Over in the US, a team of scientists are testing a new type of car technology that could enable an EHV passenger car to travel more than 3000 miles with only a quick stop to refill battery fluid.
Led by professor John Cushman at Purdue University in Indianapolis, the team has combined both battery and hydrogen power to create this technology that has the potential to revolutionise the EHV industry.
There are, of course, various pros and cons to using hydrogen to power zero emission vehicles compared with lithium-ion battery electric powered vehicles but this latest “refillable” development has really got people talking.
The technology employs a patented ‘flow’ system to create electricity using one single fluid. This powers the vehicle and produces hydrogen at the same time as required. Observers have likened it to the flow battery developed by chemists at the University of Glasgow. However, the Scottish flow battery system uses a membrane to pass ions through two different compartments of fluid rather than one. This latest system doesn’t require a membrane either, so there are two clear differences.
What is a flow battery?
A flow battery is a kind of electromechanical cell where chemical energy is delivered by two chemical components dissolved in liquids. Flow batteries are of specific interest in the EHV industry because they can be used in various applications as they work like a fuel cell or rechargeable battery.
Single fluid system
There are several benefits to a single fluid system, according to Professor Cushman. First of all, it facilitates a much greater energy density.
Flow batteries have previously been deemed uncompetitive as a result of their low energy density. A conventional flow battery will only have an energy density of around 20watt hours per kilogram whereas a lithium-ion battery operates at 250watt hours per kilogram.
What’s exciting is that the new flow battery tech could conceivably run up to five times that figure, translating into far lighter batteries and a far greater range for EHVs in the future. Plus, the system allows the hydrogen that is produced to be safely stored at a lower pressure than ever before – around 20 or 30 PSI rather than 5,000 or 10,000 PSI as is currently demanded by hydrogen-powered cars.
Extending the range
The research team has installed the single fluid, membrane-free flow battery in a golf cart and, based on a variety of tests, they believe that a range of 3,000 – 3,600 miles is conceivable. If that range can be achieved, it will be a significant milestone in the development of EHVs.
To put this into perspective, take a look at the official range, on one single charge, of some of the world’s most popular electric vehicles:
Volkswagen e-Golf 144 miles
Nissan Leaf 168 miles
Hyundai Kona Electric 279 miles
Drivers of any vehicle that incorporates the new tech would still have to make stops every 300 miles or so to change the flow battery’s fluid (and grab a coffee!). It is envisaged that this process could be as simple, and as quick, as filling a traditional petrol or diesel car with fuel. At present, EHV drivers need to schedule a minimum of 45 minutes at a fast-charging point for lithium-ion battery powered cars.
A game changer
Heralded as a game changer for the future design and manufacture of EHVs, what makes the new tech even more attractive is it doesn’t demand an expensive refit of the existing charging or fuelling structure. Petrol stations could be retrofitted or converted to facilitate the refill of fresh electrolyte and discard of used electrolyte. Anodes could also be replaced every 3000 miles on the same site and at the same time as an oil change. A new anode for the system would cost around £50.
There’s an added benefit to the new tech too: it ticks environmental and recycling boxes. Used electrolyte, fluids and other components can be collected and recharged at a renewable energy plant including wind and solar farms. They can then be readily reused. With little waste, safe and stable capacity for mass production and offering cost effective distribution and implementation, here at Prosol UK we’ll be keeping a close eye on how this innovative battery tech charges forward.