0748 GMT December 17, 2017
The technology could help make lithium ion batteries safer and more efficient, as well as boost the range of electric vehicles during cold winter months, according to UPI.
The new batteries could also power vehicles and instruments operating in extreme cold, like space rovers, satellites and high-altitude weather balloons.
The electrolytes are composed of liquefied gas solvents. Many gases require extreme pressure to liquefy. Gases that liquefy at moderate pressures are less apt to freeze.
To create their battery's electrolyte, researchers liquefied fluoromethane gas. For the capacitor electrolyte, scientists liquefied difluoromethane gas.
Shirley Meng, a nanoengineering professor at UCSD, said, "Better batteries are needed to make electric cars with improved performance-to-cost ratios.
“And once the temperature range for batteries, ultra-capacitors and their hybrids is widened, these electrochemical energy storage technologies can be adopted in many more emerging markets."
Electrolytes have been identified as one the main barriers inhibiting efficiency improvements in lithium ion battery technology.
Many researchers have abandoned liquid electrolytes in favor of battery model using solid state electrolytes.
Cyrus Rustomji, a postdoctoral researcher at UCSD, said, "We have taken the opposite, albeit risky, approach and explored the use of gas based electrolytes.”
Aside from efficiency, one of the biggest problems with lithium ion batteries is their tendency to catch on fire.
When electrolytes overheat, they can trigger a chemical chain reaction that generates extreme temperatures inside the battery.
The liquefied gas electrolytes limit this risk, ensuring internal temperatures remain moderate.
The electrolyte works like an emergency off switch.
Rustomji said, "As soon as the battery gets too hot, it shuts down. But as it cools back down, it starts working again. That's uncommon in conventional batteries."
Additionally, the electrolyte's unique chemical makeup prevent the buildup of lithium metal on the battery's electrodes.
Inside commercial lithium ion batteries, lithium deposits called dendrites can grow like tiny stalagmites, eventually piercing battery components and causing the circuitry to short out.
Researchers hope to continue improving their battery's efficiency and low-temperature abilities. They detailed their most recent electrolyte breakthrough in the journal Science.