Enhancing the Kinetic Process in Biphasic Crystalline NiWO₄/Amorphous Co‐B Electrode Materials toward Energy Storage with Ultrahigh Rate Performance

Abstract

Here, we report a two‐phase crystalline NiWO4/amorphous Co−B nanocomposite as an electrode material for supercapacitors, which is effectively synthesized via a simple hydrothermal method and chemical precipitation method. The obtained NiWO4/Co−B exhibits crystal‐amorphous contact, which makes it have more active sites than other crystalline‐crystalline phase boundaries, thereby enhancing electron transport. The NiWO4/Co−B electrode with the best mass ratio of crystalline and amorphous exhibits a great specific capacitance and excellent cycle durability. Compared to individual Co−B and NiWO4, it also shows enhanced rate capability Besides, NiWO4/Co−B/activated carbon supercapacitor device can provide a good specific capacitance and a maximum energy density of 10.92 Wh kg−1 at 200 W kg−1. This work provides new insights to develop novel electrode materials for energy storage and conversion.

Research Advances in Amorphous‐Crystalline Heterostructures Toward Efficient Electrochemical Applications

“…Heterogeneous nanomaterials that have uncommon microstructures generally display large surface area, high surface/volume ratios, and abundant ion-accessible active sites, being one kind of promising electrode candidate for advanced supercapacitors. [164][165] Specifically, the heterogeneous structures with amorphous-crystalline hetero-phases have exhibited glamorous capability to promote the carrier's transportation at the unique heterointerfaces for considerably enhancing the supercapacitor performance, [95,108,115,[166][167][168] such as the proposed Ni/V-doped Co 3 S 2 @Co/Ni-doped VS 2 heterostructures, [113] NiCoMoS@NiCoAl hydrotalcite, [169] Ni 3 V 2 O 8 @Co-B nanocomposites [170] and so on. Zhou et al designed the amorphous Ni-Co-S/crystalline MnS heterostructure confined onto the interior wall and exterior surfaces of tripleshelled hollow nanostructure (denoted as NCM-S@HCNS) for supercapacitor, which displays an unexpected specific capacity as high as 1093 C g −1 at 1 A g −1 and excellent retention ration of 90.4% after 5000 cycles at 10 A g −1 .…”

“…Heterogeneous nanomaterials that have uncommon microstructures generally display large surface area, high surface/volume ratios, and abundant ion‐accessible active sites, being one kind of promising electrode candidate for advanced supercapacitors. [ 164–165 ] Specifically, the heterogeneous structures with amorphous‐crystalline hetero‐phases have exhibited glamorous capability to promote the carrier's transportation at the unique heterointerfaces for considerably enhancing the supercapacitor performance, [ 95,108,115,166–168 ] such as the proposed Ni/V‐doped Co 3 S 2 @Co/Ni‐doped VS 2 heterostructures, [ 113 ] NiCoMoS@NiCoAl hydrotalcite, [ 169 ] Ni 3 V 2 O 8 @Co‐B nanocomposites [ 170 ] and so on. Zhou et al.…”