▎ 摘　　要

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.