Rationally Designed Three-Dimensional NiMoO₄/Polypyrrole Core–Shell Nanostructures for High-Performance Supercapacitors

Abstract

Electrodes of rationally designed composite nanostructures can o®er many opportunities for the enhanced performance in electrochemical energy storage. This paper attempts to illustrate the design and production of NiMoO 4 /polypyrrole core-shell nanostructures on nickel foam to be used in supercapacitor via a facile hydrothermal and electrodeposition process. It has been veri¯ed that this novel nanoscale morphology has outstanding capacitive performances. While employed as electrodes in supercapacitors, the composite nanostructures showed remarkable electrochemical performances with a great areal capacitance (3.2 F/cm 2 at a current density of 5 mA/cm 2 ), and a signi¯cant cycle stability (80% capacitance retention after 1000 cycles). The above results reveal that the composite nanostructures may be a likely electrode material for high-performance electrochemical capacitors.

Recent developments and future perspectives on energy storage and conversion applications of nickel molybdates

“…Hydrothermal synthesis covers the largest share of exertions witnessed for the preparation and modulation of properties of NiMoO 4 28,32,54,63,65,69,74,75,77,78,123,161,165,166,168,170‐173,179,183,184,187,192‐194,198,200,202,206,210‐212,214,215,229,231‐234,256,258‐263,265‐268,270,271,273,275,279‐281,284,286‐288,290,291,294‐298,301,303,305‐313,315‐319,322,324,327‐331,333‐335,337,339‐347,349,352,353,356,358‐360,363‐366,368,370‐374,376‐380 . Typically, it includes a host of strategies towards crystallizing substances from high‐temperature watery mixtures at high vapor pressures.…”

“…All colloidal particles that can be utilized to form stable suspensions and that can convey a charge which can be used for electrodeposition. Mostly, NiMoO 4 particles synthesized by other means are electrodeposited on nickel foam or similar substrates to form an electrode for electrocatalytic reaction 121,172,177,265,272,340,354 . Figure 21B is for schematic explanation of electrodeposition process 177 .…”

“…This is so because this strategy offers the most convenient processes and yet conducive outcomes. Table 6 is to impart a brief account of a host of developments in catalytic properties of NiMoO 4 done involving heterostructures and hybrids 121,123,256‐382 . in many cases, doping, defect and/or morphology engineering have been amalgamated with the heterostructure for superior enhancement in catalytic properties either to generate more surface area or more population of active sites or for other special necessities as summarized in Table 6.…”

“…NiMoO 4 , while hybridized with conducting polymer, becomes a matter of particular interest due to better control in defect site and crystallinity of the binary oxide layer resulting in better redox performance, especially in cases where light weight is of paramount importance 415 There are many instances where such a strategy is proven helpful in reporting better performance as supercapacitor. A few such results have been compared in Table 9 228,233,272,274,340,345,353 …”

Sophisticated Structural Tuning of NiMoO4@MnCo2O4 Nanomaterials for High Performance Hybrid Capacitors

“…The composite electrodes constructed from these two materials can effectively improve the conductivity, specific surface area, and number of reaction sites, thereby improving the overall electrochemical performance. [ 26 , 27 , 28 ].…”