On March 8, Toray Industries, Inc., headquartered in Tokyo, Japan, announced that the company has successfully developed an ultra-thin graphene dispersion solution with excellent fluidity, electrical conductivity, and thermal conductivity. Applications in fields such as batteries, wiring materials, and paint are very profitable. Toray will continue to promote the research and development of this breakthrough and accelerate its commercialization process.
Graphene is a sheet-like two-dimensional carbon material with nano-scale size and ultra-thinness. This advanced functional material is easy to arrange evenly, which contributes to its excellent electrical conductivity and barrier properties. As a sheet material, a single carbon atom (layer) is combined in a honeycomb structure. Multilayer sheets are also called graphene. The graphene currently developed by Toray is a sheet with about 10 layers.
So far, Toray has developed a technology that uses cheap graphite materials to make very thin, high-quality graphene. However, the problem is that thinner graphene is more likely to aggregate. Conversely, a higher concentration makes graphene more like clay, which hinders fluidity. The application and mixing of graphene in clay is difficult, so it is necessary to dilute it and use it in a low-concentration solution, but this again masks the inherent advantages of graphene.
Based on the above background, Toray has developed a dispersion technology that controls viscosity by adding a unique polymer material, and this polymer material can inhibit the aggregation caused by the interaction between graphene, its excellent As a result, the fluidity of the high-concentration ultra-thin graphene dispersion is increased. This system has excellent fluidity even at high concentrations.
Proprietary dispersant to improve the fluidity of graphene dispersions
The solution is easy to handle and handle without dilution, and it is easier to show its excellent conductivity and other advantages. High dispersibility and easy mixing make it easy to mix the solution with other materials. A good application of this new solution is as a conductive material for lithium-ion batteries. It can be easily mixed with cathode materials, and graphene is inserted between the cathodes to improve conductivity.
By using the above method, the capacity loss of the lithium ion battery due to the degradation of the conductive path during the repeated charging and discharging process can be reduced, thereby further extending the battery life. In the past material systems, high-performance batteries for electric vehicles usually use carbon nanotubes as the conductive agent. After Toray’s test and comparison, the results show that the battery life based on this new dispersion system is longer than the traditional use of carbon nanotubes as the conductive agent. The battery life is 50% longer.
It is also worth noting that the graphene dispersion system can also be used in electronic circuit systems. For example, the graphene is laminated to form a dense film by coating and drying the solution. This film can be used in printable electronic circuits. High durability and conductivity, will not rust like metal.
Other potential application areas of the graphene dispersion system may include mixing the solution with anti-corrosion coatings to prevent water and oxygen from penetrating and causing rust, thereby improving durability.
For a long time, Toray`s mission has been to provide innovative technologies and advanced materials to provide real solutions to the world’s challenges in balancing development and sustainability. In the future, Toray will continue to devote itself to the development of revolutionary materials that will change society, conform to its promised innovative ideas, technologies and products, and provide new value.