New technology visualizes the electronic movement of lithium battery -Lithium - Ion Battery Equipment
To develop lithium-ion batteries with high capacity and long life, it is necessary to store as much lithium as possible in the electrode active materials and design materials that can produce a large number of electrons. For this reason, it is very important to master the movement of electrons in the battery, while the previous decomposition technology could not directly observe the movement of electrons. Therefore, it is impossible to quantitatively identify which elements in electrode active substances (manganese (Mn), cobalt (Co), nickel (Ni), oxygen (O), etc.) can release electrons to what extent.(Lithium - Ion Battery Equipment)
The decomposition method developed this time makes it possible to find out the origin of current during charging and discharging for a long time and grasp it quantitatively, which is the first time in the world (Nissan). Therefore, the phenomena occurring inside the battery, especially the movement of active substances contained in the positive electrode material, can be accurately grasped. This achievement was jointly developed by Nissan ARC, Tokyo University, Kyoto University and Osaka Prefecture University.
Earth simulator is also used
The decomposition method developed this time uses both the X-ray absorption spectroscopy method using the L absorption end and the first principle calculation method using the supercomputer Earth Simulator. Although some people used X-ray absorption spectroscopy to decompose lithium-ion batteries in the past, the use of K absorption terminal is the mainstream. The electrons configured in the K shell nearest to the nucleus are bound in the atom, so the electrons do not directly participate in the charge and discharge.
This decomposition method uses the X absorption spectrophotometry at the L absorption end, so that the electron flow participating in the battery reaction can be observed straightly. In addition, by combining with the first principle calculation method using the earth simulator, the electronic movement that can only be inferred indirectly in the past can be obtained with high accuracy.
Nissan ARC uses this decomposition method to decompose lithium excess cathode materials. The results show that: (1) electrons belonging to oxygen are beneficial to charging reaction at high potential; (2) During discharge, electrons belonging to manganese are beneficial to discharge reaction.