At the Spring 2015 Materials Research Conference in San Francisco, Pathion, Inc. presented new advancements in solid-state electrolytes that perform up to four times better than existing lithium-ion technologies - and with a high degree of safety. "The lithium-ion battery industry has recently been plagued with bad press due to highly publicized fires in the automotive sector and on airplanes." said Pathion Chairman and CEO, Mike Liddle. "Our researchers have presented new derivatives of our LiRAP™ solid-state electrolyte that not only deliver safe, non-flammable batteries, but also provide a path to more than 1,000 Watt-hours/kilogram (Wh/kg) of energy density."
The presentations describe derivatives built upon LiRAP (Lithium-Rich Anti-Perovskite), a solid electrolyte. Pation has an exclusive worldwide license for LiRAP from Los Alamos National Laboratories. Supported by an ARPA-E grant, LiRAP has proven to be a safe alternative compared to the liquid electrolytes used in most of today’s lithium-ion batteries. “Pathion’s focus has been on the development of advanced materials over the last five years. These new electrolyte formulations have come from our research, and represent some of the most important breakthroughs in safe high energy density batteries in recent memory. Pathion is delighted to have added to its IP portfolio,†said Liddle.
The first presentation described the role of LiRAP in a solid-state lithium-sulfur electrolyte. Solid-state electrolytes, unlike liquid-state, have (1) extremely low expansion, (2) no out-gassing, and (3) the elimination of dendrite growth between anode and cathode. One or more of these three phenomena causes explosion or fire in lithium-ion batteries. The lithium-sulfur electrolyte employs a doped/optimized glass electrolyte - a solid material.
Also presented was a highly-efficient sulfur cathode. In combination, this cathode and electrolyte have resulted in a significant improvement in charge efficiency with a longer cycle life. Such a lithium-sulfur battery could achieve specific energy levels up to 800 Wh/kg, while the best lithium-ion cells today deliver only about 250 Wh/kg. In addition, the new lithium-sulfur-based material can operate as either a battery or a supercapacitor - a major breakthrough in itself whose applications could be very exciting.
In the second presentation, sodium-ion battery cells are described, and recent work demonstrates extraordinary performance. Addressing safety issues directly by again substituting a liquid electrolyte with a solid – Pathion’s LiGlass™. On a performance basis, LiGlass exhibits ultrafast ionic conductivities at room temperature and up to 200 degrees C - which can lead to energy densities that comfortably exceed 1,000 Wh/kg. These characteristics will enable the creation of a very wide range of new applications. LiGlass has been replicated in the labs at the University of Texas.
Pathion technology executive Andy Murchison led these efforts with the support of Helena Braga and Jorge Ferreira of the University of Porto, who were operating under a work-for-hire agreement with Pathion. The breakthroughs - Pathion lithium-sulfur electrolyte and LiGlass - continue to be in a developmental state.
