Sodium-ion battery is a prospective alternative for lithium-ion batteries due to its abundance of sodium crust and high theoretical capacity, and now a British research team has managed to develop a new separator material for batteries using seaweed, which not only elevates battery capacity but also enhances endurance.

Lithium-ion battery is regarded as the current leader in battery energy storage system, with maturity in technology and the most popularized applications such as tech products, EVs, and energy storage systems. With that being said, lithium mine is comparatively scarce and high in excavation cost. The International Energy Agency (IEA) had previously pointed out that the supply according to existing lithium mine and scheduled establishment by 2030 would merely fulfill 50% of the demand, and the same report also discovered that it would take an average of 16.5 years for development if operation began between 2010 and 2019.

However, sodium-ion batteries, similar to lithium-ion batteries, would encounter dendrites during charging and discharging, where uneven deposition results in dendrites breaking through the separator and eventually leads to battery short circuit. Jing Wang, lead author of the thesis, commented that a separator separates the cathodes and anodes of batteries, and allows batteries to freely transfer electric charges.

University of Bristol, Imperial College London, and University of London have joined hands on extracting cellulose from brown seaweed that is used as a new separator material for sodium-ion batteries, and claim that the particular material not only prevents from forming dendrites in electrodes, but also elevates battery performance. Wang pointed out that the seaweed material reinforces the separator that will avoid penetration from dendrites. In addition, the new separator also increases battery capacity and efficiency, as well as extends the lifespan of the battery, which helps with development of equipment in the future such as smartphones.

As pointed out by the test of the research team, the new battery was able to retain a high energy density throughout 1,000 cycles of charging and discharging, and attained an unprecedented prolonged duration of stability. This technology can also benefit other batteries, and the research team is currently attempting to expand the production scale of the aforementioned separator.

Professor Amaka Onyianta of the Bristol Composites Institute commented that it is a major achievement seeing that these nanomaterials are able to strengthen separator materials and increase capacity of lithium-ion batteries, since it indicates that the dependency on rare materials such as lithium is no longer obstinately high.

 (Cover photo source: pixabay)