Hierarchical NiCo hydroxide nanosheets deposited on 3D porous Ni arrays for cost-effective high-performance supercapacitors

The development of flexible three-dimensional (3D) nanostructured electrodes has been regarded as a promising strategy to fulfill high-performance supercapacitors. Herein, we report a cost-effective method for fabricating flexible supercapacitor electrodes consisting of NiCo-LDH nanosheets electrodeposited on 3D porous Ni arrays/conductive cloth (NiCo-LDH@3D Ni/CC). The hierarchical 3D porous Ni arrays with high conductivity and large specific area not only provide effective interconnected conductive networks, but also enable a high mass loading of active materials. The resultant NiCo-LDH@3D Ni/CC electrode exhibits a high mass capacitance of 2248 F g−1 and a high areal capacitance of 3260 mF cm−2 at 5 mA cm−2. Ultimately, the symmetric solid-state supercapacitor assembled with NiCo-LDH@3D Ni/CC displays a high areal capacitance of 116.7 mF cm−2 at 5 mA cm−2, and excellent cycling stability (full capacitance retention after 10,000 cycles at 10 mA cm−2). This work demonstrates a facile and low-cost strategy for flexible energy storage applications.