Highly Rate Capable Nanoflower-like NiSe and WO₃@PPy Composite Electrode Materials toward High Energy Density Flexible All-Solid-State Asymmetric Supercapacitor

Abstract

An advanced novel all-solid-state asymmetric supercapacitor (ASC) device of high energy and power densities is designed on the basis of the nanoflowerlike NiSe as the positive electrode and WO 3 @PPy composite as the negative one. The porous NiSe was prepared by facile selenization of predesigned NiO nanoflowers, and the WO 3 @PPy composite was synthesized through in situ oxidative polymerization of pyrrole in the presence of dispersed WO 3 nanosticks which, in turn, was produced by a simple sulfate-assisted hydrothermal method. When tested as a supercapacitor positive electrode in the three-electrode system, the NiSe exhibits an appreciably higher specific capacitance of 1274 F g −1 at 2 A g −1 than that of the NiO nanoflower (774 F g −1 ). Again, as the negative electrode, the WO 3 @PPy composite also shows excellent electrochemical properties with a higher specific capacitance (586 F g −1 at 2 A g −1 ) than those of either of its components (WO 3 : 402 F g −1 and PPy: 224 F g −1 ). Based on these properties of the respective electrodes, a flexible ASC device was designed and fabricated by assembling the NiSe as the positive electrode with WO 3 @PPy composite as the negative electrode. The NiSe//WO 3 @PPy solid-state ASC with an extended potential window of 1.25 V demonstrates an admirable energy density of 37.3 Wh kg −1 at a power density of 1249 W kg −1 at 2 A g −1 along with outstanding long-term cycling stability that retains 91% of the initial capacitance even after 5000 charging and discharging cycles. All these results reveal the proficiency of the ASC device as a high-performance energy storage system for next-generation portable electronics.

Nanostructure Nickel-Based Selenides as Cathode Materials for Hybrid Battery-Supercapacitors

“… Das et al (2019) prepared a flower-like nickel selenide cathode material by performing a splenization reaction on porous nickel oxide materials. Besides, the WO 3 @PPy compound was obtained as a negative electrode material by the in-situ oxidation reaction of WO 3 nanorods in the presence of pyrrole.…”

Electrodeposition of Ti-Doped Hierarchically Mesoporous Silica Microspheres/Tungsten Oxide Nanocrystallines Hybrid Films and Their Electrochromic Performance

“…Thus, there exists optimal weight ratio of Na2WO4•2H2O:THMSs of 15:1 to achieve THMS/WO3 composite film with the best electrochemical performance from a trade-off between these two contradictory effects. The electric resistance is another important parameter to assess the electrochemical performance of electrochromic materials [49]. Thus, we further compared the resistance of the WO3 and THMS/WO3 film electrodes by EIS measurements, which were conducted by applying an AC voltage of 5 mV in a frequency range of 0.05 Hz to 100 kHz at their bleached state (about 0.5 V vs. Ag/AgCl).…”

“…As shown, all the plots contained a semicircle at high-frequency represented the charge-transfer impedance on the electrode/electrolyte interface, and a straight line in the low frequency region correlated with ion diffusion process within the electrode. The THMS/15WO3 hybrid films exhibited the smallest The electric resistance is another important parameter to assess the electrochemical performance of electrochromic materials [49]. Thus, we further compared the resistance of the WO 3 and THMS/WO 3 film electrodes by EIS measurements, which were conducted by applying an AC voltage of 5 mV in a frequency range of 0.05 Hz to 100 kHz at their bleached state (about 0.5 V vs. Ag/AgCl).…”

Synthesis of three-dimensional hierarchical furball-like tungsten trioxide microspheres for high performance supercapacitor electrodes

“…With the advantages of high-power density, long cycling stability, high conversion efficiency and easy maintenance, supercapacitors have become a promising candidate for renewable energy conversion and storage devices, especially in photovoltaics and wind power generation and transition. 1,2 But their application in renewable energy eld is limited by their relatively low specic capacitance and relatively high average equivalent series resistance caused by the preparation technique. 3 According to the energy storage mechanism, supercapacitor electrode materials can be classied into two types, one is electrical double-layer capacitive material and another one is pseudocapacitor material.…”