A new type of electric car technology that uses a combination of battery and hydrogen power has an energy density so high it could allow a passenger car to travel over 5000km, only stopping to quickly refill the battery fluid.
While there remains a lot of contention between the pros and cons of using hydrogen to power zero emission vehicles versus lithium-ion battery electric powered vehicles, breakthroughs like this continue to bring the topic to the fore.
Using a patented “flow” system that creates electricity via a single fluid to power a vehicle, as well as producing hydrogen as needed, the technology is currently being tested at Purdue University, Indianapolis using golf carts.
The system is similar to the Scottish “flow battery” technology that hit the news last year; although that system uses a membrane to pass ions through two separate “containers” of fluids, whereas the new system has no membrane and uses just one “container” of fluid.
The single fluid system allows a much greater energy density to be achieved, John Cushman, Purdue University distinguished professor of earth, atmospheric and planetary sciences and a professor of mathematics said in a statement to the press.
This would mean lighter batteries and greater range for electric vehicles, and could put flow batteries on the table as a serious contender for powering EVs.
“Historically, flow batteries have not been competitive because of the low energy density,” Cushman said. “For example, conventional flow batteries have an energy density of about 20 watt hours per kilogram. A lithium-ion battery runs on 250 watt hours per kilogram. Our flow battery has the potential to run between three and five times that amount.”
Also, the new tech allows the hydrogen produced to be stored at much less pressure, said Michael Dziekan, senior engineer for the commercialisation company IFBattery, explained in a statement.
“The battery does two things: it produces electricity and it produces hydrogen. That is important because most hydrogen-powered cars run on a 5,000 or 10,000 PSI [pounds per square inch] tank, which can be dangerous,”he said.
“This system generates hydrogen as you need it, so you can safely store hydrogen at pressures of 20 or 30 PSI instead of 10,000.”
The system so far has been tested on scooters and golf carts, and based on the tech advances being developed the researchers think that 3,000-3,600 miles (about 4,800-5,800km) range could be achieved.
The only reason drivers would need to stop – other than for a coffee, toilet break and presumably to swap drivers! – is to change over the battery fluid every 480km or so, much like refuelling for petrol as opposed to the 45 minutes or so needed at a fast charger for li-ion battery electric cars.
This could be done in a very similar process to stopping for petrol, the researchers say – in fact, the system could potentially be retrofitted into existing service station dispensers.
“The jump that this technology has made in the past two years is a testament to its value in changing the way we power our vehicles,” said Cushman.
“It’s a game-changer for the next generation of electric cars because it does not require a very costly rebuild of the electric grid throughout the US. Instead, one could convert gas stations to pump fresh electrolyte and discard depleted electrolyte and convert oil-changing facilities to anode replacing stations. It is easier and safer to use and is more environmentally friendly than existing battery systems.”
Once the anode is spent – about every 5,000km – it can simply be replaced in about the same time as doing an oil change and for an approximate cost of about $US65 ($A90).
“We are at the point now where we can generate a lot of power. More power than you would ever guess could come out of a battery like this,” Cushman said.
The potential for reusing the components and fluid is also an attractive benefit – they can be gathered and then recharged at a renewable energy plant such as a solar farm or wind turbine.
“It is the full circle of energy with very little waste,” Cushman said. “IFBattery’s components are safe enough to be stored in a family home, are stable enough to meet major production and distribution requirements and are cost-effective.”