Graphene is a single layer of graphite; an array of carbon atoms arranged in a hexagonal honeycomb lattice. Graphene is expected to enable energy storage devices with several new features that do not exist in the current technology. Nanotech Energy is working on converting this dream into a reality.
How we make graphene
Given its excellent mechanical and electronic properties, graphene is expected to play a critical role in the progress of printed electronics.
Thin, flexible, low-cost and environmentally friendly – this is just a snapshot of what printed electronics can offer.
The rise of this technology can be ascribed to its potential in providing cost-effective solutions to large-area electronic devices at a fraction of the cost of traditional semiconductor technology.
Supercapacitors are attractive energy storage devices with the ability to recharge in seconds rather than hours like traditional lithium-ion batteries.
Supercapacitors are also maintenance free and can be used for up to a million charge/discharge cycles. Their high power density and excellent low temperature performance have made them the technology of choice for back-up power, cold starting, flash cameras, and regenerative braking. They also play an important role in the progress of hybrid and electric vehicles.
However, the low energy density of current supercapacitors is the main impediment to realizing the full commercial potential of this technology.
This has triggered tremendous research efforts on Nanotech Energy’s part in order to develop new electrode materials that are capable of providing a huge amount of energy in a short period of time.
Earliest graphene patent
Nanotech Energy is backed by researchers who are highly experienced in this field and are at the forefront of this cutting edge technology. With a research experience of over 30 years, our team has developed a wide range of nanoscale materials having the potential to change everything from conductive polymers, carbon electronics to water filtration and superhard materials. Filed in May 2002, our research team at UCLA holds one of the earliest patents on making graphene. View the press release
The (Super) Supercapacitor
Unprecedented electronic and structural properties
What is Reduced Graphene Oxide?
Since the graphene industry is growing very rapidly, it is important to distinguish between different graphene products currently available in the market.
The first pieces of single and few-layer graphene nanosheets were obtained through the exfoliation of bulk graphite using scotch tape. Although this route leads to non-defective pristine graphene, its low yield makes it unpractical for large scale. Mass production of graphene was made possible through chemical exfoliation of graphite. This can be achieved by direct exfoliation of graphite in a liquid, with or without a surfactant or by inserting chemical species between graphite interlayers to weaken the forces holding them together, thus facilitating their exfoliation. While these techniques are widely used for the production of graphene with low defects, the product is usually thick and is often referred to as nanoplatelets. These nanoplatelets are suitable for applications requiring high electrical and thermal conductivity but their low surface area and poor dispersibility in various solvents make their further processing difficult.
Solution-based approaches involve chemical oxidation of graphite to graphite oxide, which can be exfoliated to individual layers of graphene oxide sheets by mild ultrasonication or shear mixing in water. Graphene oxide is electrically insulating but can be converted back to the conductive form by reduction using chemical, thermal, solvothermal or laser techniques. The resulting reduced graphene oxide (often abbreviated as rGO) can be processed from solution, opening up vast opportunities for the use of graphene in many technological applications. The processability of rGO allows its direct incorporation into composites where it can improve mechanical and electrical properties of the host material. More importantly, rGO can achieve high surface areas in excess of 1000 m2/g, much higher than other techniques for exfoliating graphite.
It was discovered that the remaining edge defects on the surface of rGO can be beneficial for rapid electron transfer and higher catalytic activities, making this form of graphene ideal for electrochemical and energy storage applications in batteries and supercapacitors. It also shows promise as an active ingredient in inks and coatings for the growing markets of printed electronics and smart packaging. rGO becomes an obvious solution where the users are looking for large quantities of graphene for industrial applications.