Coupling PEDOT on Mesoporous Vanadium Nitride Arrays for Advanced Flexible All‐Solid‐State Supercapacitors

Abstract

Tailored construction of advanced flexible supercapacitors (SCs) is of great importance to the development of high‐performance wearable modern electronics. Herein, a facile combined wet chemical method to fabricate novel mesoporous vanadium nitride (VN) composite arrays coupled with poly(3,4‐ethylenedioxythiophene) (PEDOT) as flexible electrodes for all‐solid‐state SCs is reported. The mesoporous VN nanosheets arrays prepared by the hydrothermal–nitridation method are composed of cross‐linked nanoparticles of 10–50 nm. To enhance electrochemical stability, the VN is further coupled with electrodeposited PEDOT shell to form high‐quality VN/PEDOT flexible arrays. Benefiting from high intrinsic reactivity and enhanced structural stability, the designed VN/PEDOT flexible arrays exhibit a high specific capacitance of 226.2 F g−1 at 1 A g−1 and an excellent cycle stability with 91.5% capacity retention after 5000 cycles at 10 A g−1. In addition, high energy/power density (48.36 Wh kg−1 at 2 A g−1 and 4 kW kg−1 at 5 A g−1) and notable cycling life (91.6% retention over 10 000 cycles) are also achieved in the assembled asymmetric flexible supercapacitor cell with commercial nickel–cobalt–aluminum ternary oxides cathode and VN/PEDOT anode. This research opens up a way for construction of advanced hybrid organic–inorganic electrodes for flexible energy storage.

3D Porous Honeycomb‐Like CoN‐Ni3N/N‐C Nanosheets Integrated Electrode for High‐Energy‐Density Flexible Supercapacitor

“…When the voltage window widened to 1.7 V, electrochemical polarization began to occur on the corresponding profile, indicating that the suitable operating voltage window of the FQAS is 0–1.6 V. Figure 5d presents the CV profiles of the FQAS device at different sweep rates, all the CV profiles show visible redox peaks from 1 to 100 mV s −1 , which could be derived from the combined effect of the battery‐type CoN‐Ni 3 N/N‐C/CC cathode and the pseudocapacitive VN/CC anode. [ 39,40 ] The GCD profiles of the FQAS device at increasing current densities are measured to further assess the supercapacitive performance in Figure 5e, and the nearly linear with a small curvature and approximately symmetrical charge and discharge profiles indicate the superior energy storage performance and prominent electrochemical reversibility. At the current densities of 1, 2, 5, 10, 20, 30, 40, and 50 mA cm −2 , the FQAS can achieve the excellent areal specific capacitance of 298.3, 290.6, 278.4, 265.8, 252.6, 248.4, 234.7, and 222.9 mF cm −2 (Figure 5f), respectively.…”

Emerging of Heterostructure Materials in Energy Storage: A Review

“…Otherwise, the storage mechanism of pseudocapacitors is attributed to the redox reaction and the charge intercalation process. [ 222 ] Usually, the pseudo‐capacitive materials have a high specific capacity and relatively poor long‐term cycling stability. [ 223–225 ] However, insufficient energy density is still one of the main challenges for the wide range application of supercapacitors.…”

Crystalline Co2V3O8@Amorphous Co−B Core‐Shell Nano‐Microsphere: Tunable Shell Layer Thickness, Faradaic Pseudocapacitive Mechanism, and Electrochemical Capacitor Applications

“…Figure 7d shows the relationship between the peak current and the square root of the sweep speed, showing A good linear increasing relationship, which is also a typical feature of porous electrodes. This indicates that the entire charge storage process of the electrode is controlled through surface capacitance and diffusion [58–59] . Figure 8e illustrates the distribution of the ion diffusion and capacitance process of Co 3 V 2 O 8 @Co−B‐2 at 20 mV s −1 .…”