With recent research from Rensselaer Polytechnic Institute published in Nature Communications, it is now possible to create a lithium-ion battery that can charge in a matter of minutes and still operate at a high capacity. With this new development, there is potential for battery performance to improve for consumer electronics, solar grid storage, and electric vehicles.
Like lithium ions move between two electrodes called a cathode and an anode, the lithium-ion battery also charges and discharges. A conventional lithium-ion battery will have the anode made of graphite and the cathode composed of lithium cobalt oxide.
The lithium-ion batteries are now increasingly becoming popular since these materials perform well together, but Rensselaer's researchers believe that they can enhance the function further.
The corresponding author of the paper and professor of mechanical, aerospace, and nuclear engineering at Rensselaer, Nikhil Koratkar, said that the way to make batteries better is to improve the materials used for the electrodes. Speaking further, Koratkar added that what they are attempting is to make lithium-ion technology even better in performance.
The potential of VS2 has given way for excitement, and it has been growing in recent years, but until now, researchers are facing the challenge of its instability, a characteristic that would lead to short battery life. The Rensselaer researchers had not only established the reason for that instability, but they had also developed a way to combat it.
Among the team were Vincent Meunier, head of Department of Physics, Applied Physics and Astronomy, and others. They determined that lithium insertion caused an asymmetry in the spacing between Peierls distortion, vanadium atoms, which was responsible for the breakup of the VS2 flakes. Also in their discovery was that covering the flakes with a nanolayered coating of titanium disulfide (TiS2), a material that does not Peierls distort, would stabilize the VS2 flakes and improve their performance within the battery.
When they solved the problem, the team found that the VS2-Ti2 electrodes could operate at a high specific capacity, or store plenty of charge per unit mass. Koratkar added that vanadium and small size and weight of sulfur allow them to deliver a high capacity and energy density. Their small size would also contribute to a compact battery.
Though it charges more quickly, the capacity didn't dip as significantly as it often does with other electrodes. The electrodes have the capacity of maintaining a reasonable power since unlike cobalt oxide, the VS2-TiS2 material is electrically conductive.
There appear to be multiple applications for this discovery in improving car batteries, power for portable electronics, and solar energy storage where high capacity is essential but increased charging speed would also be attractive.
