The project aimed to study and develop a new 1 kW high energy density supercapacitor, based on high capacitance electrode materials and solid proton- conducting polymer electrolytes. The special combination of characteristics (2000 W/kg, 30 kJ/kg, 100,000 cycles) sought by the project would enable the supercapacitor to meet the requirements of applications such as electric vehicles. Supercapacitors are electrochemical energy storage devices. They can store several hundred times more energy, on a weight and volume basis, than conventional electrolytic capacitors while retaining the ability to deliver the energy at very high discharge rates. This means that they can outperform batteries in applications which require discharge rates in the minutes to seconds range. By combining a supercapacitor with a battery in a hybrid vehicle, for example, the benefit of the supercapacitor can be maximised. This is because the supercapacitor performs the load levelling function for the battery by providing the power demands required by the vehicle when starting, accelerating, driving uphill and regenerative braking. Such a combination prolongs the life of the battery. Supercapacitors are also very reliable and compact which makes them ideal for use in vehicles.