Disordered 3D Multi-layer Graphene Anode Material from CO2 for Sodium-Ion Batteries

We report the application of disordered 3D multi-layer graphene, synthesized directly from CO2 gas through a reaction with Li at 550 degrees C, as an anode for Na-ion batteries (SIBs) toward a sustainable and greener future. The material exhibited a reversible capacity of approximate to 190mAhg(-1) with a Coulombic efficiency of 98.5% at a current density of 15mAg(-1). The discharge capacity at higher potentials (>0.2V vs. Na/Na+) is ascribed to Na-ion adsorption at defect sites, whereas the capacity at low potentials (<0.2V) is ascribed to intercalation between graphene sheets through electrochemical characterization, Raman spectroscopy, and small-angle X-ray scattering experiments. The disordered multi-layer graphene electrode demonstrated a great rate capability and cyclability. This novel approach to synthesize disordered 3D multi-layer graphene from CO2 gas makes it attractive not only as an anode material for SIBs but also to mitigate CO2 emission.