Tunable Fabrication of Hollow Nano Sword-Like CuCo₂O₄ Derived from Bimetal–Organic Frameworks as Binder-Free Electrodes

Abstract

This study successfully synthesized highly porous hollow nano sword-like CuCo2O4 with a large specific surface area (80.2 m2 g–1) on a nickel foam substrate through a simple solution-based method followed by a calcination process. Benefiting from their geometrical merits, including excellent structural robustness, large electroactive surface areas, and 3D open structures, the hollow nano sword arrays of CuCo2O4 deliver remarkable electrochemical performances for SCs. Using this binder-free strategy, the synthesized copper cobalt oxide electrode delivers a great specific capacity of 717 C g–1 at 1 A g–1 with an excellent rate capability and cycling stability in a three-electrode cell configuration. Consequently, the fabricated CCO-HS//AC device exhibits the highest specific energy of 54 Wh kg–1 at a specific power of 3137 W kg–1 with a remarkable cycle stability of 91.1% capacity retention after 8000 cycles, indicating its potential as a novel electrode for energy storage systems.

Engineering Rich-Cation Vacancies in CuCo2O4 Hollow Spheres with a Large Surface Area Derived from a Template-Free Approach for Ultrahigh Capacity and High-Energy Density Supercapacitors

“…Additionally, the CCOHS was shown to have a superior capacity compared to numerous previously reported findings regarding CuCo 2 O 4 -based electrode materials (mostly @1 A g –1 ), for instance, CuCo 2 O 4 microspheres (109.4 C g –1 ), CuCo 2 O 4 nanoparticles (229.5 C g –1 @2 A g –1 ), bundle-like CuCo 2 O 4 (303.22 C g –1 ), honeysuckle-like CuCo 2 O 4 /CuO composites (350.69 C g –1 ), flower-like CuCo 2 O 4 (466.4 C g –1 ), chestnut-like CuCo 2 O 4 /NF (502.4 C g –1 ), CuCo 2 S 4 /CuCo 2 O 4 nanoflowers (599.9 C g –1 ), CuCo 2 O 4 @MnMoO 4 core–shell nanosheets (663.8 C g –1 ), and CuCo 2 O 4 /MnCo 2 O 4 //graphene/Ni foam (860.4 C g –1 ) . Also, the CCOHS showed high specific capacity compared with the background of various hollow structured battery-type electrode materials summarized in Table S2 such as hollow nanosword-like CuCo 2 O 4 /NF (717 C g –1 ), NiS hollow microspheres (983.16 C g –1 ), Ni x Co 3– x O 4 hollow particles (597.96 C g –1 ), and NiCo 2 Se 4 (943.2 C g –1 ) . The CCOHS electrode also demonstrated 92% initial capacity retention with a current density increase of 10 times and 82% initial capacity retention with a current density increase of 20 times.…”

“…26 Additionally, the CCOHS was shown to have a superior capacity compared to numerous previously reported findings regarding CuCo 2 O 4 -based electrode materials (mostly @1 A g −1 ), for instance, CuCo . 22 Also, the CCOHS showed high specific capacity compared with the background of various hollow structured battery-type electrode materials summarized in Table S2 such as hollow nanosword-like CuCo 2 O 4 /NF (717 C g −1 ), 19 NiS hollow microspheres (983.16 C g −1 ), 53 Ni x Co 3−x O 4 hollow particles (597.96 C g −1 ), 54 and NiCo 2 Se 4 (943.2 C g −1 ). 55 The CCOHS electrode also demonstrated 92% initial capacity retention with a current density increase of 10 times and 82% initial capacity retention with a current density increase of 20 times.…”

“…Copper cobaltite (CuCo 2 O 4 ; CCO) has received much interest as a viable electrode material for SCs and Li-ion batteries and an electrocatalyst for oxygen evolution reactions among the various spinels. , This is due to the low cost of cobalt and copper species, nontoxicity, and synergistic effects between the two metal cations as highly electrochemically active and conductive species . Various CCO nano-/microstructures with different electrochemical characteristics have been reported in SCs .…”

Highly Flexible PEDOT Film Assembled with Solution-Processed Nanowires for High-Rate and Long-Life Solid-State Supercapacitors

“…Such unusual high-rate performance is more obvious by plotting the current response at 0.3 V (vs Ag/AgCl) with the scan rate (Figure S4), where the current response increases nearly linearly with the scan rates of up to 1.0 V s –1 . According to the formula i = av b , , the b value of 0.96 and 0.95 has been obtained for the charging and discharging processes, respectively, by fitting the plots of log ( i ) vs log ( v ) over a wide scan rate range of 10–1000 mV s –1 (Figure c). It should be mentioned that the b values for the PEDOT-6h film nearly approach 1, indicative of the purely capacitive electrochemical behavior for carbon electrodes.…”

Binder‐Free MOF‐Based and MOF‐Derived Nanoarrays for Flexible Electrochemical Energy Storage: Progress and Perspectives

“…Direct pyrolysis of selected MOFs to obtain metal oxide arrays has been widely reported. [112,[137][138][139][140] For example, Zheng et al reported a facile and scalable route for the in situ fabrication of ultrafine MnO nanocrystals embedded in porous carbon matrix (MnO@C), which was used as anodes for lithium-ion batteries, exhibiting a high reversible specific capacity of 1221 mAh g −1 after 100 cycles at a current density of 100 mA g −1 . [114] Tan et al also prepared a Mn-MOF derived Mn 3 O 4 with bulk oxygen defects (O d -Mn 3 O 4 @C) through valence engineering, which was used as a cathode material for aqueous Zn ion battery with ultralong cycle life.…”