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Graphene hydrogels with high electrical conductivity were prepared by a one-step process using hydrazine hydrate as gel assembly agent (GH-HD). Conventional two-step process of gel formation and further reduction to prepare highly conducting gels was replaced by a single step involving equivalent amount of hydrazine. Optimized graphene oxide concentration was established to facilitate such monolith formation. Extensive characterization and control studies enabled understanding of the material properties and gel formation mechanism. The synthesized gel shows a high electrical conductivity of 1141 S/m. The supercapacitor based on GH-HD delivers a high specific capacitance of 190 F/g at a current density of 0.5 A/g and 123 F/g at very high current density of 100 A/g. Furthermore, excellent power capability and cyclic stability were also observed. 3D macroporous morphology of GH-HD makes it ideal for high rate supercapacitor applications. [ABSTRACT FROM AUTHOR]

In order to reduce the environmental impact of human activities especially transportation and portable electronics, a more sustainable way is required to produce and store electrical energy. Actually lithium battery is one of the most promising solutions for energy storage. Unfortunately this technology is based on the use of transition metal-based active materials for electrodes which are rare, expensive, extracted by mining, can be toxic and hard to recycle. Organic materials are an interesting alternative to replace inorganic counterparts due to their high electrochemical performances and the possibility to produce them from renewable resources. A quinone derivative is synthetized and investigated as novel active material for rechargeable lithium ion batteries which shows higher performances. [ABSTRACT FROM AUTHOR]