Binary metal oxide: advanced energy storage materials in supercapacitors

Abstract

Binary transition metal oxides (BTMOs) possess higher reversible capacity, better structural stability and electronic conductivity, and have been widely studied to be novel electrode materials for supercapacitors.

Facile synthesis of NiMn 2 O 4 nanosheet arrays grown on nickel foam as novel electrode materials for high-performance supercapacitors

“…Among various structures of binary metal oxides, the spinel structured materials have gained ever-growing interests as a result of their excellent physical-chemical properties. Meanwhile, the studies on Mn-based binary metal oxides for supercapacitors have also been reported [3,10]. Padmanathan et al [11] have synthesized nanostructured spinel MnCo 2 O 4 with the specific capacitance of 346 F g -1 at the current density of 1 A g -1 via D-glucose-assisted solvothermal process.…”

Polymer templated nickel cobaltate for energy storage

“…1) provided further proof that the materials were NiCo 2 O 4 and also showed that the Ni and Co are present in multivalent forms consistent with a spinel type structure. The Ni 2p peak was composed of two spin-orbit doublets characteristic of Ni 2+ (855 eV) and Ni 3+ (874 eV) [15,28] while the presence of Co 2+ and Co 3+ was indicated with major signals in the Co 2p peak at the binding energies of 780 eV and 796 eV, respectively [10,29]. The presence of metal-oxygen bonds, consistent with formation of an oxide, was confirmed by a signal at ∼630 cm À1 in the FT-IR spectrum for each material [18,30].…”

“…In developing these new electrode materials researchers have found that enhancing surface area, electrical conductivity, providing short ion-diffusion pathways and having excellent interfacial integrity lead to desirable characteristics for applications ranging from use in electric vehicles to portable electronics [9][10][11][12]. Binary transition metal oxides (BTMOs), as opposed to simple transition metal oxides, can provide all of these characteristics and show particular promise for supercapacitor applications, particularly as they contain mixed metal valencies providing rich redox behaviour for exploitation.…”

Nanostructured spinel manganese cobalt ferrite for high-performance supercapacitors

“…13 In addition, TM oxides can provide a higher theoretical C sp than that of the conventional carbon-based materials and a better electrochemical stability than that of the polymeric materials.…”

“…7 Among them, RuO 2 has been widely investigated as a promising candidate because of its better conductivity and high C sp ; however, it is limited by its high cost, rarity, 13,14 and toxicity. 10 However, few research studies were carried out on ternary TM ferrites as the electrodes for supercapacitor applications as listed in Table 1.…”