New nano-structured carbon materials: application in the energy storage field

The preparation of porous carbon materials is a topic which is investigated in many laboratories since such materials are attractive for applications as diverse as gas separation, water purification, catalysts supports, hydrogen or methane storage, and many others. Synthesis pathways to create porous carbons are manifold and depend strongly on the characteristics of the carbons which are targeted. Using a templating pathway, the synthesis of carbon materials with a high degree of control over their structural and textural properties can be achieved. The final characteristics like the structural, textural and surface chemistry characteristics of the carbon material are complex being not only related to the template. The nature of the carbon precursor and the impregnation way must be also taken into account. The ordered porous carbons were also successfully used in super-capacitors or as hydrogen storage medium. Hydrogen was stored in the carbon porosity by gas phase adsorption at 77 K or by electro-decomposition of water at ambient pressure and temperature. Their performance was tested and the specific capacitance as well as the hydrogen storage capacity were correlated with their structural, textural and surface chemistry characteristics. In addition to their performance, these materials are very interesting as 'model materials' due, in particular, to their controlled porosity and surface chemistry. We also showed that the formation of the carbon inside a confined space like the template porosity leads to specific properties which improve their energy storage capacity. (authors)