Facile construction of Co(OH)2@Ni(OH)2 core-shell nanosheets on nickel foam as three dimensional free-standing electrode for supercapacitors. (10th January 2019) - Wang, You
Abstract: Fabricating three dimensional (3D) free-standing electrode is considerable attractive in designing supercapacitors of high energy and power densities. Co(OH)2 @Ni(OH)2 core-shell nanosheets have been successfully grown on nickel foam (NF) as 3D free-standing electrode (denoted as NCN) for electrochemical capacitors via a facile stepwise electrodeposition process. It is found that the unique 3D free-standing frameworks combined with the core-shell nanosheet-like heterostructure endow the as-prepared electrode good electrochemical performances. When tested as a supercapacitor electrode, it delivers a capacitance of 1520.6 F g −1 at 1 A g −1 and still keeps 1376.6 F g −1 at 10 A g −1, exhibiting excellent rate performance. Moreover, it retains ∼71.4% initial capacitance after 1500 charging/discharging cycles at 5 A g −1, demonstrating good cycling stability. The good electrochemical performance of the NCN electrode makes it a promising electrode candidate for high performance supercapacitors. Graphical abstract: In this work, we demonstrate a simple and highly controlled two-step electrodeposition method for construction of cobalt hydroxide @nickel hydroxide core-shell heterostructure that are directly grown on conductive substrates, which shows better electrochemical performance than its single component counterparts. Image 1 Highlights: Co(OH)2 @Ni(OH)2 core-shell heterostructured nanosheets are grown on nickel foam by two-step electrodeposition method. The introduction of Co(OH)2 interlayer enhances the integrity of the whole electrode. This heterostructured electrode shows better electrochemical performances than its single counterparts. The good electrochemical performance could be ascribed to the unique electrode configuration.