But according to existing research from the U.S. Army, the CFx chemical formula is "known to have one of the highest theoretical energy capacities compared to other popular lithium cell chemistries."
"It is based on the old theory and with the new design," ORNL's Liang said. "This is a big breakthrough."
During an experiment, the ORNL researchers developed and tested an actual CFx battery, but used a solid electrolyte to add more energy capacity. Current lithium-ion batteries have electrodes in the form of a positive cathode and a negative anode, and electrolytes in between so charged lithium ions can move around. When charging a battery, lithium ions move from a cathode to an anode for storage. In discharge, the lithium ions move from the anode to the cathode, and out to the device.
The new CFx battery design has a multipurpose electrolyte of solid lithium thiophosphate that can be an ion conductor and also serve as a cathode. The electrolyte can carry charge and hold ions, which helps boost the energy capacity of the battery. The prototype CFx battery has a solid electrolyte, while conventional batteries have liquid electrolytes, Liang said.
"You have an electrolyte that not only does its own job, it provides the function of the cathode," Liang said. "You can also store energy in the electrolyte."
The dual-functioning electrolyte could lead to new battery designs, and new batteries could be in the market in a few years, Liang said. He wasn't able to determine the cost of making such batteries.
"I have no idea of mass production and how much it's going to cost for each individual battery. All the material we use here is abundant.," Liang said.
ORNL researchers worked for three to four years on this battery technology and are researching new solid electrolyte materials, Liang said.
ORNL, based in Oak Ridge, Tennessee, is managed by University of Tennessee, Battelle.