title: Nickel Cobalt Hydroxide @Reduced Graphene Oxide Hybrid Nanolayers for High Performance Asymmetric Supercapacitors with Remarkable Cycling Stability.
abstract: Nanolayered structures present significantly enhanced electrochemical performance by facilitating the surface-dependent electrochemical reaction processes for supercapacitors, which, however, causes capacitance fade upon cycling due to their poor chemical stability. In this work, we report a simple and effective approach to develop a stable, high performance electrode material by integrating 2D transition metal hydroxide and reduced graphene oxide sheets at nanometer scale. Specifically, a hybrid nanolayer of Ni-Co hydroxide @reduced graphene oxide (Ni,Co-OH/rGO) with an average thickness of 1.37 nm is synthesized through an easy one-pot hydrothermal method. Benefiting from the face to face contact model between Ni-Co hydroxide and rGO sheets, such unique structure presents superior specific capacitance and cycling performance as compared to the pure Ni-Co hydroxide nanolayers. An asymmetric supercapacitor based on Ni,Co-OH/rGO and three-dimensional (3D) hierarchical porous carbon is developed, exhibiting a high energy density of 56.1 Wh kg(-1) along with remarkable cycling stability (80% retention after 17 000 cycles), which holds great promise for practical applications in energy storage devices.
authors.affiliation: Key Laboratory of Applied Chemistry, Yanshan University , Qinhuangdao 066004, China.
authors.forename: Hongnan
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory of Applied Chemistry, Yanshan University , Qinhuangdao 066004, China.
authors.forename: Jing
authors.initials: J
authors.lastname: He
authors.affiliation: State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , Shanghai 200240, China.
authors.forename: Ding-Bang
authors.initials: DB
authors.lastname: Xiong
authors.affiliation: Department of Materials Science and Engineering, EPIC, NUANCE Center, Northwestern University , 2220 Campus Drive, Evanston, Illinois 60208, United States.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Materials Science and Engineering, EPIC, NUANCE Center, Northwestern University , 2220 Campus Drive, Evanston, Illinois 60208, United States.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, EPIC, NUANCE Center, Northwestern University , 2220 Campus Drive, Evanston, Illinois 60208, United States.
authors.forename: Vinayak
authors.initials: V
authors.lastname: Dravid
authors.affiliation: Key Laboratory of Applied Chemistry, Yanshan University , Qinhuangdao 066004, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhao
keywords: Ni−Co hydroxide; cycling stability; nanolayer; supercapacitor; ultrathin