Membranes for Solid State Lithium Batteries

Low-cost, safe, large voltage (i.e., hundreds of volts), and high-energy lithium-ion batteries with long calendar and operational lives are required for a variety of electric utility applications to address issues associated with power quality and transmission congestion. Such large-format batteries also are needed for vehicle applications (e.g., electric and hybrid electric vehicles). For both applications, these large voltage batteries need to be fabricated in the bipolar configuration to reduce overall cost. In turn, this requires the use of solid electrolytes. However, state-of-the-art Li-ion batteries primarily use either liquid or gel electrolytes, which are toxic and flammable. Existing solid electrolytes do not meet the performance requirements. This project will develop a solid polymer nanocomposite electrolyte system that can exhibit high Li-¬ion conductivity at low temperatures, including room temperature, along with good mechanical properties. The approach involves tailoring the microstructure of the nanocomposite, varying the concentration of the nanocrystalline phase, and exploring different types and amounts of lithium salts. The nanocomposite membranes will be fabricated using standard polymer processing methods and characterized for Li-ion conductivity and transference number. Commercial Applications and other Benefits as described by the awardee: Successful implementation of the proposed technology should lead to safe and cost-effective large voltage batteries for electric and hybrid electric vehicles, and for telecommunication and electric utility applications. The lithium-ion batteries should find use in other consumer and industrial applications as well.