“The future of graphene is now”

By Emma Hughes
Published: Monday, 28 April 2014

Commercial applications on the horizon; Prices could come down as volumes increase

Several speakers at the Graphene Live! 2014 conference held in Berlin, Germany, at the beginning of April, acknowledged the fact that the nano-carbon material has a long way to go before it is considered fully commercial

They highlighted that while a lot has been spent in researching this material, and developments are coming in thick and fast, graphene is yet to find its “killer application”.

While no breakthrough use has been pinpointed, graphene has been utilised in a wide range of end-markets, some of which have seen it used as a replacement material while others are new technology applications made possible through graphene’s unique characteristics.

Two of the most talked about applications for graphene at the conference were energy storage and supercapacitors.

Dr Paolo Bondavali, head of nanomaterials at France’s Thales Group, explained that graphene exhibits several characteristics that make it a viable supercapacitor material.

Such characteristics include very high rates of charge and discharge, high life cycle (>100,000), good reversibility, low toxicity of material used, high cycle efficiency, low internal resistance - making for a higher power output - and extremely low heating levels.

Several of these properties also mean graphene is being considered as an alternative raw material component in lithium-ion

(Li-ion) batteries, which traditionally use graphite (graphene’s precursor material) in anodes and cathodes.

This was discussed by Dr Rune Wendelbo, chief technology officer (CTO) of Norway’s Graphene Batteries.

Wendelbo explained that “carbon is a necessary evil in batteries” but added that graphene could be used as a graphite substitute as a conductive scaffold in the cathode, as an anode material, as an additive to other anode materials (such as silicon) or as a current collector coating.

However, while graphene holds large potential in this area - especially considering the predicted increase in demand for Li-ion batteries with the rise of electric vehicles (EVs) - there are some issues associated with its use, Wendelbo said.

One of these issues is that, while graphene is extremely conductive, its inherent structure makes it more difficult for Li-ions to travel when compared with the use of carbon black.

For this reason, companies like Graphene Batteries have been researching graphene morphology, which helps to improve ionic flow within a cell. Mixing graphene with carbon black has also helped to improve overall performance, Wendelbo outlined.

“Graphene type and formulation methods are the keys to successfully utilising the potential of graphene in batteries and supercapacitors,” he said.

Graphene has also found a use in solar energy applications, as discussed by CrayoNano AS at this year’s Graphene Live! event.

The company’s founder and CTO, Dr Helge Weman, told delegates that his team could have a graphene/nanowire solar cell prototype ready in just six months’ time.

The hybrid device, which utilises graphene as a semiconductor substrate in place of other materials such as indium phosphate, copper or silicon, has been able to achieve cell efficiencies of around 68% in a laboratory environment.

“This is more than double the efficiency of traditional solar cells (...) We believe this technology is really scalable,” Weman explained.

“Our technology will be used to produce and deliver epi-wafers used in many kinds of semiconductor applications [in the future],” he added.

Specialist uses

Other graphene applications discussed during the event included printed electronics, graphene electronics, touch screens and inks. Its use in the medical industry was touched upon by Grafoid Inc.’s president and CTO, Dr Gordon Chiu.

Grafoid, which launched MesoGraf, a trademarked graphene intermediate product, in 2013, has been forming strategic partnerships to ramp up the commercialisation of the material.

At the beginning of April, Grafoid announced a new partnership with Altamat that will see the construction of a graphene-3D printing facility in Canada.

In September last year, the company formed a joint venture company, Calevia Inc., with ProScan RX Pharma Inc. to develop new graphene-based nanotechnology for the precise targeting and thermal eradication of solid cancer tumours.

“Calevia sets a clear example to the world [of] how graphene technologies serve humanity,” Grafoid CEO, Gary Economo, said on announcing the partnership. “As a business, the MesoGraf-based therapy we aim to bring to market leaves us well positioned with the potential to re-define the treatment for tumorous cancers,” he added.

Expense barrier

While graphene exhibits many unique and valuable properties, its brilliance comes at a cost.

As with any new material, graphene has not yet benefited from economics of scale, meaning that its raw cost, the method by which it is produced and its quality are all interlinked.

According to the University of Manchester, the best quality of graphene currently available from its start-up commercial entity costs £1,000/mm2 ($1,656*). This graphene is produced individually using a micro-mechanical cleavage method.

Other options available include graphene grown through chemical vapour deposition (CVD), which can be around £10/cm2, but “it is inherently of significantly poorer quality, especially for high performance electronics applications” the University of Manchester states.

Graphene produced via ultrasonic exfoliation of graphite ore can be obtained from companies for around the £500/mg mark.

Dr Siva Bohm, principal scientist at Tata Steel, outlined the cost of graphene when talking about the development of graphene steel coatings at Graphene Live! 2014, saying that the raw material cost as well as application costs are a prominent consideration in Tata Steel’s research and development in this space.

However, speaking on the opportunities for graphene in supercapacitors and battery technology, Jesus de La Fuente, CEO of Spain-based Graphenea, said the cost of this ‘wonder material’ could soon be coming down as economies of scale are achieved.

“We can bring down the cost of graphene with volumes, as the manufacturing costs are fixed,” de La Fuente explained.

“Graphene oxide prices are also declining sharply due to production efficiency and economies of scale,” de La Fuente added.

*Conversion made April 2014

What is graphene?

Graphene is a layer of carbon one-atom thick, which can be derived from either natural or synthetic graphite, and is said to be the strongest and thinnest material known to exist.

First discovered in 2004 by physicists at the University of Manchester, UK, the US National Science Foundation estimates that the global market for graphene products will exceed $1 trillion within the next 15 years.

Two of graphene’s major markets involve energy storage - namely, batteries and supercapacitors.

Companies like Samsung Electronics in South Korea have been attempting to speed up the commercialisation of graphene using a breakthrough synthesis method. Samsung has managed to create a larger-than-normal area of graphene, allowing more to be processed than with other conventional methods.

Many governments have also invested in graphene research, including the UK, EU, US and China, with figures showing that thousands of patents for products using the technology have already been filed.

In January 2013, China led the way with 2,204 graphene-related patents, with the US in second place with 1,754 patents.

Graphene-coated steel could prevent corrosion

partnership with UK research body, the Engineering and Physical Sciences Research Council (EPSRC).

Together, the parties will work to develop innovative applications including graphene-coated steels and next-generation sensors that can operate in extreme environments.

Tata Steel produces 1.3m tpa organic coated steel, a product that comes with a 30-year guarantee, meaning anti-corrosion R&D is a large part of the company’s work.

Other key research areas under the partnership will include waste recycling processes and the development of new sensor equipment, whose ability to operate in very high temperatures or extreme chemical environments could lead to greater understanding of metallurgical and chemical properties and processes.

“Our customers want us constantly to develop new and more sophisticated products that will help them overcome their challenges, now and in the future. We also need to develop new manufacturing processes to support product development,” Debashish Bhattacharjee, group director for R&D at Tata Steel, said.

“Our partnership with EPSRC will broaden and enhance our research capabilities, helping to speed up the achievement of these objectives,” he added.