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Materials

Graphene’s global race to market

Could low-cost manufacturing techniques finally broaden commercial adoption of the two-dimensional material?

by Alex Scott
April 11, 2016 | A version of this story appeared in Volume 94, Issue 15

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Credit: University of Manchester
Researchers at NGI are developing an array of applications for graphene, including electronic devices and performance coatings.
Photo of China’s president Xi Jinping touring the U.K.’s National Graphene Institute.
Credit: University of Manchester
Researchers at NGI are developing an array of applications for graphene, including electronic devices and performance coatings.

Crowds of flag-waving Chinese students lined the streets of Manchester, England, in October 2015 to cheer the arrival of China’s President Xi Jinping. He was in the provincial city not to visit its famous soccer teams but to see the U.K.’s new National Graphene Institute (NGI), a publicly funded, $90 million hub dedicated to research and commercialization of the carbon material.

Xi sees graphene as a major business opportunity for China. In a sign of the country’s commercial ambitions, on the day of Xi’s visit, China’s largest cell phone producer, Huawei, announced a partnership with NGI to research graphene and other emerging two-dimensional materials.

In brief

Research into graphene ­exploded soon after Andre K. Geim and Konstantin S. Novoselov first isolated the material in 2003 at England’s University of Manchester. Graphene’s extraordinary properties quickly gained interest from the electronics and other industries, even amid questions about feasibility and cost. Now, a new wave of low-cost manufacturing processes is opening the door for its use across a range of applications. Read on to see which companies and countries are likely to be the winners in the race to commercialize graphene.

With a regular hexagonal carbon lattice a mere single-atom layer thick, graphene is the thinnest material on Earth. It is also the strongest material, one of the best thermal conductors, a better electrical conductor than copper, the most impermeable material, and the only material that interacts with light over the entire spectrum. It has a surface area of 2,500 m2 per gram and can be bent and stretched to 120% of its length.

Other materials may have one of those properties. Graphene stands out because it has them all, and more, in one simple crystal.

While academic laboratories are undertaking the lion’s share of research into graphene, hundreds of companies are now looking to sell or commercialize the material. For years graphene has been touted as a “wonder” material. Some experts say it is too expensive to compete with existing products and that its fate is to be relegated to just a few niche applications. An increasing number of market watchers, though, say the low-cost manufacturing processes now emerging could pave the way for wide adoption.

Meanwhile, at the global scale there has been a shift. Graphene was first isolated at the University of Manchester and quickly became the darling of many a research lab in the West. But in recent years, Asian firms and universities—especially those in China—have been filing far more graphene-related patents than their counterparts in Europe and North America. The newcomers hope to be in a prime position to commercialize the material.

With the recently opened NGI, operated by the University of Manchester, the U.K. is seeking to get back in the race. The university hopes the institute, which is available to 250 2-D materials researchers from the university and its 50 partner companies, will be the core of a Graphene City, much like California’s Silicon Valley, says James Baker, the institute’s commercial director. By 2018 the university hopes to open an $85 million building for scaling up projects first developed at NGI.

Because it is still a relatively new material, graphene is so far mostly being added, typically in the form of small stacks of graphene sheets, to existing processes or substituted for certain product ingredients. As an example, in volumes of 1% or less it can be added to an existing polymer to add strength as well as function. Sports equipment maker Head, for example, adds graphene to the stems of some of its tennis rackets to reduce weight and add stiffness.

Graphene is also being used in conductive inks, lubricants, and anticorrosion coatings. It could soon be found in a broader range of products, including lithium-ion batteries and medical sensors, and be modified into membranes for desalinating seawater or separating gases. Large-scale high-tech applications such as bendable phones and screens are still years away, experts say.

Graphene by the numbers

$30 million: Expected worldwide sales of graphene in 2016

>$220 million: Expected worldwide sales of graphene in 2026

6: How many times graphene is as effective at conducting electricity as copper

500: The number of graphene-related patent families filed by Samsung

2003: The year the University of Manchester’s Andre K. Geim and Konstantin S. Novoselov first isolated graphene using sticky tape

7: The number of research papers published daily about graphene

$1.1 billion: The 10-year budget of the European Commission’s Graphene Flagship

120%: The amount graphene can be stretched

47%: The share of graphene patents first filed by organizations in China

$90 million: The cost of building the U.K.’s National Graphene Institute at the University of Manchester

>26,000: The number of graphene-related patents filed worldwide to date

“Every new material, however revolutionary, must go through various stages of commercial development. We are at the very first stage for graphene,” says Andre K. Geim, a professor at the University of Manchester.

It was in 2003 at the University of Manchester that Geim and his colleague Konstantin S. Novoselov first isolated graphene. They were removing flakes from a lump of graphite using sticky tape and noticed some flakes were thinner than others. By repeating the removal of layers with the tape they were able to isolate flakes just one atom thick. The two were recognized for their discovery with the Nobel Prize for Physics in 2010.

Although graphene was first isolated only 13 years ago, sales in 2016 are on track to total $30 million, according to the U.K. market research firm IDTechEx.

And as commercial uses appear, gra­phene-related research continues to rise. Several scientific papers about graphene are now published every day. Many labs are intensively exploring how it could be produced or combined with other materials.

The Intellectual Property Office (IPO), a U.K. government agency, estimates that of the 26,000 graphene-related patent applications filed globally between 2005 and 2014, 47% were first filed in China and 13% in South Korea. To date, 18% of all graphene-related patents were first filed in the U.S. The U.K. is responsible for just 1% of the total.

Of the top 20 organizations to file graphene-related patent applications, IBM is the only one located outside Asia. The top filer is the South Korean electronics giant Samsung, with about 500 families of related patents. Its patent applications are focused on flexible electronics, lithium-ion batteries, transistors, and semiconductors. The firm declined to discuss its graphene technology strategy.

The Korea Advanced Institute of Science & Technology, located in Daejeon, South Korea, has filed 227 graphene-related patents, more than any other university in the world. KAIST’s activities relating to graphene and 2-D materials are driven by a desire to support key Korean industries such as semiconductors, displays, and automobile manufacturing, according to Sung-Yool Choi, director of KAIST’s Graphene Research Center.

KAIST is working on projects relevant to displays and photovoltaics, for which graphene may be used as transparent conducting electrodes, Choi says. The institute is also researching large-area, uniform production of graphene. It has collaborations with more than a dozen companies, including the Korean stalwarts Samsung, LG, and Hyundai Motors.

China rising
More than half of all graphene-related patents are now being filed initially in China.
Note: Unique patents filed with national and regional patent authorities. Source: U.K. Intellectual Property Office

NGI is also working closely with partner companies, including some Asian firms. Allegations published recently in a U.K. newspaper, however, suggest intellectual property originating at NGI could be in danger of being “siphoned off” to China by BGT Materials, a Taiwanese firm that is an NGI partner. NGI and BGT deny the allegation along with the suggestion that researchers in Manchester are boycotting NGI over fears that their work is not secure.

Nevertheless, in the past month the U.K. government’s Science & Technology Committee has begun an inquiry to determine whether graphene intellectual property has been mishandled.

Intensifying
[+]Enlarge
The number of patent applications for graphene-related technology continues to rise.
Note: Total patents filed with national and regional patent authorities.
Source: U.K. Intellectual Property Office
A bar graph showing that patent applications for graphene-related technology continues to rise.
The number of patent applications for graphene-related technology continues to rise.
Note: Total patents filed with national and regional patent authorities.
Source: U.K. Intellectual Property Office

U.K. politicians got involved because graphene is considered a major industrial opportunity. IPO estimates that graphene sales—not including the value the material may add to products—will rise to about $390 million in 2024. Another forecast, from IDTechEx, puts sales at $220 million in 2026, when volumes will be about 3,800 metric tons.

Using graphene in conductive inks and functional coatings is “low-hanging fruit,” according to IDTechEx. Graphene can be added in tiny quantities to carbon inks to enhance conductivity or to anticorrosion coatings to reduce the amount of zinc required.

Adding graphene to electrodes for lithium-ion and lithium-sulfur batteries is another near-term opportunity, says Khasha Ghaffarzadeh, head of consulting for IDTechEx.

By 2026, he forecasts, about $100 million worth of graphene will be sold for batteries and other energy storage applications. Nearly $60 million will be sold into the composite plastics market, where graphene can boost the performance of low-cost plastics, IDTechEx estimates.

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Credit: Trinity College Dublin
Thomas Swan is manufacturing sheets of graphene, shown here, using an exfoliation process developed at Trinity College Dublin.
Sheets of graphene are shown in an image taken from an electron microscope.
Credit: Trinity College Dublin
Thomas Swan is manufacturing sheets of graphene, shown here, using an exfoliation process developed at Trinity College Dublin.

Chemical maker Huntsman Corp. intends to be a key player in graphene-plastics composites, says David A. Hatrick, European technology director for Huntsman Advanced Materials. Last year Huntsman formed a collaboration with U.K.-based Haydale Composite Solutions to develop graphene-enhanced composites.

Haydale uses a plasma process to add custom functionality to graphene nanoplatelets, which are small stacks of graphene between one and six layers thick. Tests by U.S.-based Aerospace Corp. show that the tensile strength of epoxy resins can be increased 100% when functionalized graphene is added, according to Haydale.

By adding graphene, Huntsman can ­improve the resin’s thermal conductivity, enabling it to cool much faster during molding. Thermal conductivity “is one of the biggest challenges faced by the composite molding sector,” Hatrick says. “I would be dispirited if we didn’t have customers testing graphene products within the next 12 months.”

Although Haydale is set to tread new ground with its plasma process, Europe as a whole appears to be trailing the U.S. and Asia when it comes to graphene commercialization. The region is attempting to catch up, though, through Graphene Flagship, the European Commission’s largest-ever focused R&D initiative, with a budget of $1.1 billion over 10 years.

The initiative features a consortium of 142 academic and industrial research groups in 23 countries across Europe. In 2014, Flagship’s first full year of operation, members published more than 300 peer-reviewed papers and filed several patent applications.

BASF, a Flagship partner, is collaborating with several organizations worldwide including the National University of Singapore to develop graphene organic light-emitting diodes. But BASF is keeping a lid on any expectations it may have for graphene. “A few of the topics appear to fit with BASF, but at present it is still too early to judge on the long-term impact of graphene on our product portfolio,” the firm says.

One academic organization to benefit from funding and networking opportunities under Graphene Flagship is Ireland’s Advanced Materials & BioEngineering Research center, a partnership among Trinity College Dublin, University College Cork, and the Royal College of Surgeons in ­Ireland.

Researchers led by Trinity physics professor Jonathan N. Coleman have developed a low-cost process to make graphene nanoplatelets by exfoliating layers of the material from graphite. The college has licensed the technology to Samsung and the U.K. specialty chemical firm Thomas Swan.

Thomas Swan’s sales of graphene nanoplatelets made with Coleman’s process have been so successful that the firm recently increased its manufacturing capacity to 15 metric tons per year. The firm plans to raise capacity by a few more tons in the coming months.

“It is a very good material in applications requiring electrical conductivity or controlled electrical resistance,” says Andy Goodwin, commercial director for Thomas Swan’s advanced materials. The firm is optimistic that demand will continue to rise. “We are working with several key customers,” Goodwin says.

In what Thomas Swan claims is a global first, it has begun selling boron nitride, another 2-D material. “Key characteristics of boron nitride are that it has excellent thermal conductivity, but it does not conduct electricity. It is also white, so it can readily be added to plastics,” Goodwin says.

There are dozens of 2-D materials that could be generated using Coleman’s exfoliation process, Goodwin says. Thomas Swan plans to begin producing another of them, molybdenum disulfide, later this year. Potentially, layers of different 2-D materials could be combined to create a multifunctional material.

“The biggest challenge is working out where these materials fit and where they can add value,” Goodwin says.

Although Thomas Swan has big plans for 2-D materials, its goals are modest compared with some other companies. Spanish firm Graphenano has boldly claimed that by the end of this year it will roll out graphene-polymer batteries with triple the energy density of lithium-ion batteries.

Graphenano is predicting a battery energy density of 1,000 Wh/kg, compared with about 180 Wh/kg for standard lithium-ion batteries. Such a battery might triple the range of a Tesla Model S electric car to more than 1,000 km, the firm says.

Professor of nanotechnology Andrea C. Ferrari, director of Cambridge University’s Graphene Centre, wouldn’t comment on the specific claims of Graphenano, but he says batteries and supercapacitors are areas in which graphene could have a large impact.

Whereas Ferrari expects it will take 10–20 years for graphene to move into regular commercial use, start-ups developing graphene-containing electronic products are confident that they will be on the market within the next few years.

One example is a low-cost touch interface for wearable electronic devices, according to Mike Banach, technical director for FlexEnable, a U.K. developer of flexible organic transistors. “Looking further forward, graphene could be a key enabler for making devices like this stretchable,” he says.

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Princeton University spin-off Vorbeck Materials started marketing graphene and graphene inks about five years ago and is now selling graphene-enhanced radio frequency identification tags. Graphene enables the tags to be used at high temperatures and pressures without being compromised, says Vorbeck President John Lettow.

This year Vorbeck rolled out graphene-based antennae for cell phones with improved range and data transfer rates, and an antenna for military radios that is superior to the long, whippy antenna of old, Lettow says. The firm is also on track to be one of the first producers of commercial lithium-sulfur batteries featuring graphene.

“There are significant numbers of graphene applications that are getting to the market now,” Lettow says. “The next two to three years will attract a significantly greater number of players.”

Lettow is bullish about the prospects for U.S. firms. “A lot of broad patents were filed in the U.S. very early in the graphene game, and it’s very difficult to turn the clock back on patents,” he says. Asian organizations may be filing the most patents now, but many of these will be for specific applications. This could give some U.S. firms the upper hand, he says.

As it is, Vorbeck has two full-time patent professionals, formerly from DuPont and IBM, who file about four patents per month. “The goal is still to build on those early areas” of intellectual property, Lettow says.

The variety of processing options for graphene as well as its relatively affordable price means that commercialization will be much more rapid than for carbon nanotubes, Lettow argues. According to IDTechEx, in 10 years graphene could cost as little as $58 per kg.

“I would be dispirited if we didn’t have customers testing graphene products within the next 12 months.”

David A. Hatrick, European technology director, Hunstman Advanced Materials

Trinity’s Coleman also takes the line that the opportunities for graphene will trump those for carbon nanotubes. “The advantage graphene has is that there is scope for getting the levels of perfection you would equate with incredibly expensive, good quality nanotubes potentially for the very low price you would associate with poor quality nanotubes,” Coleman says.

Another reason why graphene has a better chance than nanotubes is a sea change in the past decade in the way academia supports new technology, Coleman says, such as Europe’s Graphene Flagship. “Nanotubes never had that,” he says.

Among U.S. universities, California Institute of Technology has been making a series of graphene-manufacturing breakthroughs. There, physics professor Nai-Chang Yeh has developed a low-cost chemical vapor deposition (CVD) process for making high-quality single-layer graphene sheets for electronic applications.

Photo of China’s president Xi Jinping touring the U.K.’s National Graphene Institute.
Credit: University of Manchester
China’s President Xi Jinping recently toured the U.K.’s National Graphene Institute with dignitaries including Andre K. Geim (third from left).

About a year ago Yeh’s lab came out with a process using a deposition chamber that could make 1 cm2 of high-quality graphene. “And yet now we are going to build a much larger system allowing for sheets of about 1 m2,” she says.

“That’s a real-world size,” Yeh says. Producing large sheets at low cost “is a game changer” that will enable use of graphene in electronics, she says. Yeh is working with a major semiconductor firm, which she declines to name, to further develop the process.

In another commercially focused project, Yeh’s team is developing a version of its process for growing low-cost graphene nanoribbons. The interest here is that the edges of such graphene ribbons can store electricity. Potentially, lots of nanoribbons collectively weighing hundreds of grams could be incorporated in a capacitor to form a supercapacitor.

“It could really affect the world of energy storage,” Yeh says. High-quality carbon nanotubes could have similar performance characteristics but are prohibitively expensive, she adds.

The near-term use of graphene in high-tech applications such as electronics will be a relative rarity, however, warns Peter Budd, a chemistry professor at the University of Manchester. He pours cold water on the idea that graphene will be all things to all products because ultimately, he says, it is too expensive.

“The hard commercial reality is that the material used is often not the one with the best properties, but the one with adequate properties combined with low cost and ease of production. In all application areas there is competition, and we will see if graphene wins.”

Budd is irritated by media hype surrounding graphene, especially claims that a single layer of the material could act as a membrane for desalinating seawater.

“In the real world, a graphene sheet can’t be dangled into water,” he says. “It would have to be part of a more complex engineering structure. Additionally, the current polyamide-based membranes that are widely used in reverse-osmosis desalination systems are pretty efficient already.”

As new, more efficient graphene manufacturing processes emerge, though, the material is on course to become cheaper. The price of graphene is already falling, with some suppliers quoting prices of less than $100 per kg, according to IDTechEx. Graphenea, a start-up based in San Sebastián, Spain, and a partner of Graphene Flagship, predicts bulk graphene prices may drop below those of silicon, enabling graphene to compete in the electronics market.

Asian countries such as South Korea and China, which already hold strong positions in the electronics industry, intend to be at the heart of the action for graphene. “We wish to be a part of the history,” KAIST’s Choi says.

Geim, who first isolated graphene, is convinced that graphene and other 2-D materials are already on the path to widespread commercialization. “People will continue to investigate them and find uses; 2-D materials are ‘doomed’ to permeate many if not all industries,” he says. “These changes are happening right now.”  


How to make graphene

Chemical vapor deposition and exfoliation have emerged as the two primary routes for commercial graphene production.

In the chemical vapor deposition (CVD) process, methane and hydrogen are heated in a chamber, depositing graphene sheets on a substrate often made of an exotic form of copper. In 2014, Samsung and South Korea’s Sungkyunkwan University were the first to report use of CVD to generate a large, impurity-free sheet of graphene capable of maintaining its electrical properties.

The downside to CVD is that it can be expensive. Researchers in academia and industry are seeking ways of cutting costs.

In November 2015, researchers from the University of Glasgow and Bilkent University jointly published details of a lower-cost CVD technology they used to grow graphene on commercially available copper foil. The process still results in high-quality films with good structural, electrical, and optical properties, the researchers say. They were able to transfer the graphene onto a photoresist material as well as onto polyvinyl chloride.

Another reason CVD is so expensive is that it can require temperatures as high as 1,000 °C. In a 2015 study, Caltech researchers realized they could grow graphene on copper at ambient temperature if they first treated the copper to make it clean and free of copper oxide.

In another step forward for CVD, a consortium of European universities and companies with $8 million in funding recently developed a continuous roll-to-roll process for depositing a graphene layer on a copper sheet measuring about 30 cm wide and multiple meters long. Production costs are now affordable for a number of industries, says project coordinator John Robertson of the University of Cambridge.

Exfoliation is much cheaper than CVD but less precise. Here, graphene is isolated by mechanical means. An exfoliation process developed in 2014 by Jonathan N. Coleman, a professor at Trinity College Dublin, involves the shear mixing of water, detergents, and solvents with graphite powder at ambient temperature and atmospheric pressure.

In the process, graphite powder fragments into nanosheets. Solvents prevent the graphene from aggregating. The exfoliation process typically generates small flakes, or “platelets,” of graphene between one and six layers thick, rather than a single layer. A subsequent step can be applied to raise the monolayer content to 75%.

Coleman has used the process to generate other 2-D materials such as boron nitride and molybdenum disulfide.

Some market analysts say the less precise and smaller graphene flakes generated by Coleman’s method will be suitable for 90% of graphene’s applications, such as those in coatings and plastic composites. The large, blemish-free sheets required for making displays and high-end electronics will likely require CVD. “There are two different markets,” Coleman says. “We’re not competing.”

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