Car manufacturers are desperate for an alternative to the combustion engine, one that is sustainable, affordable and free of compromise.
A Liechtenstein-based company called Nanoflowcell claims to have an answer: an electric car that can be filled up at the pump with non-flammable, non-toxic fluid and is said to deliver a range similar to that of conventional petrol or diesel cars.
Nanoflowcell revealed its first concept car, the Quant E, at last year’s Geneva motor show. This year it returned with the Quant F and much smaller Quantino two-seater. All three cars are propelled by four wheel-mounted electric motors supplied with electricity from a flow cell battery.
The flow cell concept is based on the Redox (reduction and oxidation) flow cell technology trialled by NASA in the early 1970s. Redox flow cells generate electricity when fed with two electrolytic fluids, one positively charged and one negatively charged, stored in separate tanks.
The flow cell is split into two halves by a membrane, with positively charged electrolyte flowing through one side and negatively charged through the other. Ion exchange takes place through the membrane, generating an electric current.
Normally, flow cells can be replenished by recharging like any other battery, or simply by replacing the fluid. The Nanoflowcell works differently. As it discharges, the water-based ‘ionic’ fluid electrolyte evaporates, leaving the storage tanks empty and ready for refilling. Quant cars can be refuelled at a pump using a two-pronged nozzle to fill both the ‘positive’ and ‘negative’ tanks at the same time.
According to chief technical officer and inventor of the Nanoflowcell Nunzio La Vecchia, “the ionic fluid is non-flammable and non-toxic, and there are no emissions or high pressures involved”. As a result, he adds, on-board storage is straightforward and establishing a filling station network simple and relatively cheap.
Traditional flow cell designs don’t have the greatest volumetric energy density, which means a large volume is needed to store a reasonable amount of energy. Nanoflowcell claims its new fluid formulation improves this, giving five times the energy capacity of a conventional flow cell. La Vecchia says 80% of the development so far has gone into improving the chemistry of the ionic fluids and 20% into the design of the flow cell.
The Quant F has a range of 497 miles and the Quantino 621 miles, but Nanoflowcell concedes they still need to carry a substantial amount of fluid – 500 litres in the case of the Quant F – in two 250-litre tanks weighing half a tonne. The Quantino carries 350 litres of fuel, which weighs around 350kg. By comparison, a Range Rover TDV6 carries 85 litres of diesel weighing 72kg.
That said, unlike petrol, diesel or hydrogen, liquid fuel is easy to distribute throughout the structure of a car if necessary, especially if it is as harmless as Nanoflowcell claims.
A flow cell is good at producing a steady stream of energy but not the transient spikes of power demanded by a driver. So the Nanoflowcell feeds power to a 2000A supercapacitor acting as a buffer to deliver instant power to the four wheel motors in response to the accelerator pedal.
The flow cell is powerful, with the Quant F’s system generating 735V and 92A. The Quantino, though, has an intrinsically safer low-voltage system, just 48V but “more than 200A”. In real terms, that means the system can deliver enough electrical energy to power four 25kW, 134bhp electric motors and deliver a quoted top speed of more than 125mph. By comparison, a Nissan Leaf’s battery produces 360V.
The Quant E gained TÜV Süd approval to be driven on public roads last year, and the company is now seeking homologation for the Quant F, allowing it to enter production. “One hundred per cent of the exterior qualifies and we are 90% there with the interior,” says La Vecchia. The Quantino, with its low-voltage system, is also being prepared for homologation. The next stage in the process is crash testing, and La Vecchia hopes homologation will be completed next year.