Hierarchical construction of core–shell metal oxide nanoarrays with ultrahigh areal capacitance

Three-dimensional flower-like Co(OH)2 microspheres of nanoflakes/nanorods assembled on nickel foam as binder-free electrodes for High performance supercapacitors

“…This electrode material exhibited excellent rate capability (71% can be maintained when the current density is increased by 6 times). As shown in Table 1, the ASC of the Co(OH) 2 /Ni foam composite is much higher than those of ordered mesoporous carbon material, directly-grown pseudo-capacitive array nanoarchitectures such as porous Co 3 O 4 nanowire/Ni foam [21], Co 3 O 4 -NiO core-shell nanowire arrays [22], etc. Furthermore, its MSC is comparable to that of nano-Ni/Co(OH) 2 nanoflakes [23].…”

Transition metal oxides/hydroxides nanoarrays for aqueous electrochemical energy storage systems

“…Commonly chemical vapor deposition (CVD) [41] is used for controllable fabrication of highly ordered nanostructure on substrate by gas-solid reaction, while chemical bath deposition and hydrothermal method [42,43] are two typical wet means. Some examples including large area MnO 2 nanowire (70-100 nm in diameter and 1.5 μm in length) arrays grown on fluorine-doped tin oxide coated glass [44], mesoporous (2-5 nm in pore-size) NiCo 2 O 4 nanosheets loading on Ni foam [21], and porous (10-200 nm in diameters) Ni/Co(OH) 2 nanoflake films (20 nm in thickness) by a two-step electrodeposition process on Ni foam [45] have been reported.…”

“…According to the aforementioned advantages of hierarchical structure design, our team has synthesized 3D Co 3 O 4 @Co 3 O 4 and Co 3 O 4 @NiO hierarchical nanoarrays electrodes for SC [42,43,53]. Thanks to the unique architecture, these hierarchical nanoarray electrodes showed excellent electrochemical performance, much better than the individual components (Co 3 O 4 nanosheet arrays and ) and thin morphologies of the electrode result in an ultrahigh areal capacitances up to ~40 F cm −2 , which is the highest among the reported values (Table 1), while the rate capability and cycling stability are well preserved.…”

Hierarchically nanostructured transition metal oxides for supercapacitors

“…12d). Furthermore, Sun et al [181] also fabricated a hierarchical core-shell structure of Co 3 O 4 @NiO nanowire@nanorod arrays via a similar strategy (Fig. 12e).…”