Slowly but surely, the transition to electric vehicles (EVs) is becoming more economic. Since 2010, the battery cost per kilowatt hour has collapsed from $1000 to to just over $200, suggesting that soon EVs could reach price parity with internal combustion engine vehicles.
Among the barriers for many potential buyers is range anxiety: the worry that the battery in our car simply will not get us to our destinations.
But there could be a new technology on the horizon to help ease the transition from fossil fuels, if one former Naval engineer is to be believed. Trevor Jackson is pioneering a new hybrid battery and fuel based on aluminium-air technology, or “Al-air” for short. If his calculations are correct, an equivalent EV running on al-air batteries could travel as far as 2400km before needing replacement.
His company, Metalectrique, is a small operation, with seven shareholders who provided the seed capital and two engineers. Now Jackson is trying to raise $12 million to take the technology further.
The drawback of Jackson’s system is that al-air batteries cannot be recharged. The batteries consume fuel just as a traditional car burns petrol, albeit with zero emissions. But Jackson suggests that the upside of his solution is that consumers swap out the batteries at what we used to call gas stations, in as little as 90 seconds, enabling motorists to quickly continue their journey.
“Instead of charging, you refuel it,” he explains.
The underlying technology isn’t new, and Jackson first worked on the technology back in the 1970s when working for British Aerospace (now BAE Systems) on propulsion systems for submarines. What Jackson hit upon, however, was making a change to the chemistry inside the battery.
Simply put, the way batteries work is that there are two ends to each battery, the anode and the cathode. Electrons – the electrical charge that makes our devices work – want to cluster at one end, but the electrolytes prevent travel. When we complete the circuit by switching on whatever we’re powering, the electrons have another route – and the electrical charge runs through our lights, or motors, powering them in the process.
“My main contribution was to change the electrolytes, which was the working fluid of the battery. And by changing it, the cost basis became suitable for business,” Jackson explains. Exactly what he has done is a patented secret, but he says he came up with a new electrolyte solution that means that al-air batteries do not have to use pure aluminium, which is significantly more expensive.
He points to an Israeli start-up called Phinergy for which is also developing al-air technology. “They’re using pure aluminium, which is £100 a mile,that’s not a business,” he says. By contrast, he believes this his solution could mean fuel costs as little as 6 to 8 pence per mile, once reselling waste from the production process – which is simply commodity aluminium – is factored in.
So could Al-Air be the next big thing for electric vehicles? Energy transition consultant Melvin van Melzen, who runs energy service provider All In Power, sees opportunity, but also challenges.
“Al-air has great potential, but the technology is not nearly as mature as Lithium ion batteries,” he says, “Proving a technology in a table-top prototype is a great start, but scaling and getting quality and consistency to standard takes a lot.”
He also sees potential environmental benefits from Al-air: “Lithium is the lightest of metals but is somewhat restricted in availability and there are concerns for the environmental impact of Lithium and rare earth metals,” he explains, adding that “Aluminium is [more widely] available and its production could be better governed”.
The biggest challenge, in van Melzen’s view, is the infrastructure required for swapping batteries, because of the logistics and personnel required compared to lithium-ion charging infrastructure that can operate largely without human intervention.
“Swapping then, in my opinion, is something that would best suit fleet owners that always come back to base like regional postal trucks, garbage trucks, busses, and ferries,” he says.
This perhaps explains Metalctrique’s first target. Jackson has been talking to a German-Italian consortium that owns Tuk-Tuks, or motorised rickshaws which typically operate taxi-style services. According to his calculations, a Tuk-Tuk could drive for an entire week on just one aluminium-air battery. As part of the roll-out, there would be a central maintenance building where Tuk-Tuk drivers could go to get their battery changed and other maintenance completed – setting them up for another week’s work.
And it is when discussing this that you can see Jackson’s real vision begin to emerge: He explains that to buy the aluminium his batteries use it costs around $1500 per tonne – but one of the waste products from vehicles is “high-purity” aluminium – which in turn sells for around $23,000/tonne. So the cost of 4 cents per mile can be offset by the company making around $1.19 per mile in income from selling the scrap.
So how come the world seems set on lithium-ion batteries? Jackson blames lobbyists and mining interests, and argues that lithium technology is inherently inferior because of the energy density problem.
“A rechargeable battery in a car doesn’t make any sense from an engineering or mobility point of view because you can’t put enough energy into the battery,” he says. “It’s like a massive phone with four wheels, you can’t drive plugged into a wall!”
But Jackson’s rival technology is getting better too.
“Rapid charging technology is improving with great strides,” says van Melzan, “Expect 300 kW charging before any Al-air batteries go to market. At 300 kW you add 250km in 10 minutes. That’s hardly enough time for a relief break.”
So if the technology reaches that point, will Al-air still be worth it?
“If somebody comes up with a very fast, rechargeable battery that contains enormous amounts of energy compared with lithium-ion, then yeah, we’ll stand aside,” he says, “But I think for now, for maybe the next 20 to 50 years, [Al-air] will probably be a good, boring, reliable supply of motive power.”
