As interest in electric vehicles rises, some of their most pressing problems are brought to light more clearly. Two of the bigger 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 new kind of electrode that could unleash more power and enable quicker charging. They achieved this by using magnets to create thicker electrodes, the positively and negatively charged portions of the battery that provide power to a device. This method avoids common issues with sizing up these crucial components.
The end result is an electrode that, compared to a battery with a commercially available electrode, could let an electric car go twice as far on a single charge.
Because rapid charge transport only requires a few nanometers of thickness, two-dimensional materials are frequently seen as a promising candidate for high-rate energy storage applications, according to Guihua Yu, a professor in the Walker Department of Mechanical Engineering and Texas Materials Institute at UT Austin. But stacking nanosheets on top of each other as building blocks “can cause significant bottlenecks in charge transport, making it hard for next-generation, high-energy batteries with thick electrodes to be both high energy and fast to charge.”
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 create thickness, and their orientations are then controlled by a magnetic field. During the making of the electrode, the research team used common magnets to stack the two-dimensional materials vertically. This made a straight path for ions to travel through the electrode.
Typically, thicker electrodes make the ions move through the battery over longer distances, which results in a slower charging rate. The layers of material that make up an electrode are usually laid out horizontally. This makes the ions snake back and forth.
According to Zhengyu Ju, a graduate student in Yu’s research group who is in charge of this project, “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.”
They created a horizontally arranged electrode using 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 that their work in this area is still in its early stages. In this study, only one kind of battery electrode was examined.
Their objective is to generalize their vertically organized electrode layer methodology so that it can be used for various electrode types made of various materials. This could make more companies use the method, which could lead to batteries for electric cars that can be charged quickly but have a lot of energy.
Yu, Ju, Xiao Xu, Xiao Zhang, and Kasun U. Raigama are members of the research team from The University of Texas at Austin. Steven T. King, Kenneth J. Takeuchi, Amy C. Marschilok, Lei Wang, and Esther S. Takeuchi are members of the research team from Stony Brook/Brookhaven National Laboratory. The U.S. Department of Energy gave money for the study to the Center for Mesoscale Transport Properties, which is part of the Energy Frontier Research Center.
