This project addresses the point 4.2 of the call for proposal, dedicated to electrochemical capacitors (ECs) so called supercapacitors or ultracapacitors. This point mentions that : « A major effort of research must focus on improving the energy density, including implementation of new organic electrolytes to increase the electrochemical window and security. Asymmetric or hybrid systems are other avenues to explore.”.Our goal is to double the energy density of nowadays symmetrical carbon ECs, i.e from 5 to 10 Wh/kg or 7 to 15 Wh/L. Unlike most of todays research efforts which aim at replacing carbon by other materials (oxides, nitrides, etc...), thus leading to drastic changes in fabrication process, we propose to keep the carbon electrode and simply add electroactive molecules that will be anchored at the surface of carbon, thus adding a faradic component to the double layer capacitance of carbon. This concept is not new since it has been developed for more than 5 years by the partners of this consortium as well as by other teams. However, most of the work has been done in aqueous based electrolytes. The Technology Readiness Level (TRL) is at stage 2 (Invention begins, practical applications can be invented, applications are speculative). Our goal is to apply the current knowledge to the development of devices in organic based electrolytes, and to push TRL level to stage 4 (Basic technological components are integrated to establish that they will work together), being able at the end of the project to give prototype cells to companies for initiating stage 5 of TRL (Component validation in relevant environment). Subsequently the present project is dedicated to technological developments. We want to improve the energy density of carbon-based devices in organic electrolyte by two fold. This will be achieved by keeping the same cell voltage (or slightly increasing it), almost the same double layer capacitance (EDLC) of carbon electrodes but providing an extra Faradaic capacity (and not capacitance since it is purely Faradaic) to both carbon electrodes by functionalizing the surface of carbon with judiciously chosen electroactive molecules. This concept has been successfully applied to aqueous based electrolyte using quinone based functionalized carbons. The choice of the electroactive molecules (multi-electron processes are preferred to single electron process, low molecular weight is needed, adequate active electrochemical window…), the choice of the carbon (large surface area, adequate porosity not too much affected by molecular grafting on the surface, etc…), the interaction between the molecules and carbon powder (high grafting yield, etc..) and finally the behavior of modified carbon electrodes in different organic (or ionic liquid) based electrolytes are the key points that control the final performance of the modified carbon electrodes. These requirements correspond to the 5 tasks of the project. Doubling the energy density must be achieved while keeping high power capability and long term cycling efficiency which are the bottlenecks of the proposed technology. For this purpose, a consortium gathering 4 academic laboratories (including a Canadian partner) has been set up. The 4 labs have been working together for more than 12 years with more than 30 common papers and communications and already 5 common PhD and post-docs. The consortium will take benefit from the belonging of the French labs to the French Network on Energy Storage (RS2E - http://www.energie-rs2e.com/fr) to get access to prototyping facilities to lead the concept to 1000F cells.