Zn-Ni-Co trimetallic carbonate hydroxide nanothorns branched on Cu(OH)2 nanorods array based on Cu foam for high-performance asymmetric supercapacitors

Here we report the development of a high-performance electrode material composed of Zn and Ni co-substituted Co carbonate hydroxide (ZnNi-Co 2 (CO 3 )(OH) 2 ) nanothorns branched on Cu(OH) 2 nanorods array (Cu(OH) 2 @ZnNi-Co 2 (CO 3 )(OH) 2 ), which are grown directly on copper foam current collector. The electrode materials are obtained by a simple in situ oxidation reaction and a hydrothermal strategy. The as-obtained Cu(OH) 2 @ZnNi-Co 2 (CO 3 )(OH) 2 electrode exhibits significantly enhanced electrochemical performance with a high specific capacitance (2746 F g −1 at 1 A g −1 ), and extraordinary cycling stability (maintained 95.61% of the initial capacitance after 6000 cycles at 20 A g −1 ), which are much superior to those of Cu(OH) 2 , Cu(OH) 2 @ Co 2 (CO 3 )(OH) 2 , Cu(OH) 2 @Ni-Co 2 (CO 3 )(OH) 2 , and bare ZnNi-Co 2 (CO 3 )(OH) 2 nanospheres electrodes. Additionally, the Cu(OH) 2 @ZnNi-Co 2 (CO 3 )(OH) 2 nanorods array can also be utilized as the positive electrode to fabricate an asymmetric supercapacitor device with an active carbon negative electrode, realizing a high cell voltage of 1.5 V and the energy density of up to 34.75Wh kg −1 at a power density of 375 W kg −1 . The excellent electrochemical properties can be credited to the three-dimensional hierarchical core-shell architecture. • Hierarchical Cu(OH) 2 @ZnNi-CoCH nanorods array is fabricated on 3D Cu foams. • The materials are obtained by an oxidation reaction and a hydrothermal strategy. • Cu(OH) 2 @ZnNi-CoCH electrode exhibits superb supercapacitive performance.