Photos by David Baillot/UC San Diego Jacobs School of Engineering
When it comes to battery developments, there’s no shortage of news. From a battery design that can last up to 100 years to a water-powered battery that manufactured at half the cost of a lithium-ion battery, there always seems to be something new & exciting happening in field. When it comes to battery developments, there’s no shortage of news. From a battery design that can last up to 100 years to a water-powered battery that manufactured at half the cost of a lithium-ion battery, there always seems to be something new & exciting happening in field.
Engineers at the University of California, San Diego designed a new high-energy-packed lithium-ion battery that performs optimally in freezing and scorching hot temperatures, according to a statement by institution released. Engineers at the University of California, San Diego designed a new high-energy-packed lithium-ion battery that performs optimally in freezing and scorching hot temperatures, according to a statement by institution released.
Operations at extreme temperatures
“You need to operate at high temperatures in areas where ambient temperatures can reach triple digits and the roads get hotter. In electric vehicles, the battery is often under the floor near to those hot roads,” explains Zheng Chen, professor of nano engineering at UC San Diego Jacobs School of Engineering and lead author of the study.“You need to operate at high temperatures in areas where ambient temperatures can reach triple digits and the roads get hotter. In electric vehicles, the battery is often under the floor near to those hot roads,” explains Zheng Chen, professor of nanoengineering at UC San Diego Jacobs School of Engineering and lead author of the study.
The batteries warm-up when the current is flowing through during operation. If the batteries cannot tolerate this warm-up at high-temperature, their performance will quickly. ”The batteries warm-up when the current is flowing through during operation. If the batteries cannot tolerate this warm-up at high-temperature, their performance will quickly.”
Chen’s team conducted tests with the prototype batteries and found that they retained 87.5% & 115.9% of their energy capacity at -40 & 122 F (-40 and 50 C), respectively. Even better, the researchers report that the prototypes have a high Coulomb efficiency of 98.2% & 98.7% at these temperatures, means the battery can go through many charge and discharge cycles before they cease to function. Chen’s team conducted tests with the prototype batteries and found that they retained 87.5% & 115.9% of their energy capacity at -40 & 122 F (-40 and 50 C), respectively. Even better, the researchers report that the prototypes have a high Coulomb efficiency of 98.2% & 98.7% at these temperatures, means the battery can go through many charge and discharge cycles before they cease to function.
However, developing new batteries is not an easy task. However, developing new batteries is not an easy task.
“If you want a high energy density battery, you often have to use very harsh and complex chemistry,” says Chen. “High energy means more reactions, which means less stability, more degradation. Making a stable high-energy battery in itself is a difficult task. Trying to do it over a wide temperature range is even more difficult. “If you want a high energy density battery, you often have to use very harsh and complex chemistry,” says Chen. “High energy means more reactions, which means less stability, more degradation. Making a stable high-energy battery in itself is a difficult task. Trying to do it over a wide temperature range is even more difficult.
Engineering a dibutyl ether electrolyte
To overcome these obstacles, the team invented the dibutyl ether electrolyte and engineered the sulfur cathode to be more stable by grafting it to a polymer that prevents more sulfur from dissolving into the electrolyte. To overcome these obstacles, the team invented the dibutyl ether electrolyte and engineered the sulfur cathode to be more stable by grafting it to a polymer that prevents more sulfur from dissolving into the electrolyte.
The end result was batteries with much longer cycling-lives than a typical lithium-sulfur battery. “Our electrolyte helps improve both the cathode & anode sides while providing high conductivity & interfacial stability,” said Chen. The end result was batteries with much longer cycling-lives than a typical lithium-sulfur battery. “Our electrolyte helps improve both the cathode & anode sides while providing high conductivity & interfacial stability,” said Chen.
The new batteries could now allow EVs to travel further in cold climates on a single charge, while reducing the need for cooling systems to prevent vehicle battery packs from overheating in hot climates. But first, the team needs to expand the battery’s chemistry, optimize it to operate at even higher temperatures, and further extend its cycle life. The new batteries could now allow EVs to travel further in cold climates on a single charge, while reducing the need for cooling systems to prevent vehicle battery packs from overheating in hot climates. But first, the team needs to expand the battery’s chemistry, optimize it to operate at even higher temperatures, and further extend its cycle life.
The study is published in the Proceedings of the National Academy of Sciences (PNAS).
