Low-Cost Nanoporous Sol Gel Separators for Lithium-Based Batteries

70566 Lithium-based batteries for vehicles need to be longer lasting, faster recharging, able to deliver high power pulses, safer, higher energy density, and lower in cost. However, the commercial microporous plastic polymer separators used in these batteries are too expensive and are very limited in their ability to provide these needed performance improvements. This project will develop nanoporous sol gel coatings as a new type of separator that can be coated from a water-based solution at less than one-half the cost per square meter of commercial plastic separators. The non-flammable, ionic, and ultrathin properties of the sol gel separators would allow major improvements in the safety, recharging and discharging speeds, lifetime, and energy density of lithium-based batteries. In Phase I, tough but flexible sol gel separators will be designed to match or exceed the mechanical properties of commercial plastic separators. The ionic content of the sol gel separators will be increased to exceed the specific conductivity found with standard electrolytes and separators. Two processes for making the sol gel separators will be compared with respect to overall performance and low cost, before selecting a specific product design and manufacturing process. Commercial Applications and Other Benefits as described by the awardee: Besides providing separators for lithium-based batteries for vehicles, sol gel separators could be used for other lithium-based battery applications such as cell phones, as separator membranes for fuel cells, as optical waveguides for telecommunications, as ultrafiltration membranes for purifying water, as dye-sensitized sol gel coatings for solar splitting of water or methanol to produce hydrogen fuel, and as photoquality ink jet printing materials.