Liquefied Gas Electrolytes Allow Lithium Batteries to Operate at Very Low Temperatures
The innovative electrolytes also allow electrochemical capacitors to operate at temperatures of -80 °C, which at present operate at low temperatures of -40 °C. Apart from ensuring operation at very low temperatures, the technology also maintains greater performance at room temperature. The new electrolyte chemistry can enhance not only the energy density but also the safety of electrochemical capacitors and lithium batteries.
The research was published online in the Science journal on 15th June 2017.
The technology will enable electric vehicles in cold countries to cover greater distances on a single charge, thus eliminating range anxiety in winter months in cities such as Boston. The technology can also be applied to power crafts such as satellites, high atmosphere WiFi drones, interplanetary rovers, weather balloons and other aerospace applications under severe cold conditions.
The electrochemical capacitors and batteries created by the research team are specifically cold hardy as the electrolytes in them are formed of liquefied gas solvents (i.e. gases liquefied under moderate pressures) that are more resistant to freezing when compared to standard liquid electrolytes. Liquefied fluoromethane gas was used to synthesize electrolyte for the lithium battery. Liquefied difluoromethane gas was used to synthesize electrolyte for the electrochemical capacitor.
Meng also heads the Laboratory for Energy Storage and Conversion and is the director of the Sustainable Power and Energy Center, both located at UC San Diego.
“It is generally agreed upon that the electrolyte is the primary bottleneck to improve performance for next generation energy storage devices,” stated Cyrus Rustomji, and first Author of the study and a Postdoctoral Researcher in Meng’s group. “Liquid-based electrolytes have been thoroughly researched and many are now turning their focus to solid state electrolytes. We have taken the opposite, albeit risky, approach and explored the use of gas based electrolytes.”
The Researchers from UC San Diego are the pioneers in analyzing gas-based electrolytes for use in electrochemical energy storage devices. The futuristic application of this technology might be to power spacecraft for interplanetary exploration.