University of Waterloo researchers have developed a new generation of battery technology, can produce a stable small volume, long battery life, in addition to the convenience of small wearable device installation, can also be used for electric vehicles. Chen Zhongwei (sound) is a University of Waterloo professor of chemical engineers, who is responsible for the entire project, a group of researchers who led the research team to do, the performance is said to be greatly improved battery life, far more than the lithium-ion batteries on the market. The research has been published in the journal Nature communications.
researchers how to do to reduce the size of the battery case, but also to ensure long life? The answer is that they use silicon as a negative electrode material and solve the material drawbacks.
is well known that graphite has been used for a long time as a negative electrode material in lithium ion batteries. But with the battery technology, the material itself has gradually become the bottleneck of the development of battery performance, because the graphite energy storage has reached the limit, research institutions began to search new anode materials, which is an attempt to use silicon as anode. In theory, the specific capacity of silicon material is much larger than that of graphite material. The value of specific capacity is directly reflected by the unit weight of the battery power can be released. At present, the negative electrode active material widely used in commercial lithium ion battery is graphite, which is about 360mAh/g. University of Waterloo, the choice of the use of the theory of silicon materials than the capacity of 4200mAh/g, is more than 10 times the graphite. Chen Zhongwei said that this means that a single charge of electric vehicles can be up to 500 kilometers, and smaller than the current electric car battery is lighter, can be weight loss for the body. However, the attempt to use silicon as a negative electrode material is not in a minority, so far, it has not been widely used because of some technical difficulties. We know that the battery cathode materials and the safety of the battery also has a lot of correlation, and the short board of the silicon anode material is that the security is poor, the volume change of charge and discharge is great. Each charge is placed, the volume shrinkage of the silicon material is up to 300%. Each increase in volume and reduce the crack will form, reduce the performance of the battery performance, resulting in short circuit, and ultimately lead to the battery to stop working.
University of Waterloo researchers in the use of silicon materials research and development process to focus on solving the problem is also the problem. Professor Chen's team cooperation and GM's global R & D center research and development of heat treatment technology of silicon electrode, the charging process of the volume expansion is reduced to a minimum, so as to improve the process performance of battery and lithium ion battery charge and discharge cycle. This heat treatment technology has created a unique structure of the silicon anode, with the battery energy capacity of the upgrade, you can increase the charging and discharging cycle to 2000 times. Silicon anode battery is a research topic of Professor Chen, he said the battery technology has the possibility of commercial production, the research team hopes to see the new battery to enter the market before next year. He led the team to study the major projects including the development of a new generation of unique nano materials clean, sustainable energy technology. In addition, they also pay attention to including metal air batteries, lithium sulfur batteries and various types of liquid flow battery.