Anthraquinone Functionalized Reduced Graphene Oxide As Electrode Material for Aqueous and Non-Aqueous Rechargeable Batteries

Abstract

The use of electro-active organic compounds as electrode materials in rechargeable batteries has been a very active research topic due to their high theoretical capacity, availability of various redox potentials depending on the electro-active group, ease of modification of properties, and improved safety. However, the issue of solubility in electrolytes limits their applications in batteries. The most common solutions for this problem involve incorporation of these organic molecules into the insoluble polymeric structures and trapping of these inside porous carbon materials. Here, we have demonstrated the covalent attachment of anthraquinone (AQ) derivatives via nitrene chemistry onto reduced graphene oxide (RGO) as another alternative. The successful synthesis of the RGO functionalized with anthraquinone groups (RGO-AQ) and its utilization as cathode materials in Li-batteries have also been demonstrated. The cells with RGO-AQ used as cathode materials initially discharged 126 mAh/g when cycled between 1.8-3.2V at the rate of 5.35mA/g in LiPF6/ EC:DEC (1:1) electrolyte, and discharged 185.7 mAh/g when cycled between 1.3-3.6V against Li metal at the rate of 6.0 mA/g in LiClO4/ PC electrolyte. The AQ-RGO has been used also as an anode material against in an aqueous battery against NiOOH (AQ-rGO | 30% NaOH | NiOOH). This battery provided a capacity of 140 mA/h at 0.83V and displayed a very good rate capability. Figure 1