Japan’s Nissan Motor Co and its Nissan Arc subsidiary have developed an analysis method to observe the electron activity in the cathode material of lithium-ion batteries directly during charging and discharging. Nissan Arc has teamed up with Tokyo University, Kyoto University and Osaka Prefecture University in a joint R&D project to develop this new technique.

Using this method, which involves X-ray absorption spectroscopy, Nissan Arc says it will be able to develop high-capacity and high-durability batteries to extend the driving distance of zero-emission electric vehicles. A spokesman said: “Scientists have wanted to understand the origin of electrons during charging and discharging for several years, and this newly developed analysis method finally makes it possible. The exact phenomenon inside a battery cell can be observed — especially the behaviour of active materials of electrodes — allowing further study of better-performing longer-lasting electrode materials.”

Nissan Arc has used the new analysis technique to investigate lithium-rich high-capacity electrode materials, which are thought to be promising agents to increase energy density by up to 150%. The analysis revealed that, at a high potential state, electrons originating from oxygen were active during charging. Meanwhile, electrons originating from manganese were observed to be active during discharging. These findings are viewed as a big step towards the commercial development of lithium-rich electrode materials, which can produce higher-capacity long-lasting batteries.