All-Solid-State Flexible Asymmetric Supercapacitor with Good Cycling Performance and Ultra-Power Density by Electrode Materials of Core-Shell CoNiO2@NiAl-Layered Double Hydroxide and Hollow Spherical α-Fe2O3

Abstract

High electrochemical performance of asymmetric supercapacitor (ASC) depends on exquisite nanostructure design and synthesis of electrodes, including structural controllable design and synthesis of high theoretical performance materials and nanocomposite materials. Herein, a template-free hierarchical core-shell nanostructure of CoNiO2@NiAl-layered double hydroxide (NiAl-LDH) and α-Fe2O3 with a hollow spherical structure composed of nanoparticles are successfully prepared. The CoNiO2@NiAl-LDH as the cathode electrode and the hollow spherical α-Fe2O3 as the anode electrode of the ASC devices exhibit superior electrochemical performance. The gel of polyvinyl alcohol (PVA) and KOH acts as the solid electrolyte and the separator to assemble into the all-solid-state flexible ASC devices. Two of the CoNiO2@NiAl-LDH//α-Fe2O3 ASC devices in series are fabricated to meet the voltage requirement of mobile energy equipment, which exhibit a maximum energy density of 65.68 Wh kg−1 at the power density of 369.45 W kg−1. Interestingly, in addition to many advantages that the solid electrolyte in ASC devices already have, we find that it can be an alternative way of solving the problem of iron oxide cycling performance, and of course it can also be used as a reference for other materials with poor cycling performance.

Effect of SiO2/Al2O3 ratio on the electrochemical performance of amorphous zeolite loaded with cobalt oxide grown via steam-assisted crystallization method

“…These GCD curves displayed non-linear shapes, thus, exposing the faradaic behaviour of both electrodes. 53 Fig. 9 displayed the specific capacity at different scan rates for all the samples.…”

High selectivity and sensitivity through nanoparticle sensors for cleanroom CO2 detection

“…All prominent standard diffraction peaks conforming the formation of CoNiO 2 have been observed in recorded XRD spectra (JCPDS No. 10-0188) [20][21][22]. Diffraction peaks at 37°, 43°, and 63°are ascribed to (111), (200), and (220) planes of the CoNiO 2 phase, and a minor diffraction peak at around 45°can be indexed to the NiCo 2 O 4 phase (JCPDS No.…”

Advances in pseudocapacitive and battery-like electrode materials for high performance supercapacitors

“…High-performance asymmetric SCs have been fabricated using Fe 2 O 3 as the negative electrode. For instance, Zhang et al 162 reported the electrochemical performance of an asymmetric SC manufactured by using oxides and layered double hydroxides (LDHs). The devices consisted of a core–shell structured CoNiO 2 @NiAl-LDH composite as positive and α-Fe 2 O 3 as negative electrode.…”