Fig. 1. Assembly process diagram of HQ@PVA@ACNT composite redox-enhanced solid-state super capacitor device.

Fig. 2. (a) The SEM image of CCNT; (b) the SEM image of ACNT (insert: The TEM image of ACNT); (c) preparation process of the DACNT; (d) comparison of the arrays before and after shrinkage; (e) the SEM image of the DACNT; (f) the SEM image of the ACNT@PVA@HQ composite device.

Fig. 3. Electrochemical performance test of ACNT@PVA@HQ composite devices at different concentrations: (a) Comparison of CVs with different amounts of HQ addition under the same scan rate (20 mV/s); (b) area specific capacitance at different HQ concentrations; (c) GCD curves comparison diagram under the same current density (1.23 mA·cm^–2); (d) alternating current impedance spectrogram of the samples at different concentrations; (e) the diagram of equivalent circuit fitting model; (f) comparison of Ragone plots between the devices of ACNT@PVA@HQ (0.1 mol/L) and ACNT@PVA

Fig. 4. Electrochemical performance test of the ACNT@PVA@HQ composite device at [HQ] = 0.1 mol/L: (a) CV curves at scan rates from 5 mV/s to 50 mV/s; (b) GCD curves under different current densities (0.615−6.15 mA·cm ^–2); (c) relationship between peak current and scan rates; (d) the proportion of capacitance contribution in composite device; (e) Nyquist plot at 0.01 Hz−100 kHz; (f) cyclic performance (5000 cycles) during charging-discharging cycles

Fig. 5. Electrochemical test of CCNT@PVA@HQ, ACNT@PVA@HQ and DACNT@PVA@HQ composite devices:　(a) Comparison of GCD curves with 1 mA; (b) CVs comparison diagram at 20 mV/s; (c) relationship between area specific capacitance and current densities; (d) comparison diagram of EIS; (e) Ragone plots of three kinds of composite device