Highly Stable Gully-Network Co3O4 Nanowire Arrays as Battery-Type Electrode for Outstanding Supercapacitor Performance

Abstract

3D transition metal oxides, especially constructed from the interconnected nanowires directly grown on conductive current collectors, are considered to be the most promising electrode material candidates for advanced supercapacitors because 3D network could simultaneously enhance the mechanical and electrochemical performance. The work about design, fabrication, and characterization of 3D gully-network Co3O4 nanowire arrays directly grown on Ni foam using a facile hydrothermal procedure followed by calcination treatment will be introduced. When evaluated as a binder-free battery-type electrode for supercapacitor, a high specific capacity of 582.8 C g−1 at a current density of 1 A g−1, a desirable rate capability with capacity retention about 84.8% at 20 A g−1, and an outstanding cycle performance of 93.1% capacity retention after 25,000 cycles can be achieved. More remarkably, an energy density of 33.8 W h kg−1 at a power density of 224 W kg−1 and wonderful cycling stability with 74% capacity retention after 10,000 cycles can be delivered based on the hybrid-supercapacitor with the as-prepared Co3O4 nanowire arrays as a positive electrode and active carbon as negative electrode. All the unexceptionable supercapacitive behaviors illustrates that our unique 3D gully-network structure Co3O4 nanowire arrays hold a great promise for constructing high-performance energy storage devices.

Simple Preparation of Porous FeCo2O4 Microspheres and Nanosheets for Advanced Asymmetric Supercapacitors

“…While for FeCo 2 O 4 NSs//AC ASC, it exhibited a high energy density of 37.1 W h kg –1 at 928.0 W kg –1 and still maintained 23.3 W h kg –1 at a higher power density of 12640.6 W kg –1 . The value (37.1 W h kg –1 ) for FeCo 2 O 4 NSs//AC ASC is superior than some of reported data for other ASCs such as multiple hierarchical NiCo 2 O 4 //AC (21.4 W h kg –1 at 350 W kg –1 ), Co 3 O 4 coral-like NWs//AC (18.3 W h kg –1 at 750 W kg –1 ), Co 3 O 4 core–shell MSs//AC (16.6 W h kg –1 at 883 W kg –1 ), pod-like MnCo 2 O 4.5 microstructures//AC (19.65 W h kg –1 at 810.64 W kg –1 ), FeCo 2 O 4 @MnO 2 core–shell NSs/CFs//AC (22.68 W h kg –1 at 406.01 W kg –1 ), FeCo 2 O 4 wires/NFs//AC (23 W h kg –1 at 3780 W kg –1 ), FeCo 2 O 4 @MnO 2 core-sheath architecture/NFs//AC (30.55 W h kg –1 at 515.6 W kg –1 ), MgCo 2 O 4 twinned-hemispheres//AC (30.6 W h kg –1 at 861 W kg –1 ), and even some ASCs assembled from the binder-free electrode materials including lily-like Co 3 O 4 /NFs//AC (34 W h kg –1 at 1963 W kg –1 ) and gully network Co 3 O 4 NWs/NFs//AC (33.8 W h kg –1 at 224 W kg –1 ) …”

“…As mentioned above that the voltage window of 0−1.6 V was determined for the tests in the two-electrode system, the CV curves of FeCo 2 O 4 MSs//AC and NSs//AC ASCs at different scan rates of 5, 10, 20, 30, 40, and 50 mV s −1 are 56 Although the FeCo 2 O 4 MSs and FeCo 2 O 4 NSs possess similar values of BET specific surface area, there is a difference in electrochemical performance, which may be related to the difference in their morphology and microstructure. Compared with the three-dimensional (3D) MSs, the 2D NSs with thin thickness can supply sufficient contact between the electrolyte and electrode material and also expose more electrochemically active sites for redox reactions.…”

Co3O4 Nanoparticles Embedded in Mesoporous Carbon for Supercapacitor Applications

“…In general, the presence of two types of pores can lead to an increase of the capacitance of the materials. [ 22,58] The peak identified on the graph by "hydroxide, defects, and C=O" do not give S3, Supporting Information, which varies from 4.70 to 2.96 at. %.…”

Bundlelike CuCo2O4 Microstructures Assembled with Ultrathin Nanosheets As Battery-Type Electrode Materials for High-Performance Hybrid Supercapacitors

“…30 The Co 3 O 4 gully network supported on nickel foam was fabricated by simple hydrothermal reactions and post annealing treatment process, and such Co 3 O 4 achieved both capacity up to 582.8 C g −1 and superior cycling performance. 31 However, the low conductivity of Co 3 O 4 makes its electrochemical property far inferior to the theoretical value. On the other hand, the high cost of cobalt further impedes the practical applications of Co 3 O 4 in supercapacitors.…”

“…prepared the Co 3 O 4 in hierarchical structure with a capacity about 354.6 C g –1 at 0.5 A g –1 (591 F g –1 , −0.2–0.4 V) and 97% capacity retention after 2000 cycles . The Co 3 O 4 gully network supported on nickel foam was fabricated by simple hydrothermal reactions and post annealing treatment process, and such Co 3 O 4 achieved both capacity up to 582.8 C g –1 and superior cycling performance . However, the low conductivity of Co 3 O 4 makes its electrochemical property far inferior to the theoretical value.…”