Boosting the performance of nickel–cobalt LDH cathode with phosphorus and selenium co-doping for hybrid supercapacitor

Figures & data

Figure 1. Preparation process of P, Se-NiCo LDH and the rapid transfer of electrons and ions as well as rapid kinetics for charge separation.

Figure 2. (a) XRD patterns of NiCo LDH, Se-NiCo LDH and P, Se-NiCo LDH; High-resolution XPS of (b) P 2p; (c) Se 3d and (d) O 1s of P, Se-NiCo LDH. (e) N₂ adsorption–desorption isotherms and (f) BJH pore size distribution curve of NiCo LDH, Se-NiCo LDH, P-NiCo LDH and P, Se-NiCo LDH composites.

Figure 3. (a–d) SEM images of the NiCo LDH, P-NiCo LDH, Se-NiCo LDH and P, Se-NiCo LDH. (e) TEM observation of P, Se-NiCo LDH sample. (f) HRTEM images of P, Se-NiCo LDH sample. (g) EDS elemental mapping of P, Se-NiCo LDH composite.

Figure 4. (a) CV curves, (b) GCD profiles, (c) Nyquist plots and (d) b-values of four electrode materials. (e) Capacitance contribution and (f) Voltammetric response of P, Se-NiCo LDH electrode. (g) Cycle stability of four electrode materials at 10 A g⁻¹.

Figure 5. (a) CV curves of P, Se-NiCo LDH and AC electrodes during 10 mV s⁻¹. P, Se-NiCo LDH//AC device of (b) CV curves at 5–50 mV s⁻¹, (c) GCD curves before and after 10,000th cycles, (d) Specific capacitances at 1–20 A g⁻¹ (inset: GCD curves at 1–20 A g⁻¹), (e) Nyquist plots before and after cycle, (f) Ragone plot for comparison, and (g) Long cycle stability test at 5 A g⁻¹. Insets of (g) are the photographs of devices connected in series to trigger electronic meter and 15 red LEDs, the inset SEM image of (g) is P, Se-NiCo LDH cathode after 10,000 cycles.