Graphene is a two-dimensional carbon nanomaterial with a hexagonal honeycomb lattice composed of carbon atoms in accordance with sp⊃2; chemical orbital, with a thickness of one carbon atom.
Graphene first appeared in 2004. In a laboratory at the University of Manchester in the United Kingdom, two scientists successfully separated graphene from graphite by micromechanical exfoliation. 1mm thick graphite contains about 3 million layers of graphene. It shows the difficulty of peeling off.
Because of its unique electrical properties, mechanical properties, optical properties, thermal properties and high specific surface area, graphene has received great attention in the fields of chemistry, physics, materials, energy and environment in recent years. It has broad prospects and is recognized as 21 practical " "Future material" and "revolutionary material". It is expected that by around 2024, graphene devices are expected to replace complementary metal oxide semiconductor (CMOS) devices and find applications in research fields such as nanoelectronic devices, photoelectrochemical cells, and ultralight aircraft materials.
Graphene market
my country’s graphene industry is showing a trend of rapid development. According to statistics, the market size of my country’s graphene industry has reached 10 billion yuan in 2018, an average annual increase of more than 100% from the 600 million yuan in 2015. It is expected that by the end of 2020, the global The domestic graphene industry market size is 9.5 billion U.S. dollars and 20 billion U.S. dollars respectively. The Chinese graphene market accounts for about 30% of the global graphene market, and it has a trend of increasing year by year. Six industrial application fields, mainly new energy, coatings, health, energy saving and environmental protection, new chemical materials, and electronic information, have been initially formed. Among them, the market scale in the field of new energy accounts for more than 60%.
Graphene applications
Super capacitor: Solve the bottleneck of long charging time and short battery life
Supercapacitor refers to a new type of energy storage device between traditional capacitors and rechargeable batteries. It not only has the characteristics of fast charging and discharging of capacitors, but also has the energy storage characteristics of batteries. It is an electrochemical with high energy density. Capacitors are hundreds to thousands times higher in capacity than traditional electrolytic capacitors. Compared with batteries and traditional physical capacitors, the characteristics of supercapacitors are mainly embodied in high power density, long cycle life, wide operating temperature limit, maintenance-free, and environmental protection. Graphene has good electrical conductivity, high density and specific surface area, and is an ideal material for supercapacitors.
Anticorrosive coating: significant advantages in thermal stability and antibacterial properties
Anti-corrosion coatings refer to anti-corrosion coatings which are composed of primer, middle paint and top coat with anti-corrosion function. According to different coating applications, they can be divided into conventional anti-corrosion coatings and heavy anti-corrosion coatings. my country's anti-corrosion coatings market is huge, and the scale is still growing year by year.
Compared with other anti-corrosion coatings, graphene anti-corrosion coatings have more obvious advantages in terms of electrical conductivity, thermal stability, mechanical properties, and antibacterial properties. Due to its good electrical conductivity and sheet-like overlap barrier properties, graphene can shield oxygen and corrosive media, reduce the permeability of the anti-corrosion coating, and improve the anti-corrosion performance of the coating. China's anti-corrosion coatings are developing rapidly. In 2019, my country's total output of anti-corrosion coatings was 5.35 million tons, an increase of 18.4% year-on-year, accounting for 22.2% of total coating output.
Lithium battery conductive agent: demand support & cost reduction industry high growth rate
The primary function of the conductive agent for lithium batteries is to improve the electronic conductivity. The conductive agent functions to collect micro currents between active materials and between active materials and current collectors to reduce the contact resistance of the electrodes, increase the electron migration rate in lithium batteries, and reduce battery polarization. In addition, the conductive agent can also improve the workability of the pole piece and promote the infiltration of the pole piece by the electrolyte, thereby increasing the service life of the lithium battery. Commonly used conductive agents for lithium batteries can be divided into two categories: the first category is traditional conductive agents (such as carbon black, conductive graphite, carbon fiber, etc.), and the second category is new conductive agents (such as carbon nanotubes, graphene and their mixed conductive agents). Slurry, etc.).
Flexible display: wearable devices are the main driving force in the market
Graphene film has good electrical conductivity, high flexibility, strong light transmission and other reasons, and can be widely used in the field of flexible display in the future. At present, the most widely used flexible display screen on the market is ITO film (ceramic material indium tin oxide). The production process of this material is becoming mature and the price is lower. However, after bending, it no longer has electrical conductivity, which cannot meet the needs of flexible display screens for future mobile devices and wearable devices. Graphene film is considered to be superior to ITO film due to its good electrical conductivity, flexibility, and light transmittance. It is more suitable for the future development trend of flexible displays, and is considered to be a perfect substitute for ITO film.
Sensor: Graphene is chemically sensitive and has broad prospects in medical and other fields
Graphene is a good material for making chemical sensors. This process is mainly accomplished by exciting the adsorption properties of the plasma surface by the surface infrared beam of graphene, and the sensitivity of the graphene chemical detector is very high. The unique two-dimensional structure of graphene makes it very sensitive to the surrounding environment. Graphene is an ideal material for electrochemical biosensors, and sensors made of graphene have good sensitivity in medicine.