Uniform porous spinel NiCo2O4 with enhanced electrochemical performances

Mesoporous NiCo2O4 Micro/nanospheres with Hierarchical Structures for Supercapacitors and Methanol Electro–oxidation

“…Compared with the inset of Figure a and Figure b, the inset of Figure c indicates that the mesoporous structure of the NCO with urchin‐like is centered at around 7.7 nm, and the total pore volume is calculated as high as 0.4213 cm 3 ⋅ g −1 , but the BET specific surface area is lower than NCO with nanoflake@ nanoneedle‐like structures. Notably, the as‐resulted pore volume of mesoporous NiCo 2 O 4 3D hierarchical structure is much higher than the reported results, such as NiCo 2 O 4 flakes (0.25 cm 3 ⋅ g −1 ), porous NiCo 2 O 4 nanocomposite (0.286 cm 3 ⋅ g −1 ), NiCo 2 O 4 nanowires (0.22 cm 3 ⋅ g −1 ), NiCo 2 O 4 (SBC) (0.33 cm 3 ⋅ g −1 ), network‐like mesoporous (0.38 cm 3 ⋅ g −1 ) . Such a uniform mesoporous pore structure with a high surface area and large pore volume provide more electroactive sites for methanol electro‐oxidation, and fast transport and diffusion of electrolyte ions during the charge/discharge process, which enhanced the rate capability of supercapacitors.…”

Mesoporous composite nickel cobalt oxide/graphene oxide synthesized via a template-assistant co-precipitation route as electrode material for supercapacitors

“…6f), Rs refers to the internal resistance linked with electronic conductivity of the electrodes, and the ionic conductivity of electrolyte; Rct represents charge transfer resistance through the electrode/electrolyte interface; Zp relates to the Warburg impedance, according to the slope of the line in the low frequency region; Cdl denotes double-layer capacitance of the composite; Clc is the limit capacitance. The Rs and Rct can be estimated from the intercept of the high frequency semicircle with the real axis at Rs and (Rs þ Rct), respectively [45,46]. As shown in Fig.…”

“…Compared with other fabrication methods, including chemical vapor deposition [16], electrodeposition [17], hydrothermal synthesis [2,14], solegel method [18], electrospinning [19], and electrophoretic deposition (EPD) calcination method [20], co-precipitation is a facile, and cost-effective way to prepare binary oxides with short reaction durations [21]. Meanwhile, Supported by the previous reports (shown in Table S1), the as-prepared composite is somehow competitive in electrochemical properties which also delivers a higher specific capacitance than either pure NiCo 2 O 4 particles or graphene oxide.…”

Mixed Nickel Cobalt Manganese Oxide Nanorods for supercapacitor application

“…Different carbon based materials (Zhu et al, 2011;Wang et al, 2009) are very useful for supercapacitor for their high conductivity and surface area. Recent research in supercapacitor materials showed that nanostructured transition metal oxides (Lokhande et al, 2011;Chen et al, 2010;Wu et al, 2015;Ponrouch et al, 2013;Liu and Anderson, 1996;Srinivasan and Weidner, 2000;Lu et al, 2011;Xu et al, 2009;Reddy and Reddy, 2004;Xie et al, 2011) are also attractive material for supercapacitor application because of their high specific surface area, high ionic conductivity and fast redox reactions. These materials show pseudocapacitive effect.…”