Graphene or Substitute for Lithium-ion Batteries Leads Electric Vehicles to a New Era

Although lithium-ion batteries, which store energy, are inexpensive and durable, electric vehicles simply can't go too far without a generator. Even if modern technology is advanced, it takes at least 20 minutes to charge the battery, so it is difficult for electric cars to compete with gasoline and diesel cars.

The

Many people tried to solve this problem and ended in failure. Lu Wu, from Korea's Gwangju Institute of Science and Technology, recently researched the modern ideal material graphene, hoping to commercialize the experimental results and solve the battery problem. Strictly speaking, Dr. Lu and his colleagues are working on supercapacitors instead of batteries. Supercapacitors are devices that combine electrolytes and common capacitors in similar batteries. Supercapacitors are like normal capacitors. Energy is stored on the surface of the material in the form of static electricity. However, unlike ordinary capacitors, when the supercapacitor is charged, static electricity is attached to the surface of the electrolyte. Because the attachment of static electricity rather than the change of chemical state ions (the working principle of the battery) speeds up the storage process, the supercapacitor charges faster than the battery.

The

Supercapacitors are not a new idea. Graphene is a two-dimensional material that is only one carbon atom thick and is particularly suitable for making batteries. With an area of 2675 square meters per gram of graphene, the entire surface can store static electricity, so graphene can be used to make supercapacitors, with more energy than lithium-ion batteries.

The

Dr. Lu's problem is how to use graphene in supercapacitors and conduct rational industrial production. His solution is to control the explosion of graphite pieces that have been blown up. Graphite is formed by stacking planar layers of carbon atoms arranged in layers in honeycomb layers. Graphite layers have weak interlaminar forces and can easily peel off each other to form a thin graphite sheet. When a graphite sheet is stripped into a single layer, the single layer with a thickness of only one carbon atom is graphene.

The

Lu's preparation process includes two phases. First, a powder called graphite oxide was prepared by exposing powdered graphite to air in a controlled manner. But this is not really an oxide with a fixed chemical formula. Instead, it is a graphite-like substance with oxygen-rich atomic groups between the thin layers of graphite. The graphite oxide is then heated in the vessel to 160 degrees, noting that the pressure in the vessel is one-tenth of the atmospheric pressure. Heating causes the graphite oxide to chemically react, producing carbon dioxide and water vapor. After further processing of excess oxygen, graphite is suitable for the preparation of supercapacitors.

The

Although the graphene has a small size, it works well - it can store the stored energy of a kilogram of lithium-ion batteries and is fully charged in four minutes. To increase the amount of graphene to the needs of a car requires a robust system for quick charging. Currently such systems are not suitable for home use and can be installed on roadside gas stations.

The

This will help us to get rid of the current charging problems encountered by electric vehicles. If the crude oil has the energy storage capacity that can match the lithium ion battery, then the improved version will definitely exceed it. The ongoing practice of supercapacitors remains to be seen, but if it proves that it is battery-like, reliable, and inexpensive, it will be a major breakthrough and change the future of car driving.