3D porous gear-like copper oxide and their high electrochemical performance as supercapacitors

Abstract

A facile and mild approach was used for the controlled synthesis of 3D porous gear-like CuO on a Cu substrate (PGC) based on annealing gear-like Cu(OH) 2 (GC) at 200 uC in air. There are 3-10 edges that build up a gear-like structure and a huge number of holes formed on each edge. As an integrated nanostructure, the binder-free PGC can be used as a supercapacitors electrode (SC) directly. Due to its 3D porous structure and the highly conductive Cu substrate as a current collector, the integrated electrode exhibited excellent electrochemical properties. These were demonstrated by excellent specific capacitance as high as 348 F g 21 at a discharge current density of 1 A g 21 , which corresponds to the energy density of 43.5 Wh kg 21 . The electrochemical tests also showed that the as-synthesized PGC exhibited excellent cycling stability.

Facile synthesis of Cu2O/CuO/RGO nanocomposite and its superior cyclability in supercapacitor

“…Introducing another metal or metal oxide is also a favorite route [20][21][22][23][24][25][26][27]. Based on these processes, CuO-based pseudocapacitor has enhanced specific capacitance and high rate capability [9,11,14,17,26]. Apart from capacitance, the other preliminary requirement for a high quality pseudocapacitor material is its cyclic stability, especial long-term cyclability.…”

“…Integrating CuO with carbon materials, including porous carbon [3], carbon nanotube [4][5], and graphene [6][7], has proved to be an efficient method. Controlling the shape, morphology, and structure of CuO is also a good solution [1][2][8][9][10][11][12][13][14][15][16][17][18][19]. Introducing another metal or metal oxide is also a favorite route [20][21][22][23][24][25][26][27].…”

Characterisation and electrochemical behaviour of electrodeposited Cu–Fe foams applied as pseudocapacitor electrodes

“…Copper oxide films also exhibit modest specific capacitances that may vary between 6 Fg -1 to 43 Fg -1 [8,9]. However, specific capacitance as high as 348 F g -1 has been reported that Cu oxides with 3D porous structures [10]. High surface area/ porosity are therefore key features to optimize the specific capacitance of these materials.…”

“…The enhanced electrochemical response of Cu-Fe foams deposited at 1.5 Acm -2 for 90 s can be related to their chemical composition and morphology. When compared to samples deposited for 180 s, they present a higher Fe content(Figure 4) which favour a higher capacitance due to the generally higher capacitance of Fe oxides when compared to copper oxides[5][6][7][8][9][10]. Furthermore, Cu-Fe foams deposited at 90 s also have a lower deposited mass that results in a less developed network morphology than foams deposited at 180 s (…”

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

“…The nucleation process on the surface of substrate is quite slow, which avoids the mixed and disorderly arrangement. The hydrothermal method has many advantages: i) this route is very versatile because the hydrothermal process occurs on a variety of materials, such as Ni(OH) 2 [46], MnO 2 [47], Co(OH) 2 [22,48], FeOOH [49], Cu(OH) 2 [50], ZnO [51], V 2 O 5 [52]; ii) the reaction parameters can be easily controlled including temperature, time and concentration, which would result in different morphologies, porosity and compositions of the final products [19,53] [58]), which offer an even higher porosity and mass-loading of the active layer.…”