Dicyanobenzoquinone Functionalized Carbon Nanotubes As Cathode Materials for Rechargeable Lithium and Sodium Ion Batteries

Currently, lithium ion batteries (LIBs) and sodium ion batteries (SIBs) mainly depend on inorganic cathode materials, which are still plagued by several issues restricting their advancement such as power density, sustainability, and safety. As alternatives, organic electrode materials have been intensively investigated for both LIBs and SIBs due to their advantages of sustainability, flexibility of structure design and environmental friendliness. Among them, organic quinone materials offer a sustainable approach for electric energy storage, however, their intrinsic electrical insulation and dissolution into the electrolyte during cycling have hampered their wide application. To tackle these two issues, we have synthesized novel organic cathode materials by anchoring a quinone compound, 2,3-dicyano-p-benzoquinone (DCBQ) with a high redox potential of 3.37 V vs. Li/Li+, onto carbon nanotubes (CNTs) (CNTs-DCBQ) through a facile ‘‘grafting to’’ method. The elaborate combination of excellent electron conductivity and large surface area of CNTs and stable and reversible redox reaction of DCBQ enables CNTs-DCBQ delivering high reversible capacities of 206.9 and 175.8 mA h g-1 at a current density of 10 mA g-1 and also remarkable capacities of 110.2 and 82.1 mA h g-1 at a higher current density of 200 mA g-1 with a capacity retention approaching 100 % after 1000 cycles for lithium and sodium ion batteries, respectively.