High‐Stacking‐Density, Superior‐Roughness LDH Bridged with Vertically Aligned Graphene for High‐Performance Asymmetric Supercapacitors. Issue 37 (8th August 2017)

• Record Type: Journal Article
• Authors: Guo, Wei; Yu, Chang; Li, Shaofeng; Yang, Juan; Liu, Zhibin; Zhao, Changtai; Huang, Huawei; Zhang, Mengdi; Han, Xiaotong; Niu, Yingying; Qiu, Jieshan
• Is Part Of: Small. Volume 13:Issue 37(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-08-08
• Subjects: stacking density -- supercapacitors -- vertically aligned graphene -- wettability; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201701288
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract : The high‐performance electrode materials with tuned surface and interface structure and functionalities are highly demanded for advanced supercapacitors. A novel strategy is presented to conFigure high‐stacking‐density, superior‐roughness nickel manganese layered double hydroxide (LDH) bridged by vertically aligned graphene (VG) with nickel foam (NF) as the conductive collector, yielding the LDH‐NF@VG hybrids for asymmetric supercapacitors. The VG nanosheets provide numerous electron transfer channels for quick redox reactions, and well‐developed open structure for fast mass transport. Moreover, the high‐stacking‐density LDH grown and assembled on VG nanosheets result in a superior hydrophilicity derived from the tuned nano/microstructures, especially microroughness. Such a high stacking density with abundant active sites and superior wettability can be easily accessed by aqueous electrolytes. Benefitting from the above features, the LDH‐NF@VG can deliver a high capacitance of 2920 F g −1 at a current density of 2 A g −1, and the asymmetric supercapacitor with the LDH‐NF@VG as positive electrode and activated carbon as negative electrode can deliver a high energy density of 56.8 Wh kg −1 at a power density of 260 W kg −1, with a high specific capacitance retention rate of 87% even after 10 000 cycles. Abstract : High‐stacking‐density, superior‐roughness integrated architectures made of layered double hydroxide (LDH) bridged with vertically aligned graphene (VG) are configured, indicative of a superior hydrophilic behavior derived from controllable nano/microstructures. As such, an asymmetric supercapacitor made up of LDH‐nickel foam@VG and activated carbon delivers high energy density and excellent cycling retention rate.