Direct growth of mesoporous MnO 2 nanosheet arrays on nickel foam current collectors for high-performance pseudocapacitors

High-performance α-MnO2 nanowire electrode for supercapacitors

“…Even at a current density as high as 32 A g À1 , it still retained a high SC of 112 F g À1 . This result is much better than those reported in previous work such as 3-D porous coral-like MnO 2 thinfilm [39] (96 F g À1 at a current density of 20 A g À1 ), mesoporous MnO 2 nanosheet arrays [40] (96 F g À1 at a current density of 20 A g À1 ) and mesoporous MnO 2 nanowire array [31] (84 F g À1 at a current density of 12 A g À1 ).…”

“…This can be explained by the fact that in the high frequency region, only a limited part of electrode surface is utilized as a capacitor due to the reduced penetration depth of the AC voltage with increasing frequency, and the capacitance turns to be smaller and smaller when the frequency is going up. Hence, the superior capacitance response at high frequency region suggests a better utilization of active electrode materials [40]. It can be seen from Fig.…”

“…7(b). It can be seen that the SC decreases with increasing frequency, which is a common phenomenon for a porous electrode [40,50]. This can be explained by the fact that in the high frequency region, only a limited part of electrode surface is utilized as a capacitor due to the reduced penetration depth of the AC voltage with increasing frequency, and the capacitance turns to be smaller and smaller when the frequency is going up.…”

One pot low-temperature growth of hierarchical δ-MnO2 nanosheets on nickel foam for supercapacitor applications

“…By a closer examination of the MnNF-30 electrode in Fig. 2f, it is found that numerous d-MnO 2 nanosheets are interconnected laterally, forming a highly open and porous structure [21], which is favorable for the electron transportation among the materials and improve their capacitive performances.…”

H–TiO2/C/MnO2 nanocomposite materials for high-performance supercapacitors

“…Among the transition metal oxides, MnO 2 has attracted much attention for its high theoretical specific capacitance, low cost, and environmental friendliness (Kundu and Liu 2013;Mai et al 2013a). However, the practical capacitance of MnO 2 materials is far lower than their theoretical specific capacitance because of their intrinsically poor electronic conductivity and densely packed structure (Toupin et al 2004).…”