High performance asymmetric supercapacitor based on vertical nanowire arrays of a novel Ni@Co-Fe LDH core@shell as negative and Ni(OH)2 as positive electrode

Nanotechnology. 2020 Mar 27;31(24):245401. doi: 10.1088/1361-6528/ab7b07. Epub 2020 Feb 28.

Abstract

An efficient synthesis of the electrode material with abundant active sites is imperative for obtaining a flexible supercapacitor with excellent electrochemical performance. Herein, a novel flexible Ni@Co-Fe LDH core-shell nanowires supercapacitor negative electrode is synthesized using polycarbonate membrane on a copper substrate via an electrochemical deposition technique. The synthesized battery-type negative electrode exhibits remarkable specific capacitance of 1289 F g-1 at 1 A g-1 and excellent cycling stability with 76.66% capacitive retention after 5000 cycles. Furthermore, the Ni(OH)2//Ni@Co-Fe LDH nanowires based asymmetric supercapacitor exhibits excellent cycling stability of 90.49% after 1000 cycles with a highest energy density of 68 Wh kg-1 at 0.38 KW kg-1, and a good energy density of 31.8 Wh kg-1 is still attained at a high power density of 6 KW kg-1. For practical demonstration, a white LED of 3.3 V is lit by using two asymmetrical supercapacitor devices connected in series. The device offers a favorable and effective pathway for advanced energy storage.