As interest in electric vehicles rises, some of their most pressing problems are brought to light more clearly. Two of the main issues facing electric vehicles are being addressed by researchers at The University of Texas at Austin: limited range and slow recharging.
For lithium-ion batteries, the researchers created a novel kind of electrode that could unleash more power and enable quicker charging. They achieved this by making the electrodes the positively and negatively charged sections of the battery that supply energy to a device thicker and using magnets to align them in a special way that avoids the usual issues with sizing up these crucial portions.
The end result is an electrode that, in comparison to a battery utilizing an existing commercial electrode, may enable an electric vehicle to travel twice as far on a single charge.
“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.”
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.
Zhengyu Ju
The discovery’s key element, described in the Proceedings of the National Academy of Sciences, makes use of thin, two-dimensional materials as the electrode’s building blocks. These materials are stacked to generate thickness, and their orientations are then controlled by a magnetic field.
The two-dimensional materials were arranged vertically by the study team during the production process using readily accessible magnets, resulting in a direct path for ions to move through the electrode.
Typically, thicker electrodes make the ions pass through the battery over longer distances, which results in a slower charging rate. The ions are forced to snake back and forth by the electrode’s characteristic horizontal alignment of the layers of material that make up the electrode.
“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.
They created a horizontally organized electrode utilizing the same materials as their own electrode as an experimental control in addition to comparing it to a commercial electrode. In comparison to the horizontal electrode, which took 2 hours and 30 minutes to recharge, the vertical thick electrode was able to reach 50% of its initial energy level in just 30 minutes.
The researchers emphasized they are early in their work in this area. They looked at just a single type of battery electrode in this research.
Their objective is to generalize their vertically arranged electrode layer technology so that it may be used for various electrode types made of various materials. This may encourage broader industrial adoption of the method, opening the door for future fast-charging yet high-energy batteries that drive electric vehicles.
The research team includes, from The University of Texas at Austin: Yu, Ju, Xiao Xu, Xiao Zhang, and Kasun U. Raigama; and from Stony Brook/Brookhaven National Laboratory: Steven T. King, Kenneth J. Takeuchi, Amy C. Marschilok, Lei Wang and Esther S. Takeuchi. The research was funded by the U.S. Department of Energy through the multi-institutional Energy Frontier Research Center, the Center for Mesoscale Transport Properties.
