Solid improvement in battery power
28 Jan 2013
ORNL research has paved the way for larger and safer lithium ion batteries.
Scientists at Oak Ridge National Laboratory have developed the first high-performance, nanostructured solid electrolyte for more energy-dense lithium ion batteries.
Today’s lithium-ion batteries rely on a liquid electrolyte, which can entail safety issues because of its flammability.
“To make a safer, lightweight battery, we need the design at the beginning to have safety in mind,” said ORNL’s Chengdu Liang. “We started with a conventional material that is highly stable in a battery system - in particular one that is compatible with a lithium metal anode.”
The ability to use pure lithium metal as an anode could ultimately yield batteries five to 10 times more powerful than current versions, which employ carbon based anodes.
Lithium anode could lead to batteries five to 10 times more powerful than current versions
The ORNL team developed its solid electrolyte by manipulating a material called lithium thiophosphate so that it could conduct ions 1,000 times faster than its natural bulk form.
The researchers used a chemical process called nanostructuring, which alters the structure of the crystals that make up the material. The materials synthesis and characterisation were supported by the Center for Nanophase Materials Sciences at ORNL.
“Think about it in terms of a big crystal of quartz vs. very fine beach sand,” said co-author Adam Rondinone. “You can have the same total volume of material, but it’s broken up into very small particles that are packed together.
“It’s made of the same atoms in roughly the same proportions, but at the nanoscale the structure is different. And now this solid material conducts lithium ions at a much greater rate than the original large crystal.”
The researchers are continuing to test lab scale battery cells, and a patent on the team’s invention is pending.
