Powering electric cars – battery or capacitor?

Powering electric cars – battery or capacitor?

The Guardian has recently reported about researchers in the UK have developed a new polymer to make supercapacitors that could one day replace batteries in electric cars. They claim that the technology could result in electric cars that could travel as far as petrol and diesel vehicles. Another significant advantage is that they could be charged up very quickly; in 10 minutes, compared to the 8 hours it takes to charge lithium-ion batteries in today’s electric vehicles.

The research teams believe that the polymer is more ‘energy dense’ than lithium ion batteries holding 180 watt-hours per kilogram compared with 100 – 120 watt-hours per kilogram for lithium ion.

At this stage, the new polymer has only been used on a very small scale to power a tiny fan or LED. This new technology is yet to be scaled-up for use on vehicles and its cost effectiveness and sustainability have not been tested.


Users of the STELR Solar Car kits will know that they are fitted with a conventional capacitor that can be charged up from the solar panels or a battery. This allows the solar car to be powered either directly from the Sun or from the capacitors stored charge.

You can hear an interview about the use of supercapacitors to store electrical energy in your home that was aired on ABC Radio Melbourne on 7 March 2018 here.