Since its discovery in 2004, graphene has promised to become the world’s next wonder material. For the energy sector, it could unlock new possibilities for power generation, storage and infrastructure
Stories of supposedly groundbreaking technologies seem to be around every corner. It is rare, however, for these innovations to actually change the world. One material that succeeded in disproving its sceptics was plastic – dating back to the mid-19th century, synthetic polymers have had a profound impact on the planet. As their price tumbled in the 1950s and 60s, plastics were used in the mass production of items that never would have been possible without the material’s pliability, strength and lightweight quality. Plastic products, from disposable syringes to water bottles to contact lenses, have helped boost living standards around the world.
Graphene boasts an impressive collection of superlatives: not only is it the world’s thinnest material, but it is also the strongest
However, plastic is now falling out of favour due to its contribution to environmental pollution and its role in encouraging a throw-away culture. But there is another wonder material promising disruption on a global scale: graphene. According to the University of Manchester, which was the site of graphene’s discovery, “combining all of graphene’s amazing properties could create an impact of the scale last seen with the Industrial Revolution”.
Graphene is made up of a single microscopic layer of carbon atoms laid out in a honeycomb-like lattice. Although it can be found in an object as ordinary as a pencil, graphene is a completely extraordinary material. In 2004, two researchers from the University of Manchester – Andre Geim and Kostya Novoselov – became the first to isolate graphene by sticking adhesive tape to a piece of graphite. When they pulled the tape away, they were able to separate a single layer of carbon, opening the door to a new class of two-dimensional materials. The pair won the 2010 Nobel Prize in Physics for their “groundbreaking experiments” with graphene.
Graphene boasts an impressive collection of superlatives: not only is it the world’s thinnest material, but it is also the strongest. It is tougher than diamonds, more conductive than copper and incredibly flexible. Graphene is also completely transparent while still being extremely dense.
Around the world, entrepreneurs and businesses are taking note of the remarkable material. Between 2010 and 2017, the number of patent filings related to graphene grew at an average rate of nearly 61 percent per year to reach 13,371, according to market research firm ReportLinker.
Graphene’s appeal is nearly universal. Its flexibility and transparency could one day contribute to a phone that could be rolled up like a newspaper, while its incredible strength allows it to take a hit twice as well as Kevlar, the fabric currently used in bulletproof vests. As a replacement for health-tracking wearables like Fitbits, graphene could be tattooed directly onto the skin. In the future, aeroplanes, cars and countless other machines could be manufactured out of lightweight, superstrong graphene. Already the material has been injected into tennis rackets to enhance their durability.
Value of the graphene market
In the energy sector, there are a number of ways graphene could enhance power generation, storage and infrastructure. As Craig Dawson, a graphene applications manager at the University of Manchester’s Graphene Engineering Innovation Centre, told The New Economy: “Because graphene has the ability to serve several purposes, often at the same time, we could see its use [becoming] ubiquitous across the sector.”
Rapidly growing interest in the material has seen the value of the graphene market soar from $85m in 2017 to nearly $200m in 2018, ReportLinker said. Predictions vary about how quickly the market will continue to grow. While market research firm IDTechEx expects the industry to be worth $300m by 2027, ReportLinker said it could reach as much as $1bn by just 2023, with China leading the way in research and development.
Khasha Ghaffarzadeh, Research Director at IDTechEx, wrote in 2018 that China has developed a huge monopoly on technology development, dominating sectors from solar photovoltaics to 3D printing. It’s no surprise, then, that the country quickly became the centre of graphene innovation. According to Ghaffarzadeh, the largest suppliers of advanced materials like graphene are Chinese, and nearly 70 percent of the total nominal production capacity is located in the country.
Globally, the amount of electricity generated by renewable energy sources is on the rise. In 2017, nearly 24 percent of electricity produced around the world came from renewables. By 2023, the International Energy Agency (IEA) expects that figure to rise to almost 30 percent. Led by solar, wind and hydropower, renewables are set to meet more than 70 percent of global electricity-generation growth, the IEA said.
One big snag in the development of the renewables industry has been the fact that green sources of energy are produced intermittently – when the sun is shining or the wind blowing, for example. To ensure excess energy can be held back and deployed once again when the clouds come out, energy storage will be a vital element of the renewable energy mix.
Dawson and his colleagues at the University of Manchester see graphene as a good candidate for the creation of next-generation batteries, thanks to the material’s mechanical and chemical robustness alongside its impressive conductivity. “Graphene’s impermeability could be useful within devices such as fuel cells and grid-scale redox batteries where protons can hop across the graphene-enhanced membranes,” Dawson explained.
Graphene meets all the qualities of an ideal energy storage device, according to Rob Dryfe, a professor at the University of Manchester. Speaking about graphene in a video for the university, Dryfe said: “[You] want a high-surface, high-volume, light, stable, conducting material, and the advantage of graphene is that it basically ticks all of those boxes.”
Most energy storage devices today use lithium-ion batteries, which can be made up of various formulations of lithium, cobalt, aluminium, nickel and manganese. While lithium-ion batteries are prized for their ability to hold a charge, they are not efficient when it comes to shifting energy in and out of batteries quickly. For this reason, graphene supercapacitors would be ideal for electric vehicles – especially high-end supercars. As well as enabling cars to reach a high speed in seconds, supercapacitors could allow electric vehicles – as well as other electronics like phones and laptops – to be fully charged almost instantly.
Supercapacitors and batteries each have their benefits and downfalls. “Where high power is required, a supercapacitor could be advantageous, and where a large charge capacity is required, a battery is probably more suitable,” Dawson explained. Graphene researchers are also looking into the development of graphene supercapacitor hybrid batteries, which Dawson said would offer the best of both worlds.
Some players within the graphene supply chain, including students and partners of the University of Manchester and corporations like Samsung, have seen “tangible results” of such graphene-modified batteries and supercapacitors, Dawson said. “We could, therefore, expect to see these enter the market in the near future.”
For now, these devices need further research to become fully optimised for use in the energy sector. Nunzio Motta, a professor of science and engineering at the Queensland University of Technology, told The New Economy this is another area where China is ahead of the curve. Some Chinese companies are already producing commercial graphene batteries and supercapacitors, he said, which are being used to power electric buses.
Graphene’s utility extends far beyond batteries and supercapacitors, but because it was discovered less than two decades ago, many of its possibilities are still unknown. Researchers are working on experiments today that just five or 10 years ago wouldn’t have seemed possible.
For instance, Dawson said graphene’s dual transparency and conductivity means the material could be used to improve the efficiency of solar cells. This could help end the industry’s reliance on rare materials such as indium tin oxide, an expensive material that can be used as a thin film. “[Graphene] is also impermeable to almost everything, protecting energy infrastructure from the elements,” he added.
In 2012, researchers made carbon-based solar cells using graphene, which they said would be more easily produced and recycled than existing solar cell designs. The prototypes were expensive to make, however, and the scientists said more research was needed in order to optimise efficiencies.
Other projects are ongoing, including a joint venture between UK-based energy technology developer Verditek and graphene specialist Paragraf. The two teamed up in 2017 to create “a new generation of highly robust, ultra-lightweight” graphene-based solar panels that could “potentially revolutionise the photovoltaic market”. Researchers at three Australian universities, meanwhile, joined together to develop a light-absorbing, ultra-thin film that they said has “great potential” for use in solar thermal energy harvesting. Upon presenting their findings in March, the scientists said the graphene film offers a “new concept” for solar energy, opening new research areas, including in the direct conversion of heat to electricity and the desalination of water.
Motta told The New Economy that he does not see graphene as a suitable material for solar cells, but that it could be useful in concentrating solar power plants, which use mirrors to focus sunlight into a central tower where water is boiled to generate superheated steam. “Mirrors covered with graphene could have some application because graphene could conduct the heat very well,” Motta said. The possible applications of graphene elsewhere in the energy industry are far-reaching, including reinforcing materials used in wind turbine blades and lacing concrete used to build other energy structures with graphene.
Graphene is not only revolutionary because of what it can do – it has also changed scientists’ understanding of similar resources. Take superconductors, for example: these materials are able to conduct electricity with no resistance, meaning energy in a superconductor could flow continuously without ever degrading.
The problem with most superconductors is that they only work at temperatures near absolute zero, or about –273.15 degrees Celsius, where there is no motion or heat. Because it is impractical to run superconductors with the expensive cooling materials needed to make them work, scientists have spent decades searching for a material that could be used as a superconductor at room temperature.
Graphene, while not a high-temperature superconductor in itself, has brought scientists a step closer to solving this puzzle. Two papers published in the science journal Nature in 2018 proved that graphene could work as a superconductor if two layers were sandwiched together at the so-called ‘magic angle’. The researchers found that graphene works in a similar way to other ‘unconventional’ superconductors called cuprates, which can conduct electricity at up to 133 degrees Kelvin above absolute zero, or around –140 degrees Celsius.
While scientists have struggled to understand the workings of cuprates, the graphene system was relatively well understood. “The stunning implication is that cuprate superconductivity was something simple all along. It was just hard to calculate properly,” Robert Laughlin, a physicist and Nobel laureate at Stanford University, said at the time of the announcement. While Laughlin said it was not yet clear whether the behaviour of cuprates would match that of graphene, he said enough behaviours were present to “give cause for celebration”.
In the coming years, China will continue to dominate the graphene market, according to Ghaffarzadeh, who wrote that China has “the technology, the investment, the resolve and the value chain, including all the major target markets”. Elsewhere in the world, there remains a disconnect between the technical research into graphene and the businesses that can create practical, innovative products. Dawson said the umbrella group Graphene@Manchester, which includes the university’s Graphene Engineering Innovation Centre and its National Graphene Institute, aims to bridge the “innovation gap” between academia and the commercial world by forging collaborative partnerships between researchers and corporate entities.
Going forward, experts expect a critical juncture to take place in the global development of the graphene industry. Ghaffarzadeh has suggested a “major turning point” for graphene would occur in 2020 or 2021, while Graphene@Manchester CEO James Baker told China Daily that the tipping point could come as soon as the end of the year.
However, in a report published in 2016, consultancy firm Deloitte said the research and prototyping phase for graphene would likely extend for another decade. The report noted that throughout history, the materials that make the biggest impact tend to take decades of development before achieving mainstream adoption. Graphene products created in 2016 were just offering a glimpse of the material’s full potential, the Deloitte report said: “Some of the future technologies and benefits of graphene, which could embody the ‘graphene era’ and change our world, only currently exist within the realms of our imagination.”
Although it is almost certain that graphene will not solve every problem researchers claim it will, its discovery in 2004 has already opened the door to countless new areas of research and product design. For the energy sector, graphene’s arrival has led to groundbreaking discoveries and innovative new ideas – but this could just be the beginning. As Motta said: “We’re probably just scratching the surface regarding what graphene can do for the future energy sector.”