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In early January, small-scale Finnish firm Verge Motorcycles took to the Consumer Electronics Show in Las Vegas to announce a world-first range of TS Pro naked roadsters, powered by solid-state batteries.
Not just a breakthrough for electric motorcycles, the announcement had the potential to change the way we consider EVs full stop – with solid-state batteries said to offer faster recharge times, greater energy storage, and reduced risk of fire when compared with traditional lithium-ion cells.
The batteries are being produced in partnership with sister company Donut Lab, with the larger of the two versions claiming up to 370 miles on a single charge, including 180 miles when plugged into the appropriate DC fast charger for 10 minutes.
Not only that, but it’s said to be able to retain over 99% of its capacity when operating at -30°C as well as temperatures exceeding 100°C.
MCN ask the battery experts
Although the inner workings of the batteries are yet to be fully disclosed, MCN sat down with Dr John-Joseph Marie, who is the Principal Analyst for Energy Storage, at the Faraday Institution to find out more about the technology.
Founded in 2017, the Faraday Institution are a Government-backed organisation that provide funding for battery technology research across the UK.
“[I can] very easily see why solid-state would be of interest to someone designing or trying to produce electric motorcycles because you are so space constrained, and you need as much of that increase in energy density as you can to be able to make it viable,” Dr Marie said.
“A conventional lithium-ion battery (the kind found in existing electric bikes) will use a liquid electrolyte. So that would typically be an organic solvent with the lithium salt dissolved in it. That allows the conduction of lithium ions between the anode and the cathode when you cycle the battery.”
He continued: “In a solid-state battery, you replace that liquid with ideally a solid electrolyte.
“Polymer lithium-ion cells are available today. You might find them in batteries for commercial drones, for example. They will have a plastic polymer based electrolyte with a lithium salt in it, and that can allow the lithium-ion conduction between the anode and the cathode. They tend to have reasonable power characteristics.
“The class of solid-state batteries, which are still under research, use different types of materials on the solid electrolytes. Those are sulphide-based electrolyte materials and oxide-based electrolyte materials.”
Beware of dendrites
According to Dr Marie, one of the biggest issues with solid-state batteries is the risk of dendrite formation, something that battery producers Donut Lab claim to have eliminated with their new design.
“One of the big reasons why people want to go to solid-state batteries is because they believe it will enable the use of lithium metal as an anode, which for a lithium-ion battery, is the holy grail material that you can have on the anode side. It will boost your energy density considerably,” the battery expert explained.
“The issue with using a metal anode is that over time, you can form these dendrites, which are essentially little hairs of lithium which stick out from the surface of the anode. If they grow, and they touch the cathode side of the cell, you can get a short circuit within the battery. A big, intense discharge of energy all at once can lead to safety issues.
“If you use a solid material, the hope is that you can suppress the dendrite formation, but lithium can still be prone to growing dendrites through these ceramics, which is why further research is still being required to help address some of those issues.”
Battery safety is important
Should the technology become more mainstream, there are a number of perceived benefits – including a reduced risk of fire. This is because the organic solvent found in the liquid electrolyte of conventional lithium-ion cells is flammable – something removed with solid-state tech.
“Solid-state batteries can have higher power density,” the Faraday representative added. “And on energy density, conventional lithium-ion cells currently use graphite anodes or maybe graphite anodes with a small amount of silicon in them.
“If you can move to a lithium metal cell (with solid-state) that is a big jump in energy density that you can achieve from a materials perspective and solid-state batteries are helping enable that.”
Verge announce bold future claims
While Verge might claim to have unlocked a 180-mile recharge in 10 minutes, Donut Lab promise far more radical specifications.
In a statement on January 5, the partly British-based company claimed that their new power unit would be capable of a full charge in just five minutes, and up to 100,000 cycles with a minimal fade in capacity.
When asked about the claims, Dr John-Joseph Marie told MCN: “I haven’t looked at it in that much detail. The numbers are flamboyant.
“I think a lot of people in the battery industry raise a lot of question marks about it. Until those numbers can be independently verified, it’s very hard to be able to comment on them.”
The MCN take
Improved charge times, increased range, and better safety are all positives that the electric motorcycle industry could benefit from. We look forward to getting our hands on Verge’s new models to see if their claims stack up on everyday British roads.
