project Innovation + Advantages:
Oak Ridge National Laboratory (ORNL) will develop glassy Li-ion conductors that are electrochemically and mechanically stable against lithium metal and can be integrated into full battery cells. Metallic lithium anodes could significantly improve the energy density of batteries versus today’s state-of-the-art lithium ion cells. ORNL has chosen glass as a solid barrier because the lack of grain boundaries in glass mitigates the growth of branchlike metal fibers called dendrites, which short-circuit battery cells. The team aims to identify a glassy electrolyte with high conductivity, explore novel and cost-effective ways to fabricate this thin glass electrolyte, and design electrolyte membranes that are sufficiently robust to prevent cracking and degradation during battery fabrication and cycling. Advanced glass processing using rapid quench methods will enable a range of compositions and microstructures as well as their cost-effective fabrication as thin, dense membranes. In addition to glass composition, a range of membrane designs will be investigated by modeling and experiment. For efficient battery fabrication, the glassy membrane will likely require mechanical support and protection, which could be achieved by employing polymers or ceramic layers as a support.
If successful, developments made under the IONICS program will increase the energy storage content for vehicle batteries by about 30% compared to today's Li-ion batteries and significantly reduce battery storage system costs.
IONICS program innovations could contribute to energy storage solutions for transportation and the grid, lessening U.S. dependence on imported oil and improving grid resilience.
A 10% increase in electric vehicle use would reduce US oil consumption by 3% and reduce total US CO2 emissions by 1%.
IONICS program innovations could further establish U.S. businesses as technical leaders in energy storage, encouraging greater use of readily available renewable resources and increasing the competitiveness of electric vehicles.