Is graphene the answer to transforming energy transfer in the green economy?

Supercapacitors are fast becoming the power-boosting energy storage device of choice for the world’s growing fleet of electric vehicles, industrial machines and electronic consumer goods. Graphene’s unique properties could deliver the enhanced energy transfer capability required for increasing electrification, decarbonisation and greening economies.

First Graphene’s (FGR) continued development of its PureGRAPH? range of graphene-based products and research into how they can be used to enhance supercapacitors – which store and provide bursts of electrical charge – may be transformational and could revolutionise cell-based energy transfer across multiple applications.

Typically used in conjunction with traditional batteries to give surges of energy or smooth out intermittent power supply, supercapacitors are a hybrid between the traditional electrolyte-based battery and the capacitor. Generally speaking, they are attractive due to their high power density, fast charge and discharge rate, long-term stability and safety features.

In a supercapacitor, charged ions are stored on the surface of the electrodes, ready for immediate use. However, a key difference to traditional capacitors is that an electrolyte is used to transfer and balance the charge between electrodes.

Graphene enters the mix as a value-adding ingredient

Graphene has been considered as an alternative to state-of-the-art carbon-based materials used to store charge at the electrodes of supercapacitors. The reason for this is the impressive surface area offered by graphene. The greater the surface area, the higher the charge-storage capacity.

The concept of graphene being added to supercapacitors was first described by Meryl D Stoller in her paper Graphene-Based Ultracapacitors, which was published by the American Chemical Society in 2008 and since received almost 7,000 citations.

Stoller et. al. recognised that graphene functioned as a suitable replacement for carbon material, offered high electrical conductivity and demonstrated the “exciting potential for high performance, electrical energy storage devices based on this new class of carbon material”.

Fast forward more than a decade and the development of supercapacitors – both with and without graphene – has the potential to revolutionise energy storage.

Namely this is through the fast and efficient discharge and recharge of electrical energy, making them an ideal option for a wide range of applications, from consumer electronics to electric vehicles (EVs).

The latter is of particular interest. The advent of EVs has catalysed demand for batteries – and by extension supercapacitors – as the automotive industry moves towards a greener vehicle fleet.

Supercapacitors provide a range of benefits to EVs, including extra power output, smoothing of acceleration and regenerative braking.

By 2030 EVs are projected to represent more than 60% of vehicles sold globally, meaning there is a growing appetite for improving characteristics mentioned above, as well as range and recharge speed.

First Graphene research looks at cost-effective alternatives

Cognisant of the exponential demand for novel energy storage solutions – shared by heavy industry to electrify their vehicle and machine fleets, household appliance manufacturers and those creating devices connected to the Internet of Things – First Graphene is increasing investment in the use of graphene in energy generation and storage technology.

A recent collaborative project with Professor Robert Dryfe and Dr Andinet Ejigu from The University of Manchester’s School of Chemistry demonstrated that graphene can reduce reliance on rare (and expensive) battery metal oxides and adds significant longevity to supercapacitor cycles.

Materials were tested for up to 10,000 cycles without a degradation in performance, a signal that the addition of graphene can help them reach high cycle targets required.

From a cost reduction perspective, testing has shown that rare metal oxide content in supercapacitors can potentially be reduced by a factor of four.

This technology has also been applied to research into the use of FGR’s graphene material as an electrocatalyst for the production of green hydrogen.

Ongoing investment to optimise technology

First Graphene’s research has continued off the back of supercapacitor development research carried out in 2022 by Professor Mark Copley, from Warwick University’s science, technology and collaborator arm Warwick Manufacturing Group (WMG).

Further studies have been carried out on cycle testing and metal ratio optimisation with Professor Robert Dryfe.

At a higher level, the focus is on continuing particle size optimisation of active graphene materials to provide the smooth coatings required inside batteries and supercapacitors for cell stability, performance reliability and easy manufacture, potentially at a lower price point.

FGR is continuing its investment towards energy generation and storage solutions.

A significant portion of investment will look to developing high performance supercapacitor materials, leveraging expertise in graphene technology to create more efficient and effective energy storage solutions.

The bigger picture of FGR’s investment into this segment – and specifically supercapacitors – is the emerging global market, which is shaping up to be a significant growth opportunity.

According to Markets and Markets, the global supercapacitor sector was expected to grow from US$819 million in 2020 to US$2.1 billion by 2025, representing a CAGR of 20.7% during the forecast period.

Global Market Insights takes it a step further, identifying the total global opportunity for supercapacitors will reach US$5 billion by 2027.

Much of this growth is slated to stem from increased demand for use in EV production in the Asia-Pacific region – South Korea, Japan, Thailand, China and India – which already holds a clear lead when it comes to supercapacitor market revenue.

The opportunity isn’t isolated to EVs

Growth of the supercapacitor market is being driven by several factors, including increasing demand for energy-efficient solutions in heavy industry and electronics, the growing adoption of renewable energy sources, and an increasing focus on reducing carbon emissions.

For example in wind turbines, supercapacitors are used to smooth out intermittency and fluctuation of wind energy making their feed into grid systems more efficient. They can also be used to provide short bursts of power controlling blade pitch in milliseconds to enhance yield and avoid damage in high winds.

From a heavy and industrial machinery perspective, cranes, port-based loading equipment, haul trucks, diggers and other equipment are already benefitting from supercapacitors. In military applications, laser and projectile launching devices draw vast bursts of energy from power stored in supercapacitor banks to activate.

At the smaller end, supercapacitors are used in an array of consumer electronic goods – mobile devices, radio transceivers, solenoids, wireless modems, laptops and camera flashes.

So while development of supercapacitors and the role graphene plays in optimizing their performance continues, a clear projected growth in demand means companies focused on green economy outcomes – like First Graphene – are in the driving seat when it comes to seizing opportunities associated with decarbonisation.