Fig. 3. Electrochemical performance of the 3D Ni(HCO3)2/rGO. (a) Cyclic voltammograms recorded at a scan rate of 0.1 mV s–1; (b) galvanostatic discharge/charge profiles of the 1st, 2nd, 10th, and 100th cycle at a current density of 0.1 A g–1; (c) rate capability at various current densities (from 0.1 A g–1 to 40 A g–1); (d) Nyquist curves of electrochemical impedance spectra before cycling, after the 100th cycle and after the 2000th cycle at a current density of 10 A g–1; (e) long-term cycling performances at a current density of 5 A g–1 and 10 A g–1.
