NiCo layered double hydroxide nanocages for high-performance asymmetric supercapacitors

Herein, well-designed NiCo layered double hydroxide (NiCo-LDH) nanocages are prepared by a simple Cu2O template etching method. Due to their unique hollow structures and synergistic effects, NiCo-LDH-1 (molar ratio of Ni and Co is 1 : 1) nanocages exhibit superior capacitance (1671 F g(-1)@1 A g(-1)) in a three-electrode system. In addition, a supercapacitor device is prepared with NiCo-LDH-1 nanocages as the cathode and active carbon (AC) as the anode which shows a maximum energy density of 59.0 W h kg(-1)@935.7 W kg(-1) power density and displays high cycling stability with a capacitance retention rate of 87.1% after 10 000 cycles at 10 A g(-1). A light emitting diode was powered by the assembled supercapacitor and remained illuminated for similar to 12 min. In order to understand the charge storage mechanism of supercapacitors during the electrochemical charge/discharge process, the structure of NiCo-LDH-1 was studied in detail by in situ X-Ray Diffraction (XRD).

Automated summary

Well-designed NiCo layered double hydroxide (NiCo-LDH) nanocages were prepared by a Cu2O template etching method, exhibiting superior capacitance and high cycling stability. A supercapacitor device was constructed using NiCo-LDH-1 nanocages as the cathode and active carbon (AC) as the anode, achieving a high energy density and power density. The charge storage mechanism of the supercapacitors during the electrochemical process was studied using in situ X-Ray Diffraction (XRD).