No fear of cold shutdown, the new lithium battery cold environment can also operate efficiently

A major breakthrough in the field of electrolytic chemistry, published in the latest edition of the journal Science, is that American scientists have used liquefied gas for the first time to replace electrolytes, allowing lithium batteries and super-capacitors to operate efficiently at minus 60 °C and minus 80 °C, respectively. The new technology not only improves the mileage of single-charge electric vehicles in the cold winter, but also provides electricity for drones,specials, and interstellar detectors in extremely cold environments.

The scientific community generally believes that electrolytes are the biggest bottleneck for improving the performance of energy storage devices. Liquid electrolytes are already at the limit of research, and many scientists are now focusing on solid electrolytes. But Professor Mengying, director of the Center for Sustainable Electricity and Energy and the energy storage and Conversion Laboratory at the University of California, San Diego, led his team in the opposite direction, studying gaseous electrolytes and making breakthroughs. These gaseous electrolytes can be liquid under certain pressures and are more resistant to freezing.

In the new study, they selected two liquefied gases, fluoromethane and difluoromethane, from a large number of gas candidates to make electrolytes for lithium batteries and super-capacitors, respectively, so that the minimum operating temperature of lithium batteries extends from minus 20 °C. At minus 60 ° C, the operating temperature of the super-capacitor extends from minus 40 ° C to minus 80 ° C. Moreover, these electrolytes remain in an efficient state of operation after returning to normal room temperature.

In addition to creating low temperature work records, these gaseous electrolytes also overcome the common thermal runaway problems in lithium batteries and have a more secure advantage. Heat runaway is a vicious circle of heat in the battery. When the battery works, the temperature rises and a series of chemical reactions are initiated. The heat generated by these reactions in turn further heat the battery and cause it to expand and destroy. But gaseous electrolytes, at temperatures above room temperature, activate a natural shutdown mechanism that causes the battery to lose its conductivity and stop working, thus preventing the battery from overheating.

The latest research has also overcome another challenge of the short life of lithium batteries. Due to its light weight and ability to store more charges, lithium metal is recognized as the ultimate electrode material, but lithium reacts with traditional electrolytes, forming needle-like protrusions on the surface of the electrode, separating the battery and causing short circuits, resulting in the number of charges and discharges. Too little. The new electrolyte will not form a protrusion, greatly extending the battery life.

The researchers say the next step is to achieve the goal of lithium batteries operating at lower temperatures(minus 100 °C), providing new technology for deep space probes such as Mars and even Jupiter and Saturn.

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