The Germans figured out how to increase the capacity of lithium-ion batteries by a third

Researchers from the German Institute of Technology Karlsruhe (KIT) published published an article in Nature Communications that explained the mechanism of cathode degradation in high-energy lithium-ion batteries. The research was carried out as part of the development of batteries with increased capacity and efficiency. Without an accurate understanding of cathode degradation processes, it is impossible to successfully increase the capacity of batteries with the highest efficiency, which is necessary for the development of electric vehicles. Scientists are confident that the knowledge gained will allow the capacity of lithium-ion batteries to be increased by 30%.

High performance batteries for automotive and other applications require a different cathode structure. In modern lithium-ion batteries, the cathode is a multilayer structure of oxides with varying ratios of nickel, manganese and cobalt. High-energy batteries require manganese-enriched cathodes with excess lithium, which increases the ability to store energy per unit volume/mass of cathode material. But such materials were subject to rapid degradation.

During normal operation, when the cathode becomes enriched or loses lithium ions, the high-energy cathode material is destroyed. After a certain time, the layered oxide turns into a crystalline structure with extremely unfavorable electrochemical properties. This occurs already in the early stages of battery operation, which leads to a rapid decrease in the average charge and discharge values.

In a series of experiments, German scientists found that degradation does not occur directly, but indirectly through the formation of difficult-to-determine reactions with the formation of solid lithium-containing salts. In addition, oxygen appears to play an important role in the reactions. The researchers were also able to draw new conclusions about chemical processes in lithium-ion batteries that may not lead to cathode degradation. Using the results obtained, scientists hope to minimize cathode degradation and eventually develop a new type of battery with increased capacity.

Source: 3dnews.ru