Functionalized graphene foam as electrode for improved electrochemical storage

Abstract

We report on a non-covalent functionalization of graphene foam (GF) synthesised via chemical vapor deposition (CVD). The GF was treated with pyrene carboxylic acid (PCA) which acted as a source of oxygen and/ or hydroxyl groups attached to the surface of the graphene foam for its electrochemical performance improvement.The modified graphene surface enabled a high pseudocapacitive effect on the GF. A specific capacitance of 133.3 F g -1 , power density ∼145.3 kW kg -1 , and energy density ∼4.7 W h kg -1 was achieved based on the functionalized foam in 6 M KOH aqueous electrolyte. The results suggest that non-covalent functionalization might be an effective approach to overcome the restacking problem associated with graphene electrodes and also signifies the importance of surface functionalities in graphene based electrode materials.

Reactive copolymer functionalized graphene sheet for enhanced mechanical and thermal properties of epoxy composites

“…After functionalization with VCz–GMA, the D‐band and G‐band was red shifted to 1345 and 1599 cm −1 , respectively, suggesting an interaction between the graphene sheet and VCz–GMA copolymer. Similar red shift of Raman peaks of graphene after noncovalent functionalization has also been reported in previous literatures …”

A high energy density asymmetric supercapacitor utilizing a nickel phosphate/graphene foam composite as the cathode and carbonized iron cations adsorbed onto polyaniline as the anode

“…The graphene foam (GF) were prepared according to our recent work. 25,26 Briey, the Ni foam (NF) was placed at a centre of a CVD quartz tube. Before graphene growth, the nickel foam was annealed at 1000 C under a mixture of argon (Ar) and hydrogen (H 2 ) gasses for 60 min.…”