Can Scottish seaweed spark a new generation of batteries?

Materials from Scottish-grown seaweed could help to improve the lifespan and charge time of lithium-ion batteries used for the likes of electric vehicles, with a new first-of-its-kind prototype already being tested by expert researchers.

The team from Marine Biopolymers and the University of Glasgow’s School of Chemistry recently received funding from the Industrial Biotechnology Innovation Centre (IBioIC) to explore the use of tailored alginates – a naturally-occurring material found in brown seaweed – to help develop batteries using silicon as an alternative to the currently used graphite.

Graphite or carbon electrodes are a core component of standard lithium-ion batteries but can only store a limited amount of charge and have a restricted overall life-span.

Silicon has been suggested as a viable alternative material for the battery anode, and it can increase the charging capacity by up to ten times. However, when used on its own, silicon expands and contracts each time the battery is cycled, eventually cracking and becoming damaged. This prototype combines silicon with the seaweed-derived alginate to improve the electrode’s elasticity and ability to store energy.

Electric vehicles

So far, a prototype the size of a typical watch battery has been created and tested by the researchers with very encouraging results. They are now keen to develop a larger scale battery to test the technology at scale, proving that the seaweed alginates can be used to significantly boost charging capacity for a range of industrial and consumer products – such as electric vehicles.

Professor Duncan Gregory, chair in Inorganic Materials at the University of Glasgow’s School of Chemistry, said: “Battery technology is going to play a hugely important role in our transition away from fossil fuels.

“Electric vehicles, renewable energy production, national grids, and other critical elements of a net zero future will depend on having batteries that can store large amounts of energy in the smallest volumes possible and with extended lifetimes.

“As well as this, we need to find more sustainable production methods and ways to use naturally occurring materials as part of battery manufacturing. This project has been in the works for some time now and it is great to see initial positive results, combining the expertise from two key fields.”

2-3 times better

The project represents the first time battery scientists have explored the use of this type of tailored alginate for mass commercial applications and researchers have optimised the design and construction of the battery cell to ensure the best possible performance. Estimates suggest the new design will have a life cycle which is two to three times longer than state of the art graphite electrodes.

Marine Biopolymers (MBL), based in Ayr, is an expert in extracting a range of natural polymers from seaweed for different applications such as food and pharmaceuticals. It is also targeting the growing demand for bio-based materials across industrial and manufacturing sectors, including naturally regenerative seaweed which can be harvested sustainably.

MBL product development manager Kirsty Neilson said: “This an exciting first venture into energy storage and we are hoping to be in a position to take a commercial solution to the market in the next three to five years.

“The new technology could underpin an entirely new supply chain and manufacturing market here in Scotland and we have already had encouraging conversations with potential partners. It would be great to see seaweed species indigenous to Scottish coastal waters being used to power everyday electronics and technology in the future.”

A valuable raw material

Scotland has a long history of harvesting wild seaweeds for various uses including animal feed, agricultural fertilisers, and alginates. A 2022 report by IBioIC and the Scottish Association for Marine Science estimated that the sector could grow to generate revenues of £71.2 million per year by 2040, using a combination of both wild and cultivated seaweed.

Liz Fletcher, director of business engagement at IBioIC, added: “Electric vehicles powered in part by a seaweed-based product sounds like something from science fiction, but research and technology continue to push the boundaries and show us what’s possible.

“Seaweed is a valuable raw material with many potential use cases and by supporting companies like Marine Biopolymers with funding, expertise and access to facilities, we can support the development of exciting new bio-based supply chains in Scotland.”