UC San Diego

The escalating demand for electric vehicles and importable devices has uncovered the potential of lithium-ion batteries. However, the dendrite growth concern and poor low-temperature performance of the carbonated electrolyte cannot satisfy the wide application of the electrical devices. The advent of Liquefied gas electrolytes has proven to be one of the most promising alternatives to extend the temperature operation range of commercial rechargeable batteries to extremely cold conditions and eliminate the dendrite growth for long-term cycling. In this work, the mechanism of the liquefied gas electrolytes, especially its low-temperature mechanism has been explored and the solution to lower its inside pressure is also investigated. In this first part, a new liquefied fluoromethane electrolyte with the additive is shown to be competitive for low-temperature primary Li/CFx system compared with SOA. In the second part, the liquefied gas electrolyte is counteracted by its high vapor pressure, prohibiting its practical application. Herein, we construct a mimetic “brick-and-mortar” microstructure of MOF-polymer membrane, which enables the capillary condensation effects to effectively liquefy hydrofluorocarbon gas molecules in lithium cells under reduced pressure. This strategy opens a pathway to liquefying hydrofluorocarbon molecules under ambient pressure for the fabrication of lithium cells using gaseous solvents like the way in conventional liquid cell fabrication.