New Process Could Simplify Production of Oxide Nanowires for Lithium-Ion Batteries

An alloy of lithium and aluminum is being formed as the first step in the process. / Credit: Rob Felt, Georgia TechResearchers from the Georgia Institute of Technology have discovered a simple technique for producing oxide nanowires directly from bulk powders in ambient conditions.

These one-dimensional nanostructures have applications in lightweight structural composites, advanced sensors, electronic devices and separator membranes for lithium-ion batteries. The latter, specifically, could help enhance the safety and rate capabilities, while lowering the overall manufacturing cost, of lithium-ion batteries used in aircraft and motor vehicles.

Powder is dissolved in ethanol to start the reaction. / Credit: Rob Felt, Georgia Tech“Overall, this is a better technology for batteries, but until now, ceramic nanowires have been too expensive to consider seriously,” said Gleb Yushin, a professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. “In the future, we can improve mechanical properties further and scale up synthesis, making the low-cost ceramic separator technology very attractive to battery designers.” The technique, described in a paper in the journal Science, uses a solvent reaction between a bimetallic alloy of either lithium or magnesium and aluminum to form bundles of nanowires (nanofibers) when the reactive metal (lithium or magnesium) dissolves. The aluminum that’s left begins to form aluminum alkoxide nanowires growing perpendicular to the surface of the particles starting from the nuclei until the particles are completely converted. The alkoxide nanowires can then be heated in open air, using the hydrogen gas formed in the dissolution process as fuel, to form aluminum oxide nanowires and may be formed into paper-like sheets.

Georgia Tech professor Gleb Yushin, who led the research team that formed oxide nanowires from bulk powders. / Credit: Rob Felt, Georgia TechThe process is conducted at ambient temperature and pressure without the use of catalysts, toxic chemicals or costly processes such as chemical vapor deposition. The produced nanowires can be used to improve the electrical, thermal and mechanical properties of functional materials and composites, including battery membranes capable of withstanding temperatures greater than 1,000 degrees Celsius.
The research was supported by the National Science Foundation and California-based Sila Nanotechnologies and included Alexandre Magaskinski of Georgia Tech and Gene Berdichevsky of Sila Nanotechnologies, along with Yushin.