A novel Ni@Ni(OH)2 coaxial core-sheath nanowire membrane for electrochemical energy storage electrodes with high volumetric capacity and excellent rate capability

Abstract

We report a facile approach to fabricate a novel membrane electrode based on unique Ni@Ni(OH)2 coaxial core-sheath structures for electrochemical energy storage application in this work. The Ni nanowire membranes, prepared from vacuum filtration of Ni nanowires with unique embossments, can be used as excellent precursors for preparing Ni@Ni(OH)2 membranes by an electrochemical cyclic voltammetry method. After electrochemical treatment, a layer of amorphous Ni(OH)2 was obtained on the surface of Ni nanowires. An important property of the as-synthesized Ni@Ni(OH)2 membranes is that it can be directly utilized for electrochemical energy storage applications without the need for binders or additional conducting additives. The Ni@Ni(OH)2 electrode demonstrates a high volumetric capacity (111.1Ccm−3 at 0.12Acm−3), excellent rate capability (83.1Ccm−3 at 1.92Acm−3), and cycling stability at a high current density (78% capacity retention after 1500 cycles at 1.92Acm−3). This fabrication method is very simple and paves a new route for designing membrane electrodes based on similar structures for high-performance electrochemical energy storage electrodes.