Graphene is an allotrope of carbon. That is to say it is a different form, much like diamonds and graphite. In the form of graphene, carbon is structured in a single two-dimensional layer of hexagonal lattice of. Currently, of graphene’s known properties, the following characteristics are best in world:
Its electron mobility at room temperature is over 15 000 cm2/V•s. Meaning, its conductivity is as high as 108 S/m and the corresponding resistivity is roughly 10-8 Ω•m, better than silver, copper, and even carbon nanotubes or silicon crystals.
Its thermal conductivity is as high as 5 300 W/m•K, much improved over silver or diamond.
Its unique optical properties produce an unexpectedly high opacity for an atomic monolayer in vacuum, absorbing 2.3% of red light, and light transmittance as high as 97.7%. Graphene also has far-infrared heating characteristics.
It is 200 times stronger than the strongest steel alloy.
Due to its excellent electrical conductivity, graphene is widely used for conductive inks, and is used for the purpose of printing conductive dots, lines and areas. It can also be used as an electrode conductive agent and has strong advantages and development prospects. In recent years, graphene inks have made gratifying achievements in the research and development of mobile phones, toys, thin film switches, and IC integrated circuits.
Currently, industrialization and promotion are needed. In the coming decades, the largest downstream conductive ink market will be presented in solar photovoltaic conversion panels and various display device panels. In the future, more graphene conductive ink applications will also grow significantly, including a variety of electronic components electrodes, RFID and electronic paper.
Graphene conductive ink filling also has two main advantages. Firstly, compatibility, whether it is metal foil or plastic film, even on paper and other substrates graphene inks will make these products easier to print on. The second is cost-effectiveness. Graphene inks have greater cost advantages than existing nanometal conductive inks.
Graphene anti-corrosion coating is mainly used in machinery, petroleum, electric power, shipbuilding and other industries. At present, the global consumption of anti-corrosive coatings is close to 4 million tons. Detailed, the demand for anticorrosive coatings is mainly concentrated in the fields of shipbuilding, petro storage and delivery, bridges, containers, etc.
After the graphene is added into the coating, the graphene can form a stable conductive mesh, which effectively inhibits the oxidation reaction on the material. At the same time, the graphene coating can form a physical barrier layer between the metal sheet and the active medium. And the coating plays a very good protective role, thus increasing the life time of the material.
Graphene anti-corrosion coating also improves the utilization of zinc powder in anti-corrosion materials. From the actual effect, adding about 5% of graphene powder can reduce the use of 50% zinc powder and reduce the cost of anti-corrosion materials.
Heat Dissipation Material
The heat dissipation of electronic devices and optical communication devices is a major factor affecting their performance. Improper heat treatment can result in equipment inefficiencies, high temperatures, and even explosions. Samsung Galaxy Note 7 is an example.
The heat dissipation of mobile phones, computers, microcircuits and other devices is mainly solved by various heat sinks. At present, the electronic products of radiators on the market are mainly graphite heat sinks. However, graphene heat sinks have far better thermal conductivity and foldability than graphite sheets, heat-dissipating materials such as heat-conducting fibers, heat-conducting plastics, etc., and the technical difficulty is relatively small, the technology is relatively mature, and there is an opportunity to quickly enter the market.
In the future the field of thin, portable and foldable digital devices such as smartphones will be required in large scale, and the graphene thermal film will have great advantages.
Composite Structural Materials
Since graphene is currently the most intense material in the world, it is or will be widely used in composite structural materials. At present, Italian has built the first graphene F1 race car in the world. It has been not only increased strength (increased safety), but also reduced the weight by 2/3.
Graphene is mainly doped or used as an additive in the composite structural materials. The markets that can be expected are the structural materials of the aircraft, the blades of aircraft engines, the anti-collision materials of automobile trains, the protective armor of tanks and warships, and various bullet-proof devices.
In particular, graphene body armor is not only 100 times more intense than traditional body armor, but also 1/3 or even lighter than conventional body armor.
Graphene is more diversified in various battery applications. It can be used as a conductive agent to improve the conductivity of the battery, improve battery performance and cycle life. It can also be used as doping material or additive material of positive and negative electrodes to improve the specific capacity and charging performance of the battery.
At present, the more mature application is to add graphene to a ternary positive electrode material such as iron phosphate cobalt and coating it with a graphene paste as a conductive agent. The test results show that compared with lithium batteries without graphene, graphene-based lithium batteries have a 30% increase in specific capacity, a 95% reduction in charging time, a doubling in cycle life, a four-fold increase in service life. The amount of heat generated is reduced by 70%.
Graphene-based lithium-ion batteries are mainly used in portable electronic devices such as mobile phones, notebook computers, video cameras, etc. and are actively expanding into new energy automotive fields such as electric vehicles, and have long-term development prospects.
Graphene is not only promising in the development of lithium-ion batteries, but also has bright prospects in new batteries such as fuel cells, flow batteries, air batteries, and lithium-sulfur batteries, and it is even useful in the development of clean energy solar cells.
Graphene has high electrical conductivity, large specific surface area, and stable chemical structure. This makes graphene very suitable as electrode material for supercapacitors. At present, graphene supercapacitors have been successfully developed. In some cases, graphene supercapacitors will replace lithium batteries.
Graphene conductivity is very sensitive to pressure. Therefore, there are good prospects for pressure sensors, radio frequency identification technology, and so on. At the same time, due to its high thermal conductivity, graphene can also be used in thermal sensors. It can also be used in various biometric sensors such as smart packaging and medical monitors.
Far Infrared Heating
Due to far-infrared heating characteristics of graphene, far infrared heating film of graphene can be made. This kind of film can be applied to the clothes so that the light clothes can keep warm and the warm temperature can be controlled. It is also possible to paste far infrared heating film of graphene on the wall or floor to change the traditional way of human heating.
There are so many applications of graphene that cannot be listed here.