The team from Marine Biopolymers and The University of Glasgow's School of Chemistry 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 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 lifespan. Silicon has been suggested as a viable alternative for the battery anode, and can increase charging capacity by up to ten times.
Used on its own, silicon expands and contracts each time the battery is cycled, eventually cracking and becoming damaged. The researchers' prototype combines silicon with the seaweed-derived alginate to improve the electrode's elasticity and ability to store energy.
A prototype the size of a typical watch battery has already been created and tested by the researchers, with 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."
The project represents the first time that battery scientists have explored the possible use of this type of tailored alginate for large-scale commercial applications. The researchers have optimised the design and construction of the battery cell to ensure the best possible performance. Early estimates suggest that the new design will have a lifecycle two to three times longer than even state-of-the-art graphite electrodes.
For its part, Marine Biopolymers has deployed its expertise 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.
Image credit: Fredrika Carlsson | Unsplash
Kirsty Neilson, product development manager at Marine Biopolymers, said: "This is 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."
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."
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 £71.2m per year by 2040 using a combination of both wild and cultivated seaweed.
In 2022, a research team involving the University of Bristol, Imperial College and University College London demonstrated the use of nanomaterials made from seaweed to create a strong battery separator, paving the way for greener and more efficient energy storage.
A growing number of projects are tapping into seaweed's potential, from feeding and fueling the world with seaweed, to producing biodegradable health sensors that can be applied to the human body like a second skin; combining seaweed alginate with crab shells to spin into sustainable yarns, and extending seaweed farming to cut carbon emissions, improve food security, encourage marine biodiversity and help mankind cope with climate change.
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