Researchers have developed a low-electrolyte lithium-ion metal battery that retains a significant percentage of its capacity at extremely low temperatures.
Researchers are working to improve the lithium-ion battery, and one promising option is to build a version that uses pure lithium metal at the anode, unlike current ion-lithium batteries. Researchers have made significant progress in this area with new research Achieved And they managed to make a version that uses weak bonds in its electrolytes, which brings unprecedented performance in cold weather.
The reason for the researchers’ interest in lithium batteries is the extraordinary energy density of pure lithium metal anodes compared to current batteries that use a combination of graphite and copper. This advantage is so significant that some researchers refer to lithium as a “dream material” and others find it necessary to use it to break down the energy density ceiling of current batteries.
Researchers at the University of California, San Diego, were looking to build a new battery that could charge and discharge at extremely low temperatures, focusing on the electrolyte. Their goal was to make an electrolyte that did not freeze and could continue to move lithium ions between the electrodes in cold weather.
The researchers tested two types of electrolytes: one that formed a strong bond with the ions and another that formed a much weaker bond. They found that the ability of the electrolyte to release ions affects battery performance at low temperatures.
The test cell, which had a strongly bonded electrolyte, failed after only two cycles at minus 60 ° C. The cell had a weakly bonded electrolyte but still maintained 76 percent of its capacity after 50 cycles and 84 percent of its capacity when the temperature dropped to minus 40 degrees.
“We found that the bond between lithium ions and the electrolyte and the structures that the ions found in the electrolytes determined the death or life of the battery at low temperatures,” said John Holoubek, lead author.
Further studies showed that the ions found a more regular arrangement at the anode with a weak electrolyte bond, but in the version with a strong electrolyte bond, the ions formed an irregular, needle-shaped arrangement. These bumps are called “dendrite”. Dendrites are another limitation for researchers in developing lithium metal batteries, as they quickly cause short circuits and battery failures.
“How lithium ions interact with the electrolyte at the atomic level not only leads to a stable cycle at very, very low temperatures, but also prevents the formation of dendrites,” said Zheng Chen, another co-author of the study.
Based on the findings of this study, the researchers weakly bonded a prototype of a lithium metal battery with a sulfur-based cathode and electrolyte. This battery can be used in harsh environments such as space or deep oceans, where extremely low temperatures make it necessary to use heating devices to prevent battery failure.
Findings of this research in the journal Nature Energy It has been published.