Ternary nanostructured MZnCo oxides (M=Al, Mg, Cu, Fe, Ni) prepared by hydrothermal method as excellent charge storage devices

Recent progress in ZnCo2O4and its composites for energy storage and conversion: a review

“…Therefore, the challenge to fabricate highly efficient binder-free electrode materials capable of storing rapidly larger amounts of energy, at low cost, can be achieved by using ZnCo2O4modified electrodes. Hence, binder-free electrodes based on pristine ZnCo2O4 nanorods 78,79 , nanobelts 80 , nanoribbons 81 , nanoflowers 82 , nanoflakes 83,84 , nanosheets [85][86][87][88][89] , nanomuscles 90 , nanowires 65,91 , nanoleaves 92 , nanocubes 93 , micro-urchins 94,95 , nanoneedles 89 were also reviewed for supercapacitor applications (Table 2) and will be discussed along with slurry-casted electrodes according to their morphology. 19…”

“…This can partially buffer the strain effect through the charge-discharge processes, improve the specific surface area and active sites availability, and lower the interior resistance, facilitating electron transfer and resulting in such high specific capacitance. Aside from 3D ZnCo2O4 NPs, the literature have reported a series of 2D-structured ZnCo2O4, such as micro- 60 and nanosheets [70][71][72][73][85][86][87][88][89] , nanoplates 56 , nanoflakes 83,84 , nanoleaves 92 , nanobelts 80 , nanoribbons 81 , and those based on radial growth of nanosheets, i.e., micro- 65,66 and nanoflowers 74,82 . In addition, there are 1D-structured ZnCo2O4, such as urchin-like microspheres 64 , nanorods 75,78,79 and nanotubes 77 .…”

“…When assembled in binder-free electrodes on the other hand, sheet-like ZnCo2O4 materials present superb specific capacitance, rate capability and cycling stability and are quite competitive 80,81,[83][84][85][86][87][88][89]92 . Nanosheets are the most studied 2D morphology of ZnCo2O4 [85][86][87][88] , featuring porous nanosheets networks on NF (3.19 F cm -2 at 2 mA cm -2 ) 86 , intertwined nanosheet arrays on CC (1750 F g -1 at 1.5 A g -1 ) 87 and NF (400 F g -1 at 1 A g -1 ) 88 , ultra-thin curved nanosheet arrays on NF (1848.9 F g -1 at 5 A g -1 ) 85 (Figure 4B).…”

“…Other binder-free electrodes based on 2D ZnCo2O4 materials were also produced in recent years, i.e. nanobelts (1197.14 F g -1 at 2 A g -1 ) 80 nanoribbons (1957.7 F g -1 at 3 mA cm -2 ) 81 , flake-like nanostructures (~ 41 mAh g -1 at 2 A cm -2 ) 83 , nanoflakes (1170 F g -1 at 2 A g -1 ) 84 , nanoleaves (1700 F g -1 at 1 A g -1 ) 92 , and porous Al0.5Zn0.5Co2O4 nanosheet arrays on NF (~ 1200 F g -1 at 20 A g -1 ) 89 .…”

“…The ZnCo2O4 nanobelts-decorated CC 80 had similar structure to interconnected nanosheets and thus provide performance to ZnCo2O4 nanosheets materials [85][86][87][88] , while flakelike ZnCo2O4 nanostructures on CC 83 , leaf-like ZnCo2O4 nanostructures on NF 92 and Al0.5Zn0.5Co2O4 nanosheet arrays on NF 89 presented poor rate capabilities despite their high cycling stabilities. The trimetallic oxide-based electrode of porous delivered slightly better performance than pristine ZnCo2O4 micro-urchin arrays on NF produced in the same work (approximately 1000 F g -1 at 20 A g -1 ) due to the incorporation of a third metallic center that can enhance even further the ZnCo2O4 electrochemical behavior.…”