Professor of Chinese Academy of Sciences developed a method for preparing negative electrode of lithium battery with Reed

Recently, a research team from the Key Laboratory of Energy Conversion Materials of the Chinese Academy of Sciences and Professor Yuyan of the School of Materials of the School of Chemistry and Materials of the University of Science and Technology of China, in cooperation with the German Mapug Institute, invented a three-dimensional Silicon negative electrode material made of reeds for lithium ion batteries. Preparation method, Breaking the technical difficulties that previously only used complex chemical steps to form Silicon provides more possibilities for the development of a new generation of lithium-ion batteries in the future.

The current lithium-ion battery mainly uses graphite and modified graphite as negative materials, but its theoretical capacity of 372 mAN/g is difficult to meet the long mileage demand of electric vehicles. In contrast, silicon-based negative electrode materials with higher theoretical capacity(4200 mAN/g) have become the focus of research in the field of negative electrode materials for the next generation of lithium ion batteries. This time, Professor Yuyan's group innovatively adopted reeds as raw materials for preparation, which not only simplified the process, but also reduced the cost.

The method is mainly based on magnesium thermal reduction and dense three-dimensional porous Silicon oxide(SiO2) is reduced from natural Reed leaves. The Reed leaves act as skeletons, and the by-product magnesium oxide(MgO) produced on them serves as the prototype of the hole.

According to the researchers, compared with some current methods for preparing nanostructured silicon-based negative poles, this reed-based method includes the following advantages:

1, Reed Yewei renewable material;

2, the Silicon produced by the reduction maintains the three-dimensional nanostructure of the crude oil Reed Yezhong, which is very conducive to improving the negative electrode performance(because it can slow down the powder of the negative electrode);

3, the method is simple and easy;

4, do not use expensive Silicon starting materials or reaction reagents

When the negative electrode was prepared by this method, the topological structure of the original silicate in the Reed leaves was magically maintained, and it was not destroyed by a few cents in a series of physical and chemical treatment procedures. In the process of purification of dry Reed leaves, the internal three-dimensional structure will only shrink, and the mesopore network can remain intact, even if the subsequent carbonization process does not change it.

According to Liujun of the research team, magnesium fever also has two advantages. First, it can maintain the structure of the original Silicon in the Reed leaves; Second, corrosion of magnesium oxide additives can further increase the density of the inner hole. These two points are supplemented by carbon layers that are later coated on Silicon Motors, which can greatly improve the negative electrochemical performance of lithium ion batteries, such as the high reversible capacity and the high current density of high discharge and discharge. Finally, Reed, as a natural material, provides the possibility for the future large-scale production of high-performance lithium-ion batteries.

The page contains the contents of the machine translation.