fig5

Figure 5. Electrochemical sodium-storage characteristics of FR-HC and R-HC-x electrodes. CV curves at a scan rate of 0.5 mV s^-1 (A); Initial galvanostatic charge-discharge profiles at 0.1 A g^-1 (B); Contributions of the slope and plateau regions to the second-discharge capacity (C); Rate performance (D); Cycling stability at 0.1 A g^-1 (E); Long-term cycling performance at 0.5 A g^-1 (F); Comparison of reversible capacity and cycling durability of the present hard carbon anode with previously reported biomass-derived hard carbon materials (G). FR: Fresh reeds; CV: cyclic voltammetry; ICE: Initial coulombic efficiency.