Researchers have taken a step forward in developing batteries that can store 10 times more energy than existing lithium-ion batteries.
The scientists have been experimenting with a "garnet ceramic" material called LLZO that could hasten the release of batteries based on lithium-air chemistry. Lithium-air batteries have been in development for decades but are considered unstable for practical use.
LLZO could lead to batteries that are safer, denser and more longer-lasting than lithium ion. Researchers tested its properties using electron microscopy at the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL).
Conventional lithium-ion batteries have reached their limits and a new chemistry is needed to advance the state of the art, said Cheng Ma, a post-doctoral associate researcher at ORNL.
"You have to adopt something radically different, and that's the lithium-air battery," Ma said.
Lithium-air batteries are more practical for use in cars and power grids and less so in laptops and mobile devices, because of the chemistry and density levels, Ma said.
LLZO effectively stabilizes the lithium-air battery -- itself is a proof-of-concept technology -- and moves it closer to practical use. Researchers haven't tested LLZO with actual batteries yet, but applied researchers can now take the research and put it to work, Ma said.
The research was published in the Angewandte Chemie journal.
Lithium-ion batteries have electrodes -- a positive cathode and a negative anode -- with electrolytes in between that allow charged lithium ions to move around. During a charge, lithium ions move from the cathode to the anode for storage. The reverse happens during a discharge, with the lithium ions moving from anode to cathode and out to the device using the battery.
Lithium-air batteries are different in that they use an aqueous electrolyte and lithium anode, That provides greater energy density, but the current materials aren't stable, making lithium-air batteries im practical. But LLZO acts as a separator and keeps the battery stable, especially during discharge.
LLZO could be better than any commercial electrolyte for lithium-air batteries, Ma said. It also gives options for scientists to chase new ideas in lithium-air battery designs.
"It gives an option to realize the stable operation of lithium air battery," Ma said.