Liquefied Gas Electrolytes for Electrochemical Energy Storage Devices

Wednesday, 4 October 2017: 12:00
Maryland D (Gaylord National Resort and Convention Center)
Y. Yang, C. S. Rustomji (University of California, San Diego), and Y. S. Meng (University of California San Diego)
Electrochemical energy storage devices, such as Li-ion batteries and electrochemical capacitors, have seen little change in their electrolyte chemistry since their commercialization. These liquid electrolytes often limit the energy density and low-temperature operation of these devices, which hinder many potential applications. Our work uses electrolytes based on solvent systems which are typically gaseous under standard conditions and show excellent performance in electrochemical energy storage devices. It is demonstrated that these novel solvents have excellent performance over an extended temperature range and a wide potential window of stability. Fluoromethane based electrolytes demonstrate a high coulombic efficiency for cycling dendrite-free lithium metal anodes. Lithium batteries show excellent low-temperature operation down to -60 °C with high capacity retention. Electrochemical capacitors, using difluoromethane based electrolytes, show outstanding performance and a wide operation temperature range from ‑78 to +65 °C with an increased operation voltage.