Self-Forming Solid-State Batteries
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:
The University of California, San Diego (UC San Diego), in partnership with Liox Power and the University of Maryland, will develop a self-forming, high temperature solid-state lithium battery that solves the critical cost and performance problems impeding commercialization of solid-state batteries for electric vehicles. The battery will possess a very long life due to a chemical mechanism that repairs cycling damage automatically. This self-healing electrolyte will also limit the growth of dendrites. Dendrites are branchlike metal fibers that can grow to span the space between the negative and positive electrodes, thereby causing a short circuit. The team plans to reduce costs by designing a manufacturing process for forming solid-state electrolytes and cathodes in a single step by depositing a graded lithium/phosphorous/sulfur composite material as both the cathode and electrolyte. In theory, this composition should be able to remove any deformations due to dendrite formation by a simple thermal cycling process. A non-flammable polymer used within this composite will both add structural strength and eliminate the need for flammable liquid electrolytes. The team projects that the battery will cost half of current lithium-ion batteries while doubling the energy density.
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.