Bamboo-derived Hard Carbon/carbon Nanotube Composites As Anode Material for Long-Life Sodium-Ion Batteries with High Charge/discharge Capacities

Hard carbon derived from bamboo for the anode material of sodium-ion batteries has a three-dimensional (3D) open framework structure and has naturally incorporated K-ions into its carbon structure, increasing the d-interlayer spacing of hard carbon materials for facilitating Na+ transport. In this work, bamboo-derived hard carbon was prepared via two carbonization temperatures at 700 and 1000 °C for an hour and employed as an anode for sodium-ion batteries (SIB). X-ray diffraction (XRD) and Fourier transform (FT)-Raman spectroscopic results indicated the disordered structure with d-spacing (d002) around 0.36–0.37 nm, which is a benefit for sodium ion insertion/desertion. Herein, the composition between carbon-nanotube (CNT) and bamboo-derived hard carbon (BB) was synthesized by a ball mill with various contents of CNT (1 wt