Lithium-Ion (The Present) vs Lithium-Sulfur (The Future)
Currently, electric vehicles are powered by lithium-ion batteries. These types of batteries are used commercially in pretty much every electrical household object that doesn’t need to be plugged into the mains 24/7. They’re stable, reliable and have a predictable cycle-life (how many times they can be charged and discharged). Their energy density isn’t great if compared with its lithium-sulfur counterpart, though.
The lithium-sulfur battery is nigh-on the inverse of a conventional battery. They currently have instability issues due to the way their cathodes warp during the charge process – changing in size by 78% every cycle. This flaw increases the overall degradation of the battery massively. An electric vehicle with lithium-sulfur batteries – at least in their current state – would only get around 10 charges before they all had to be replaced.
However, they hold a huge amount of charge. Up to five times more. Introducing them on a commercial scale would have a massive impact on electric vehicles and make the term ‘range anxiety’ a relic of the past.
The team at UoM have weaved recycled Kevlar into a network of nanofibres, mitigating many of the aforementioned issues with lithium-sulfur batteries. Research has also turned to the possibility of a flexible cathode, one that is designed to deform as the battery cycles through charges.
Scientists’ focus now is to refine and research ways to stabilise the battery and reduce the purchase cost. The latter of which should be easier to achieve than with lithium-ion, as the materials needed for lithium-sulfur are more abundant and less environmentally damaging to acquire.
If achieved then, it will result in a lithium-sulfur battery with a lifespan of 1,000 charge cycles. Each cycle will allow an electric vehicle to do an incredible amount of mileage before needing to be charged, and it’ll be better for the environment. Sign us up.