NiSe2/Ni(OH)2 Heterojunction Composite through Epitaxial-like Strategy as High-Rate Battery-Type Electrode Material
Hao Mei, Zhaodi Huang, Ben Xu, Zhenyu Xiao, Yingjie Mei, Haobing Zhang, Shiyu Zhang, Dacheng Li, Wenpei Kang, Dao Feng Sun
Abstract
Abstract Constructing heterojunction is a promising way to improve the charge transfer efficiency and can thus promote the electrochemical properties. Herein, a facile and effective epitaxial-like growth strategy is applied to NiSe 2 nano-octahedra to fabricate the NiSe 2 -(100)/Ni(OH) 2 -(110) heterojunction. The heterojunction composite and Ni(OH) 2 (performing high electrochemical activity) is ideal high-rate battery-type supercapacitor electrode. The NiSe 2 /Ni(OH) 2 electrode exhibits a high specific capacity of 909 C g −1 at 1 A g −1 and 597 C g −1 at 20 A g −1 . The assembled asymmetric supercapacitor composed of the NiSe 2 /Ni(OH) 2 cathode and p-phenylenediamine-functional reduced graphene oxide anode achieves an ultrahigh specific capacity of 303 C g −1 at 1 A g −1 and a superior energy density of 76.1 Wh kg −1 at 906 W kg −1 , as well as an outstanding cycling stability of 82% retention for 8000 cycles at 10 A g −1 . To the best of our knowledge, this is the first example of NiSe 2 /Ni(OH) 2 heterojunction exhibiting such remarkable supercapacitor performance. This work not only provides a promising candidate for next-generation energy storage device but also offers a possible universal strategy to fabricate metal selenides/metal hydroxides heterojunctions.