A new fabrication technique developed by materials science researchers at the Georgia Institute of Technology could allow solid-state car lithium-ion batteries to use non-flammable ceramic electrolytes – meaning safer, lighter, and more energy-dense batteries. Its manufacture could use the same production processes as in batteries made with conventional liquid electrolytes, saving vast amounts of time and money. You can also start your own business by getting an LLC in Georgia.
The melt-infiltration technology is a one-step process. It uses electrolyte materials that can be infiltrated into porous but densely packed, thermally stable electrodes. The result is “high-density composites based on pressure-less, capillary-driven infiltration of a molten solid electrolyte into porous bodies, including multilayered electrode-separator stacks.”
Gleb Yushin, a professor at Georgia Tech’s School of Materials Science and Engineering, explained:
“While the melting point of traditional solid-state electrolytes can range from 700 degrees Celsius to over 1,000 degrees Celsius, we operate at a much lower temperature range, depending on the electrolyte composition, roughly from 200 to 300 degrees Celsius. At these lower temperatures, fabrication is much faster and easier. Materials at low temperatures don’t react. The standard electrode assemblies, including the polymer binder or glue, can be stable in these conditions.”
The patent-pending manufacturing technology can rapidly generate high-quality multilayered cells of any shape or size at scale using proven possesses and tools optimized over the last three decades for Li-ion. It mimics the low-cost fabrication of commercial Li-ion cells with liquid electrolytes but uses solid-state electrolytes with low melting points instead. The breakthrough should facilitate the spread of solid-state batteries and allow electric car manufacturers to spend less on cooling systems, saving them even more in material, dimensions, and weight.
Yiran Xiao, a Georgia Tech graduate student, explained:
“Melt-infiltration technology is the key advance. The cycle life and stability of Li-ion batteries depend strongly on the operating conditions, particularly temperature. If batteries are overheated for a prolonged period, they commonly begin to degrade prematurely, and overheated batteries may catch fire. That has prompted nearly all-electric vehicles (EV) to include sophisticated and rather expensive cooling systems.”
Kostiantyn Turcheniuk, a co-author and Georgia Tech research scientist notes that higher-density cells support longer driving ranges:
“The developed melt-infiltration technology is compatible with a broad range of material chemistries, including so-called conversion-type electrodes. Such materials have been demonstrated to increase automotive cell energy density by over 20% now and by more than 100% in the future.
When the automotive industry is ready to jump towards solid-state batteries, the one discovered in Georgia will be the only viable production method for a matter of simplicity, speed, and containment costs.”
The team’s technique isn’t commercially ready yet, but soon. Battery cell prices need to drop below $70 per kilowatt-hour before the consumer electric vehicle market can fully open, and battery innovations such as this are critical for that. At the moment, cell prices are at US$100 per kilowatt-hour.
At the moment, Toyota may be leading the push for EVs equipped with fluoride-ion solid-state batteries. It plans to debut a prototype car with a fast-charging solid-state battery this year.
