title: Assembling carbon quantum dots to a layered carbon for high-density supercapacitor electrodes.
abstract: It is found that carbon quantum dots (CQDs) self-assemble to a layer structure at ice crystals-water interface with freeze- drying. Such layers interconnect with each other, forming a free-standing CQD assembly, which has an interlayer distance of about 0.366 nm, due to the existence of curved carbon rings other than hexagons in the assembly. CQDs are fabricated by rupturing C60 by KOH activation with a production yield of ~15 wt.%. The CQDs obtained have an average height of 1.14 nm and an average lateral size of 7.48 nm, and are highly soluble in water. By packaging annealed CQD assembly to high density (1.23 g cm(-3)) electrodes in supercapacitors, a high volumetric capacitance of 157.4 F cm(-3) and a high areal capacitance of 0.66 F cm(-2) (normalized to the loading area of electrodes) are demonstrated in 6 M KOH aqueous electrolyte with a good rate capability.
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Guanxiong
authors.initials: G
authors.lastname: Chen
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Shuilin
authors.initials: S
authors.lastname: Wu
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Liwei
authors.initials: L
authors.lastname: Hui
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Jianglin
authors.initials: J
authors.lastname: Ye
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Ziqi
authors.initials: Z
authors.lastname: Tan
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Wencong
authors.initials: W
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Zhuchen
authors.initials: Z
authors.lastname: Tao
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Yang
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.|iChEM, University of Science and Technology of China, 96 Jin Zhai Rd, Hefei, Anhui, 230026, P.R. China.
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Zhu