Supplying more power and energy for electric vehicles

Supercapacitors are energy storage devices that can deliver power rapidly and be recharged almost infinitely without a drop in performance. They have become essential for auxiliary power in electric cars, helping them to accelerate on demand and recover energy during braking.

However, energy storage capacity or energy density of conventional supercapacitors is limited (translating to a weight issue), and they are expensive. The EU-funded AUTOSUPERCAP (Development of high energy/high power density supercapacitors for automotive applications) project addressed the need for a high-performance, low-weight power system with a low-cost target.

Work began with the definition of specific applications and their requirements, and the simulation of the automotive power system with the battery-supercapacitor storage unit. Parametric studies were carried out to study the effects of a supercapacitor on an efficient and sustainable automotive power system.

Overall, results showed that the supercapacitor greatly reduces battery ageing and also displays modest energy efficiency improvements when operating under critical climate conditions. The supercapacitor increases battery life from 400 % to 2 100 % depending on the circumstances.

Cost and life-cycle analyses were conducted for supercapacitors and power systems in electric vehicle applications in order to evaluate performance, cost, recyclability and sustainability.

Recycling protocols for the supercapacitor parts and materials were assembled and tested. It was found that recycled carbon materials such as activated carbon fabrics, multi-wall carbon nanotubes and graphenes do not suffer any additional degradation during recycling. These various forms of carbon can potentially be used for producing supercapacitors for electric vehicle applications.

AUTOSUPERCAP delivered an innovative supercapacitor that exceeds foreseen performance levels, estimated cost, sustainability and materials recycling protocols. At long last, the industry in Europe has a supercapacitor for automotive applications that is economically feasible.