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　　There is a new breakthrough in graphene lithium batteries! Graphene has new surprises!

　　Not long ago, a research team from Tsinghua University announced the invention of a smart graphene artificial larynx, which uses the advantages of porous graphene material to create an integrated acoustic device that is both transceiver and wearable and is expected to solve the problem of deaf-mute people in the future. Speaking problem.

　　Internationally, researchers from institutions such as the University of Cambridge in the United Kingdom reported that they have found a new way to awaken the superconductivity of graphene. The awakened graphene can be used to build supercomputers and so on.

　　Graphene is the hottest new material at the moment. In special fields, people use rare elements to describe materials with perfect performance that are as light as air and as hard as steel. Previously, titanium alloy was considered the closest to the ideal choice of this quality, while graphene, a rising star, was considered to be one step closer to the rare element that humans dream of.

　　What is graphene

　　The thinnest, lightest and strongest material in the world, which is 100 times stronger than the strongest steel.

　　Like diamond, graphite is a form of carbon. The difference is that due to different atomic structures, diamond is the hardest thing on earth, while graphite is one of the softest minerals, often made into graphite rods and pencil leads. Graphene is peeled off from graphite material and consists of only a layer of carbon atoms on a flat surface.

　　It can be said that one of the characteristics of graphene is its thinness. It is currently the thinnest material in the world. It is only as thick as one atom, about 0.3 nanometers, which is one hundred thousandth of the thickness of an A4 paper and 50 times the thickness of a human hair. One in ten thousand. At the same time, it can conduct electricity. The speed of electrons in graphene reaches 1000 kilometers per second, which is 1/300 of the speed of light. Thin, strong, electrically conductive, thermally conductive... these properties of graphene give people a lot of room for imagination.

　　Dr. Kong Yuechan, deputy director of the Key Laboratory of Microwave Millimeter Wave Monolithic Integration and Modular Circuits of the 55th Institute of Electronic Technology of China, said that the hardness of graphene is very strong, 100 times stronger than the strongest steel today; the electron speed of graphene is also very high. High, 10 times that of silicon, which is very suitable for the development of next-generation ultra-high frequency electronic devices. In addition, graphene is also a master at conducting heat, 10 times better than the most thermally conductive metal, silver.

　　The properties of graphene are also very interesting. For example, when a drop of water rolls on the surface of graphene, graphene can keenly detect the subtle movement and generate a continuous electric current. This property gives scientists a new way to harvest electrical energy from the flow of water.

　　Graphene can sense single electrons, and the movement of charged particles on the surface of graphene can cause the rapid movement of electrons within graphene to achieve sensing and power generation processes. Lin Shisheng, associate professor at the School of Information and Electronic Engineering at Zhejiang University, said that this characteristic of graphene can have many applications in energy and electronic sensing. For example, umbrellas coated with graphene can be used to generate electricity on rainy days, or they can be made into Sensitive sensing devices, etc.

　　It is these comprehensive properties that have attracted unprecedented attention to graphene. Some people have even begun to predict that the emergence of graphene will lead to an industrial revolution triggered by material advancement.

　　How to get graphene

　　For the first time in the world, a single layer of graphene was obtained, which was glued together with transparent glue.

　　The first time people obtained graphene, they used a simple and crude method.

　　Graphene itself occurs in nature. Graphene is a thin sheet of carbon atoms that form a hexagonal ring that is connected to form a honeycomb plane. It is stacked layer by layer to form graphite. Graphite 1 mm thick contains approximately 3 million layers of graphene. When a pencil lightly scratches the paper, the traces left behind may be several to dozens of layers of graphene. Previously, this two-dimensional structure of carbon has always existed in people's conjectures, but it was difficult to peel off the single-layer structure. The key problem is how to layer graphite into extremely thin sheets.

　　Many people also had this experience when they were students. When they wrote a typo on paper, they would use transparent tape to remove the typo. But no one thought that it was such a simple method that allowed people to discover the mysterious graphene.

　　To make graphene, simply put, it means to make graphite thin, not by cutting or grinding, but by sticking. In 2004, Heim and Novoselov of the University of Manchester in the United Kingdom used transparent glue to repeatedly paste and tear a graphite sheet. The thickness of the graphite sheet gradually decreased, and finally formed graphene with a thickness of only 0.335 nanometers, that is, Graphene is only one atom thick. This is the first time in the world that a single layer of graphene has been obtained, and the two scientists won the 2010 Nobel Prize in Physics.

　　Dr. Wu Yun, a senior engineer at the Key Laboratory of Microwave and Millimeter Wave Monolithic Integration and Module Circuits of the 55th Institute of Electronic Technology of China, gave a demonstration to reporters. He stuck a small piece of graphite on top of the tape and then peeled it overlappingly. After sticking for half an hour, the tape was covered with gray graphite, and then the graphite was transferred to a clean silicon wafer using tape.

　　Wu Yun said that what he sees at this time is not graphene, because graphene is not only very thin, but also has a transmittance of more than 97%, almost completely transparent, and cannot be seen by the naked eye. To find it, you have to through dedicated technical means. But this is already a multi-layered graphite sheet. Only by positioning and determining the number of layers through technical means can we finally find the single-layer graphene produced.

　　Experts say this is just the way graphene was originally produced. The mechanical peeling method, which evolved from the tape pasting method, is just a method for preparing graphene in the laboratory. Currently, with technological advancement, high-quality graphene can be produced in greater quantities.

　　What will graphene bring?

　　Using graphene material, mobile phone screens can be easily bent or even folded

　　The emergence of graphene is expected to bring surprises to our lives. Mobile phones can be charged in seconds, mobile phone screens can be easily bent or even folded, and cars can use graphene electrostatic conductive tires to avoid deflagration due to frictional electrification... From special aerospace, electronic information to energy conservation and environmental protection, using the characteristics of graphene, many fields are very Big changes may occur.

　　Replacing silicon with graphene can improve the performance of electronic chips. Scientific researchers are currently introducing the production and application of graphene into the semiconductor industry. The technological revolution triggered by graphene is likely to start with our common small chips.

　　The basic material of electronic chips is silicon. However, as components on chips become increasingly dense, the distance between two components on the most high-end chips is less than 10 nanometers, almost reaching the limit of silicon material. What should I do if I want to continue improving performance? Researchers are beginning to try to partially replace silicon with graphene.

　　Devices made of graphene can theoretically reach ten times or even hundreds of times the frequency of silicon, and can be used in special applications to greatly improve the resolution of special applications. And it has a wide range of applications in communications and imaging. Kong Yuechan said that the current R&D and production equipment for graphene is the same as that of ordinary semiconductor equipment production equipment. Existing technology development can be based on mature equipment and processes, laying the foundation for subsequent engineering development.

　　Researchers are also working on another big thing. They attached graphene to a gold foil that was only 50 nanometers thick, and then used a new method to transfer the graphene intact to a soft plastic sheet.

　　Kong Yuechan said that graphene can be transferred to any substrate that researchers want through a flexible method, such as a plastic substrate dedicated to electronic devices. It is flexible and suitable for the preparation process of transistors. Through special graphene transfer technology, the gold foil with graphene is attached to the plastic sheet, and based on this, electronic devices with certain functions are prepared on this plastic sheet. Crucially, such electronic devices can be easily bent. In the future, whether it is a foldable display screen or a wearable device that can be implanted in the human body, it is possible to rely on such graphene devices.

　　Another promising application area for graphene is the storage of electrical energy. At the Tianjin Power Source Research Institute, researchers here are conducting research on state-of-the-art capacitors. Capacitors, like batteries, can be used to store electrical energy. Its advantage is that it charges quickly, can be fully charged in a few minutes, and can be reused tens of thousands of times. However, it does not store as much power as a battery, and it cannot store enough electrical energy to be used in daily life.

　　This is the slurry made of modified graphene that we have prepared. Next, we will apply the slurry to the aluminum foil through a coating machine to become the positive electrode used in our graphene capacitor. Dr. Ding Fei, executive deputy director of the Key Laboratory of Special Science and Technology of Chemical and Physical Power Source Technology of the 18th Institute of China Electronics Technology, said that capacitor materials have a crucial impact on the performance of capacitors. By further modifying graphene materials, scientific researchers are making the storage capacity of capacitors step by step closer to batteries. At the same time, its ultra-fast charging speed can bring more convenience to people's lives. The modified graphene capacitor we are making can be fully charged in a few minutes, and its energy density is expected to be close to the energy density of existing lithium batteries after a period of time.

　　Energy density refers to the amount of energy stored in a certain space or mass of material. The higher the energy density, the stronger the electricity storage capacity of the material. According to Ding Fei, the energy density of the modified graphene capacitor samples they have developed has reached more than three times that of traditional capacitors. Although it is still in the laboratory research stage, the powerful capabilities of graphene materials allow the R&D team to see broad prospects for the application of modified graphene capacitors.

　　In the future, when charging facilities become more and more complete, electric vehicles using graphene batteries may be fully charged in two to three minutes.

　　Gao Tao, director of the 55th Institute of China Electronics Technology and director of the Key Laboratory of Microwave and Millimeter Wave Monolithic Integration and Modular Circuits, believes that even under laboratory conditions, the magical properties of graphene have not been fully released. At the same time, there are still many challenges at the technical level, and there is still a long way to go for true large-scale application. However, by strengthening the combination of demand and research, important breakthroughs have been made in the preparation of graphene materials and device development. Graphene, a new generation of strategic emerging materials, will greatly change people's lives.

　　Technology Zone 220V AC to 12V DC reference design The current status of domestic lithium battery ternary material patent technology layout What is the echelon utilization of automotive power batteries? It will become a hot issue for a long time. New energy vehicle design cannot be ignored Cells and battery materials 2020 China’s automotive power battery pack shipments and forecasts in 2020

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