How Does Graphene Contribute To The Development Of Battery Technology?
In late November 2015, a communications equipment business high-profile published its latest products. The product uses graphene as a battery material, can greatly shorten the charging time, improve the battery charging capacity. This report in one fell swoop caused everyone's attention, and the community's attention to graphene to a new height.
What is graphene?
From Baidu Encyclopedia, we can know:
1. Graphene (Graphene) is extracted from the graphite material, composed of carbon atoms only one layer of atomic thickness of the two-dimensional crystal.
2. graphene is the thinnest material, but also the most powerful material, breaking strength than the best steel even higher 200 times. At the same time it has a very good flexibility, stretching can reach their size 20%. It is the world's thinnest, the highest strength of the material.
3. Graphene is currently found in the thinnest, the largest strength, the strongest thermal conductivity of a new type of nano-materials, graphene is called "black gold."
In a word, graphene is a nanometer order of magnitude material, with high strength, high elasticity and high conductivity and other properties.
As a nanomaterial, graphene gives the impression that it may become a candidate for the manufacture of space elevator materials. Even in Baidu Encyclopedia, the electrical properties of graphene only part of its performance. If it is not in the third point "by the way" to mention its high conductivity, then only from the definition of gravel and the battery is difficult to find the relationship.
However, nanomaterials are a class of worlds that humans do not have, and the common sense we get from the macroscopic world is not well reproduced in the microscopic world.
If the nano-magnitude of graphene can improve the performance of the battery to help, you need to analyze the principle from the battery.
Second, the relationship between electrode material and battery capacity
We know: from the microscopic point of view of the battery charge and discharge process, in fact, is a cation in the electrode "mosaic" and "off" the process. So, the more holes in the electrode material, the more rapid the process is going. In the macro point of view is the performance of the battery charge and discharge faster.
The microstructure of graphene is a network composed of carbon atoms. Because of the thinness of the limit (only the thickness of one layer of atoms), the movement of the cation is limited. At the same time because of the network structure, made of graphene electrode material also has sufficient holes.
From this point of view, graphene is undoubtedly a very good electrode material.
According to researchers at the Rensselaer Polytechnic Institute in New York, the United States shows that the use of graphene as a battery prototype material, the charge and discharge speed will exceed 10 times the lithium-ion battery.
Third, the status of graphene research
Purdue University (Purdue University) is studying through a new, more simple way to create nano-electrode material technology. The University of research shows that the use of nano-materials in the battery, will increase the battery charge capacity and charge and discharge speed.
At present, South Korea's Samsung Electronics is also engaged in the silicon surface to add graphene-coated silicon-based anode material research. If the study can be successful, lithium-ion battery life will be increased to more than 2 times.
This study summarizes the advantages of long life of silicon-based materials and large charging capacity of graphene materials, focusing on how to process the process of graphene on silicon-based materials.
Samsung's researchers have effectively expanded the surface area of the anode by coating a graphene coating on the surface of the silicon carbide electrode. At the same time with the cathode used in the combination of lithium cobalt oxide, so that the battery charge per unit volume of energy density of the larger oil, its life is also increased to the bus market sales of lithium-ion batteries 1.5-1.8 times.