Self-etching Ni-Co hydroxides@Ni-Cu nanowire arrays with enhancing ultrahigh areal capacitance for flexible thin-film supercapacitors  

作　　者：Peng Guo Yang Shen Yu Song Jing Ma Yuan-Hua Lin Ce-Wen Nan 

机构地区：[1]State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China [2]Laboratory of Advanced Energy Storage Materials and Devices,Research Institute of Tsinghua University in Shenzhen,Shenzhen 518057,China

出　　处：《Rare Metals》2017年第9期691-697,共7页稀有金属（英文版）

基　　金：financially supported by the National Basic Research Program of China(No.2015CB654603);the National Natural Science Foundation of China(No.51572141,51532003);Beijing Nova Program(No.XX2013037);the Research fund of Science and Technology in Shenzhen(No.JSGG20150331155519130)

摘　　要：Flexible thin-film supercapacitors with high specific capacitance are highly desirable for modern wearable or micro-sized electrical and electronic applications. In this contribution, Ni-Co hydroxides（NCH）nanosheets were deposited on top of Ni-Cu alloy（NCA）nanowire arrays forming a freestanding thin-film composite electrode with hierarchical structure for supercapacitors.During electrochemical cycling, the dissolution of Cu into Cu ions will create more active sites on NCA, and the redeposited copper oxide can be coated onto NCH, giving rise to substantial increase in specific capacitance with cycling. Meanwhile, NCA and NCH have excellent conductivity, thus leading to excellent rate performance. This flexible thin-film electrode delivers an ultrahigh initial specific capacitance of 0.63 F·cm^（-2）（or 781.3 F·cm^（-3））.During charge-discharge cycles, the specific capacitance can increase up to 1.18 F·cm^（-2）（or 1475 F·cm^（-3）） along with the“self-etching”process. The electrode presents a better specific capacitance and rate capability compared with previously reported flexible thin-film electrode, and this novel design of etching technique may expand to other binary or ternary materials.Flexible thin-film supercapacitors with high specific capacitance are highly desirable for modern wearable or micro-sized electrical and electronic applications. In this contribution, Ni-Co hydroxides（NCH）nanosheets were deposited on top of Ni-Cu alloy（NCA）nanowire arrays forming a freestanding thin-film composite electrode with hierarchical structure for supercapacitors.During electrochemical cycling, the dissolution of Cu into Cu ions will create more active sites on NCA, and the redeposited copper oxide can be coated onto NCH, giving rise to substantial increase in specific capacitance with cycling. Meanwhile, NCA and NCH have excellent conductivity, thus leading to excellent rate performance. This flexible thin-film electrode delivers an ultrahigh initial specific capacitance of 0.63 F·cm^（-2）（or 781.3 F·cm^（-3））.During charge-discharge cycles, the specific capacitance can increase up to 1.18 F·cm^（-2）（or 1475 F·cm^（-3）） along with the“self-etching”process. The electrode presents a better specific capacitance and rate capability compared with previously reported flexible thin-film electrode, and this novel design of etching technique may expand to other binary or ternary materials.

关 键 词：Nickel Cobalt Copper HYDROXIDES SUPERCAPACITORS 

分 类 号：TB383.2[一般工业技术—材料科学与工程] TM53[电气工程—电器]