An artist’s illustration of a magnetic field boosting a thick electrode for lithium-ion batteries. Image: The University of Texas at Austin.As electric vehicles grow in popularity, the spotlight shines more brightly on some of their remaining major issues. Researchers at the University of Texas at Austin (UT Austin) are tackling two of the bigger challenges facing electric vehicles: limited range and slow recharging.
The researchers have fabricated a new type of electrode for lithium-ion batteries that could unleash greater power and faster charging. They did this by creating thicker electrodes – the positively and negatively charged parts of the battery that deliver power to a device – using magnets to create a unique alignment that sidesteps common problems associated with sizing up these critical components. The result is an electrode that could potentially double the range of an electric vehicle on a single charge, compared with a battery using an existing commercial electrode.
“Two-dimensional materials are commonly believed as a promising candidate for high-rate energy storage applications because it only needs to be several nanometers thick for rapid charge transport,” said Guihua Yu, a professor in UT Austin’s Walker Department of Mechanical Engineering and Texas Materials Institute. “However, for thick-electrode-design-based, next-generation, high-energy batteries, the restacking of nanosheets as building blocks can cause significant bottlenecks in charge transport, leading to difficulty in achieving both high energy and fast charging.”
As the researchers report in a paper in the Proceedings of the National Academy of Sciences, they created their thick electrodes by stacking two-dimensional materials and then using a magnetic field to manipulate their orientations. With commercially available magnets, they arranged the two-dimensional materials in a vertical alignment, creating a fast lane for ions to travel through the electrode.
Typically, thicker electrodes force the ions to travel longer distances through the battery, which leads to slower charging time. The typical horizontal alignment of the layers of material that make up the electrode force the ions to snake back and forth.
“Our electrode shows superior electrochemical performance partially due to the high mechanical strength, high electrical conductivity and facilitated lithium-ion transport thanks to the unique architecture we designed,” said Zhengyu Ju, a graduate student in Yu’s research group who is leading this project.
In addition to comparing their electrode with a commercial electrode, the researchers also fabricated a horizontally arranged electrode using the same materials for experimental control purposes. They were able to recharge the vertical thick electrode to 50% energy level in 30 minutes, compared with two hours and 30 minutes for the horizontal electrode.
The researchers emphasized that this work is still at an early stage. They looked at just a single type of battery electrode in this research.
Their goal is to generalize this methodology of vertically organized electrode layers by applying it to different types of electrodes using other materials. This could help the technique become more widely adopted by industry, leading to a future of fast-charging yet high-energy batteries for powering electric vehicles.
This story is adapted from material from the University of Texas at Austin, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.