Looking for super batteries graphene subversion tradition

In daily life, insufficient battery capacity often plagues electric cars and smart phone users. The super battery with stable performance and reasonable price is the dream pursued by mankind for many years. At this stage, people's image description of a super battery can be summarized as follows: once charging, the electric car can be driven for 1,000 kilometers, and the smart phone can be played for one week. The charging time can be controlled within a few minutes, and wireless charging is preferable. The market size of this super battery is not less than 1 trillion US dollars. At present, the United States, China, Japan, and South Korea are sprinting super batteries.

Currently used lithium-ion batteries began commercialization in 1991, mainly lithium cobalt oxide, lithium iron phosphate and lithium manganese oxide three types. Lithium cobalt oxide batteries have the highest energy density, but are unstable at high temperatures, and the other two energy densities are not high. The fifth generation of rechargeable batteries - lithium metal batteries was born in 1996, in terms of safety, specific capacity, self-discharge rate and cost performance, are better than lithium-ion batteries. However, there is a big gap between the requirements of super batteries.

Graphene is expected to trigger a new breakthrough in the battery. Graphene, which was born in 2004, is characterized by its good electrical and thermal conductivity: as an electrical conductor, its electrical conductivity is comparable to that of metallic copper; as a thermal conductor, it is the best among existing materials, and it is even more commendable that this When the material is very thin, it still has a very high hardness. Graphene has been listed as an important material by major industrial countries for further development. At present, there are basically three directions for the study of graphene on batteries:

One is to form a new system battery with graphene. That is to say, a battery with a brand-new system made of graphene is subversive in performance and is called “super battery”. The battery made of this kind of material has an energy density of more than 600 wh/kg, which is five times that of current lithium-ion batteries. It takes only 8 minutes for a single charge, and it can travel 1,000 kilometers. The battery weighs only half as much as a lithium-ion battery. Reduce, reduce the use of the battery's own weight; battery life is longer, is 4 times the traditional hydrogenation battery, lithium battery 2 times; its cost will be lower than the current lithium battery 77%. These physical parameters are in line with the requirements of super batteries.

The second is to strengthen the existing battery performance with graphene. Graphene is applied to existing batteries to improve the performance of lithium batteries, solar cells, etc., in an effort to achieve the performance of super batteries. For those companies that have invested heavily in the construction of lithium battery factories, it will be difficult to invest in the development of a new type of battery in the short term. It may be more realistic to use the properties of graphene to enhance the performance of existing lithium batteries. In terms of graphene properties, graphene can be widely used in energy storage products such as lithium-ion batteries, super capacitors, and solar cells as the thinnest, hardest, conductive, and highly flexible nanomaterials. The special structure of graphene determines that it can improve the performance of lithium ions in the battery to obtain high-rate channels, and can help lithium battery technology break through the long-term insurmountable obstacles. At present, cell phone batteries developed using graphene and silicon as raw materials require only 15 minutes for each charge, allowing the mobile phone to operate for a week.

The third is graphene-catalyzed fuel cell performance. The special graphene material was used instead of platinum as a catalyst to produce the hydrogen fuel needed for the fuel cell. A fuel cell is a power generation device that directly converts the chemical energy of a fuel into electrical energy. Compared with other batteries, it has the advantages of high energy conversion efficiency and no environmental pollution. "Proton-conducting film" is the core part of fuel cell technology. There are often fuel leaks on existing proton membranes, thereby reducing battery effectiveness. However, protons can easily "pass through" two-dimensional materials such as graphene, while other materials are difficult to traverse, which can solve the problem of fuel permeation, thereby enhancing the performance of the battery.

The application of graphene technology is still in its infancy. In particular, single-layer graphene materials, which can greatly reduce the volume and weight of the battery, have a low yield and high production costs, and have become an important cause of the difficulty in industrialization of graphene batteries. Therefore, by further innovating, improving technical processes and reducing production costs, it is the key to the development of graphene batteries in the future. At present, China has taken the lead in the development and application of graphene, and has made breakthroughs in a variety of graphene batteries and graphene lithium-sulfur batteries.

Of course, global research and development in the field of batteries is not limited to graphene. Japan is researching and developing the use of magnesium to produce batteries with higher performance and lower cost; Sweden is studying the use of carbon fibers to improve the performance of lithium batteries. However, these new technologies need to be truly applied and even form a huge industry. They also need to be baptized by the market.

In short, the process of finding super batteries is the process of technological innovation and the process of optimizing the industrial structure. The day when the super battery represented by graphene achieves a breakthrough, it will include the electric vehicle, mobile phone, computer and other equipments that rely on electric power to transform the equipment. It will be of subversive significance to many industries and will surely open up new opportunities for human life. a page.