Materials for large-capacity lithium-ion batteries

'This battery has reached the highest capacity of transition metal oxide electrode batteries in history, more than twice that of batteries in mobile phones and tablets currently in use. 'Christopher Wolverton, a professor of materials science at Northwestern University's McCormick School of Engineering, who is in charge of the research, said,'Such a high battery capacity is a big step forward for the goal of using lithium-ion batteries in electric vehicles. 'The results of the study were published on Science Advances on May 14. Lithium-ion batteries work by moving lithium ions back and forth between the cathode and anode. The cathode is composed of a compound containing lithium ions, a transition metal, and oxygen. When lithium ions move from the anode to the cathode, or from the cathode back to the anode, the transition metal (usually cobalt) effectively stores and releases electrical energy. The cathode capacity is limited by the electrons that can participate in the reaction in the transition metal. A French research group first reported a large-capacity lithium manganese oxide compound in 2016. By replacing the traditional cobalt with cheaper manganese, the team developed a cheaper electrode with twice the capacity of traditional batteries. But this research ran into challenges: The battery’s performance dropped significantly after only two rounds of charging, preventing the battery’s commercialization. And they did not fully understand the chemical nature of the battery's large capacity and capacity decline. After studying the detailed schematic diagram of the atomic cathode structure, Wolverton's team discovered the reason behind the large capacity of the material: it promotes oxygen to participate in the reaction. In addition to the use of transition metals, by using oxygen to store and release electrical energy, the battery has the ability to store and use more lithium. Next, the Northwestern University team turned its attention to stabilizing the battery to prevent its storage capacity from rapidly declining. 'According to the knowledge of charge and discharge, we use high-throughput calculations to traverse the periodic table of elements, looking for elements suitable for integration into the electrodes to improve battery performance. 'One of the first authors of the paper and a former doctoral student in Wolverton's laboratory, ZhenpengYao said. This calculation method identified two elements: chromium and vanadium. The team predicts that the use of any of them mixed with lithium manganese oxide will produce compounds that maintain the high capacity of the cathode. Next, Wolverton and his collaborators will test these theoretical compounds in the laboratory. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete it.