By replacing common lithium-ion batteries with supercapacitors, it will be possible to get a “full charge” in under a minute. Electric cars, however, will see their range reduced.
In the United States, the main reason people forgo purchasing an electric vehicle is not related to the shorter range compared to a petrol or diesel model, nor to the lack of widespread charging points. In the States, motorists who might otherwise consider a battery-powered car an attractive option are put off above all by the long charging times. A problem that, in the medium term, high-capacity stations may help alleviate, while awaiting certain technologies currently under development that could make a "full charge" almost instantaneous.
According to a study conducted by Bloomberg in California, Florida, Minnesota, Delaware and Connecticut – some of America's wealthiest states – the fact that batteries take several hours to charge is seen as a major drawback by the majority of potential electric car users. In this regard, the Obama administration allocated 4.5 billion dollars towards the creation, by 2020, of a fast-charging network, including a feasibility study for the construction of 350 kW charging points. A remarkable figure, especially considering that Tesla Superchargers, currently among the fastest and most powerful battery regeneration systems in the world, operate at a maximum of 120 kW, equivalent to around 270 km of range in 30 minutes. 350 kW has also become the target in Europe thanks to the joint venture between some of the leading manufacturers. An agreement that is expected to result, from 2017, in 400 ultra-fast stations along the main motorways of the Old Continent. But is all of this enough?
Charging batteries in under a minute may no longer be a pipe dream. Two university research projects, developed in England and Florida respectively, could make a "full charge" competitive with a conventional fossil fuel fill-up, even in terms of speed. In the first case, the new technology is based on the adoption of supercapacitors in place of conventional batteries. The devices used for energy conversion and storage are characterised by high specific power, far superior to that of lithium-ion accumulators, but with low energy density — that is, a lower storage capacity per kilogram. A "drawback" that would result in the range of electric cars being halved. On the other hand, according to research developed by the company Augmented Optics in collaboration with the universities of Surrey and Bristol, the charging speed would be a thousand to 10,000 times faster than current speeds. A flash!
The first prototype of a zero-emission propulsion system powered by supercapacitors is set to emerge in 2017 and could reach mass production in a relatively short time, given that these components do not use precious materials — meaning they have a reasonable cost — require no maintenance, and can count on a useful service life longer than that of conventional batteries. The University of Central Florida also believes in supercapacitors. In this case, however, the heart of the new technology would be innovative two-dimensional winding materials, made up of millions of microscopic filaments that would increase energy density while reducing the range degradation of vehicles. An innovation that would, moreover, bring useful charge cycles from 1,500 to over 30,000. The American research is still some way from mass production, at least as far as the automotive world is concerned, whereas within five years it could become the standard for smartphones and portable devices.
Perhaps supercapacitors will not replace conventional chemical batteries, but they could become an opportunity for car manufacturers to broaden their offering and for motorists to meet their varying zero-emission mobility needs. In any case, the environment would be grateful.