A research team from the University of Maryland Energy Research Center (UMERC) has been awarded $1 million in NASA funding for its Garnet Electrolyte Based Safe, Lithium-Sulfur Energy Storage project, a game-changing battery technology that could potentially power future space missions.

The all solid-state battery, developed by A. James Clark School of Engineering faculty members Eric Wachsman, Liangbing Hu, and Chunsheng Wang, is a triple threat, solving the typical problems that trouble existing lithium-ion batteries: safety, performance, and cost.

"This all solid-state technology really changes everything, as it addresses all of the concerns we have about batteries today, and has brought the University of Maryland to the cutting-edge of battery research," said Wachsman, who serves as the director of UMERC and a professor in the Department of Materials Science and Engineering.

Lithium-ion batteries, which typically contain a liquid organic electrolyte, can catch fire under certain conditions, as shown by reported laptop and electric vehicle battery fires and even the temporary grounding of the Boeing 787 fleet for a series of battery fires. The research team's use of a solid-state ceramic electrolyte eliminates that risk.

"Lithium-ion batteries are used in everything from consumer electronics such as cell phones and laptops to electric vehicles," said Hu, an assistant professor of materials science and engineering. "This technology is safer than existing liquid-based lithium-ion batteries, and offers a much higher energy density."

Through his work on fuel cells, Wachsman has created and perfected low-cost ceramic fabrication techniques, demonstrating the ability to fabricate thin-film ceramic battery electrolytes with very low resistance. The high stability of these garnet ceramic electrolytes enabled the team to use metallic lithium anodes, which contain the greatest possible theoretical energy density and are considered to the holy grail of batteries.

Combined with high capacity sulfur cathodes, this all solid-state battery technology offers a potential unmatched energy density that far outperforms any lithium-ion battery currently on the market, making this technology uniquely capable of meeting NASA's goal of reducing mass required to store electrical power in space.

"In addition to its intrinsic safety, another unique feature of our solid-state garnet lithium-sulfur battery is that the dense garnet electrolyte can prevent the shuttle reaction of sulfur cathodes and dendrite of lithium anodes, allowing the realization of high energy lithium-sulfur chemistry," said Wang, who is an associate professor in the Department of Chemical and Biomolecular Engineering. This dramatically improves the longevity for lithium-sulfur batteries.

The team's Phase I award last year supported proof-of-concept research that demonstrated the technology's performance and reliability. Now in Phase II of NASA's Game Changing Development (GCD) program, Wachsman, Hu, and Wang will focus on optimizing the cell structure and scaling up its size to a commercially viable format. In 2016, the team will submit a proposal for up to $2 million in Phase III funding to make a full-scale prototype designed to achieve NASA's ultimate goal of sending these batteries into space.

The technology was born from Wachsman and Hu's solid-state battery project, in collaboration with University of Calgary associate professor Venkataraman Thangadurai, funded by the U.S. Department of Energy Advanced Research Projects Agency - Energy (ARPA-E). In 2014, Wachsman, Hu, and Thangadurai won the University of Maryland Invention of the Year Award in the physical sciences category for this solid-state battery technology.