Why UK firm Superdielectrics is hailing an energy storage breakthrough

According to a 2023 report from the Royal Society, the UK will require up to 100 Terawatt-hours (TWh) of storage by 2050, equivalent to more than 5,000 Dinorwig pumped hydroelectric dams. The majority of that figure will be long duration storage, expected to take the form of hydrogen and advanced compressed air energy storage (ACAES), technologies still in their relative infancy. In the shorter term, there is also huge demand emerging for rapid-response battery storage.

To decarbonise Britain’s grid – something the Conservatives are targeting by 2035 and Labour by 2030 - hundreds of gigawatt hours of this type of storage are needed. But this battery boom is not without consequences. There is already widespread concern over the environmental impact the pursuit of battery materials is having, a pursuit only set to intensify as electrification ramps up. The cost – to both planet and people – weighs increasingly heavy and is grist to the mill for net zero sceptics.

Superdielectrics, a UK firm based in Cambridge, claims to have found a low-cost and sustainable solution to the battery storage conundrum. Developed in partnership with researchers at the University of Bristol, the aqueous polymer-based technology acts as a hybrid between a supercapacitor and a chemical battery, offering advantages of both. According to Professor Marcus Newborough, Superdielectrics director of R&D, the company’s tech can already match the energy density of lead acid batteries, but charges 10 times faster.

“We think the ability to charge rapidly - and discharge rapidly if needed - is a key characteristic relative to battery technologies,” Prof Newborough told assembled guests at a March press event. 

“Constructionally, everything we have, our IP, is based on crosslinked hydrophilic polymer materials. Crosslinked means the polymer chains are interconnected in a sort of 3D matrix, which gives the polymer strength and self-supporting characteristics.

“The membrane is ion-selective. So we can do electrochemistry, as well as electrostatic storage. It’s very, very low cost as a polymer compared with the industry…roughly 50 per cent of our materials are made of water. It’s a very benign substance… there’s no lithium, no cadmium, no cobalt.”

The Superdielectrics team was reluctant to share the exact composition of its polymer technology, which the company has already protected around the world via 10 different patent families. However, Professor David Fermin, who steered Bristol University’s recent work with Superdielectrics, described how testing has shown it can already compete with prevalent storage technologies.

“We found that the devices that were developed by the company actually have energy densities that are comparable to some of the existing technologies - like lead acid batteries or nickel cadmium batteries - but has 100 times more power, so they can deliver the energy 100 times quicker,” said Prof Fermin head of Bristol University’s Electrochemistry and Solar Team.

“They have potentially very low environmental toxicity, non-critical elements, and the capacity to be recycled, to a large extent.

Held at the Institution of Engineering and Technology (IET) in London, the press event featured a demonstration of Superdielectrics’ new Faraday 1 storage device. Following an introductory presentation, Prof Newborough walked to an adjacent room where a prototype Faraday 1 system was powering a cluster of bright lights.

Faraday 1 has completed over 1 million hours of testing and the company believes the technology is now ready for home storage as well as lighter mobility applications. As energy density improves, heavier EV applications including aerospace and automotive should be possible. Superdielectrics claims to have already increased its cell energy density by 900 per cent over the past two years. With continued improvement, the team believes it can potentially compete with lithium-ion batteries on power density, but without the reliance on rare earth metals and their associated costs.

“Lithium-ion batteries, we all know how much they cost, and we’re all using them,” said Jim Heathcote, Superdielectrics CEO. “But there is a big problem coming. And that is unless we can recycle them with low energy and low cost, we’re going to be left with a toxic waste problem. So we’re only doing half of the equation on lithium-ion batteries at the moment.”

For now, the wider lithium-ion market, including the automotive industry, is beyond the technology’s limits. Faraday 1’s rapid charging capabilities but comparatively low energy density means the company is targeting lighter mobility modes such as electric bikes and forklifts, as well as the growing home storage market.

“The amount of energy mankind uses in the year is the equivalent to the amount of energy that arrives at the Earth in one hour,” said Heathcote. “If every roof inside the M25 had solar panels and an affordable energy storage technology, the UK could be self-sufficient in electricity.

“Just in England and Wales, there are approximately 20 million houses. If each one had one kilowatt hour of energy storage, that would add 20 gigawatts of energy storage capacity to the UK grid.”

According to Heathcote, the company is planning to lease Superdielectrics storage systems to households across the UK. He claimed consumers could benefit from the storage technology regardless of whether it was paired with domestic solar generation.

“I would imagine that we would be leasing these one kilowatt units for roughly £300 a year,” he said. “So on 20 million homes, that gives you just in England and Wales a £6 billion potential market. And that’s what we’re developing towards for our first markets.”

The company also sees a market for larger scale applications such as grid balancing, as well as the lead-acid battery segment, said to have an annual value north of $40 billion. Elsewhere, Heathcote believes the technology could play an important role for developing nations near the equator, helping them tap into abundant solar resources available in the region. Enabling developing countries to grow their economies and improve quality of life without expanding fossil fuels is a major challenge. As the price of solar energy continues to tumble, cheap, clean energy storage will be a crucial piece of the puzzle. 

“Some of the locations in the world with the highest solar energy, have some of the poorest people in the world,” said the Superdielectrics CEO. “An affordable and sustainable energy system could improve the quality of life for everyone everywhere on the planet.

“We’ve got a new energy storage technology that’s compatible with fluctuations. It charges very quickly. It’s safe, 50 per cent water, very unlikely to catch fire. It’s low cost. And it’s recyclable. And it has the potential to exceed existing battery technologies.”