The research was carried out by scientists at the PAcific Northwest National Laboratory. The research team found that by adjusting the volume of different additives in the electrolyte, they can develop lithium-ion batteries that can maintain good performance at temperatures from -40 ° C to 60 ° C.
This work focused on the use of different combinations of five electrolyte additives. It was found that there are three compound additives that can form the best combination. This combination can improve the discharge performance at -40 ° C and slightly improve the cycle stability at 60 ° C. At 25 ° C, the battery can maintain more than 85% of its capacity after 1,000 cycles. The research team described this method in a paper published in the Journal of the American Chemical Society Applied Materials and Interfaces, which builds a robust electrode / electrolyte interface that enables lithium-ion batteries to be used in a wide range of temperatures.
The performance improvement is attributed to the way that the electrolyte additives form a protective layer on the anode and cathode surfaces, which helps prevent the electrolyte from degrading during operation, and this protective layer made of materials with a wider melting point helps To increase the temperature range of the battery.
Lithium batteries and most other types of batteries lose performance and capacity in cold environments. Although it is rare that electric vehicles or energy storage batteries need to work at minus 40 ° C, expanding the overall temperature range of the battery is also conducive to improving battery performance at common temperatures.
The team's experiments focused on capsule cells based on nickel-cobalt-aluminum anodes and graphite cathodes, a chemical composition favored by Tesla and other battery manufacturers. But it is unclear whether the same additives can be used to improve the performance of other popular battery chemistries, such as lithium iron phosphate (LFP) or nickel-cobalt manganate (NMC).