Highly Uniform MnCo₂O₄ Hollow Spheres‐Based All‐Solid‐State Asymmetric Micro‐Supercapacitor via a Simple Metal‐Glycerate Precursor Approach

Abstract

Developing a high‐energy‐density all‐solid‐state asymmetric micro‐supercapacitor (AMSC) still remains a big challenge. Herein, a simple metal‐glycerate precursor strategy is used for the synthesis of highly uniform MnCo2O4 hollow spheres, and the all‐solid‐state AMSC is fabricated by MnCo2O4 hollow spheres. It is found that the MnCo2O4 hollow sphere electrode processes a high specific capacitance (0.80 F cm−2) at 2 mA cm−2 and an excellent cycling stability (99% capacitance retention after 2000 cycles). The as‐fabricated all‐solid‐state AMSC displays a high energy density of 0.052 mWh cm−3, a high power density of 320 mW cm−3, and a long cycling life (95.7% capacitance retention after 10 000 charge/discharge cycles). In addition, the all‐solid‐state AMSC can be easily assembled in series to achieve a desirable output voltage, which can drive a light‐emitting diode. This work demonstrates that the MnCo2O4 hollow spheres can be a promising electrode material for a stable, high‐energy‐density micro‐supercapacitor (MSC).

Multifunctional spinel MnCo2O4 based materials for energy storage and conversion: a review on emerging trends, recent developments and future perspectives

“…In addition, it is important for a supercapacitor to have suitable fitting pore size distribution and large specific surface area, aiming to decrease the consumption of electrolyte by regulating the porous structure and morphology of the electrode, which determine the ion diffusion and conductivity, thereby affecting the capacitance of the supercapacitor. MnCo 2 O 4 materials with different morphologies, such as spheres, 36 granules, 37 cuboidal microcrystals, 27 nanoneedles, 38 nanorods, 39,40 cubes, 26,41 nanosheets, 42–44 nanocages, 45 tunable porous structures, 46 hollow spheres, 47 and network-like porous structures, 48,49 can be prepared and tested for their usefulness as supercapacitor electrodes. For example, 1D MnCo 2 O 4 nanowire arrays showed a specific capacitance of 349.8 F g −1 at 1 A g −1 and an energy density of 35.4 W h kg −1 at a power density of 225 W kg −1 .…”

Multifunctional coatings of exfoliated and reassembled graphite on cellulosic substrates

“…Components Capacitance mF cm -2 Ni3V2O8@PANI 30 585 Annealed carbon cloth 31 2,900 Ni(OH)2/C/Cu // Mn3O4/C/Cu 32 216 ERG on paper (this work) 350 Activated carbon (AC) on polyimide film 33 35 Graphene/AC on polyimide film 19 37 Graphene on polyimide film 19 8 MnCo2O4 hollow spheres on carbon fibres 34 800 P3MT/HACNT on PDMS 35 3,100 HACNT on PDMS 21 750 Buckypaper on PDMS 21 250 Graphene-graphite/PU 36 16 Please do not adjust margins Please do not adjust margins For instance, any square coating with this resistance dissipates 1.3 watt only, under a 15 A current. If the voltage fed to the circuit is 120 V, the power dissipated in the coating square is less than 0.1%.…”

Engineering stable construction of MnCo2O4 yolk-in-double-shell amalgamated with bio-synthesized ZnMn2O4 nanoparticles for superior artificial CO2 reduction

“…12,13 However, this innovative approach is still associated with challenges given that the preparation of multi-shelled hollow spheres (MSHSs) requires a harsh ramping heating rate during the calcination of metals-alkoxide, leading to the collapse of their structure. 8,14,15 Herein, we engineered the part of MSHS formation via the solvothermal process of metal-alkoxide, enabling yolk-in-double-shelled hollow spheres of MnCo 2 O 4 (YDSHS-MCO) to be fabricated through the two sequential yolkshells formation, i.e., one by the solvothermal process to achieve yolk-shelled metal-alkoxide and the other by the calcination process to convert the yolk of metal-alkoxide to another yolkshelled structure. Based on this superior approach, the metalalkoxide was subjected to calcination at a moderate heating rate, thereby introducing highly organized, uniform YDSHS.…”