Flower-like Y-doped α-Ni(OH)2/graphene heterostructure as advanced electrodes for high performance supercapacitor. (February 2020) - Zhu, Yuanyi
Abstract: To achieve high electrochemical performance, Ni hydroxide electrode materials need enhancing its intrinsic poor conductivity and fully utilizing their electroactive sites. Herein, we fabricate yttrium (Y) doped Ni(OH)2 /graphene nanosheets heterostructure (Y-Ni/GNS) via a solvothermal method. The flower-like Y-Ni/GNS microspheres consist of numerous wrinkled nanoflakes and transparent graphene nanosheets, which provide increased surface areas, excellent electrical conductivity and abundant reaction sites. The Y-Ni/GNS heterostructure exhibits a remarkable specific capacity of 822.3 C g −1 at 1 A g −1, and ultrahigh rate performance (562.4 C g −1 at 20 A g −1 ). The as-fabricated Y-Ni/GNS//AC device delivers an energy density of 81.6 Wh kg −1 at 1129.8 W kg −1 and ultra-long cycling life, with 83.28% retention after 7000 cycles. Highlights: The flower-like Y-Ni/GNS heterostructure is facilely prepared. The Y-Ni/GNS heterostructure exhibited excellent conductivity and high-efficient charge storage. The Y-Ni/GNS//AC device delivered an energy density of 81.6 Wh kg −1 at 1129.8 W kg −1 .