2D Metal–Organic Frameworks Derived Nanocarbon Arrays for Substrate Enhancement in Flexible Supercapacitors

Abstract

Direct assembling of active materials on carbon cloth (CC) is a promising way to achieve flexible electrodes for energy storage. However, the overall surface area and electrical conductivity of such electrodes are usually limited. Herein, 2D metal-organic framework derived nanocarbon nanowall (MOFC) arrays are successfully developed on carbon cloth by a facile solution + carbonization process. Upon growth of the MOFC arrays, the sites for growth of the active materials are greatly increased, and the equivalent series resistance is decreased, which contribute to the enhancement of the bare CC substrate. After decorating ultrathin flakes of MnO and Bi O on the flexible CC/MOFC substrate, the hierarchical electrode materials show an abrupt improvement of areal capacitances by around 50% and 100%, respectively, compared to those of the active materials on pristine carbon cloth. A flexible supercapacitor can be further assembled using two hierarchical electrodes, which demonstrates an energy density of 124.8 µWh cm at the power density of 2.55 mW cm .

High‐Performance Flexible Asymmetric Supercapacitors Facilitated by N‐doped Porous Vertical Graphene Nanomesh Arrays

“…Furthermore, the survey scan spectra of CC@NVGMs@MnO 2 indicate the presence of Mn, O, N, and C, with no visible impurities (Figure S6). The Mn 2p core‐level XPS signals of CC@NVGMs@MnO 2 samples in Figure a shows two obvious Mn 2p 1/2 and 2p 3/2 peaks at 653.8 and 642.0 eV, respectively, with a spin‐energy separation of 11.8 eV, which agree well with the previous reported data of MnO 2 . In addition, the core‐level XPS spectrum of O 1s exhibits a predominant peak of Mn−O−Mn at 529.8 eV originated from MnO 2 nanosheets and weak peaks of Mn−O−H (532.8 eV), corresponding to the structure water.…”

“…The Mn 2p core-level XPS signals of CC@NVGMs@MnO 2 samples in Figure 3a shows two obvious Mn 2p 1/2 and 2p 3/2 peaks at 653.8 and 642.0 eV, respectively, with a spin-energy separation of 11.8 eV, which agree well with the previous reported data of MnO 2 . [25] In addition, the core-level XPS spectrum of O 1s exhibits a predominant peak of MnÀ OÀ Mn at 529.8 eV originated from MnO 2 nanosheets and weak peaks of MnÀ OÀ H (532.8 eV), corresponding to the structure water. (Figure 3b) The peak located at 531.3 eV assigned to MnÀ OÀ C indicates the chemical contact between NVGMs and MnO 2 with a covalent bonding in the interface.…”

“…present a superhydrophilic ‘‘nanoglue’’ strategy by wrapping a thin nitrogen‐doped carbon layer on inert CC interface as the scaffold/electroactive species coupling bridge to fabricate hybrids electrodes for supercapacitors . On the other hand, in order to achieve larger specific surface area for loading active species, many previous works have constructed three‐dimensional nanohybrid structures such as carbon nanotubes, nitrogen‐doped carbon nanowire/tubes, nanocarbon nanowall, and vertical graphene on the surface of one‐dimensional carbon fibers . Typically, It functioning as bridging sites can tightly combine with active material to achieve high materials loading.…”

“…[21] On the other hand, in order to achieve larger specific surface area for loading active species, many previous works have constructed three-dimensional nanohybrid structures such as carbon nanotubes, nitrogen-doped carbon nanowire/tubes, nanocarbon nanowall, and vertical graphene on the surface of one-dimensional carbon fibers. [25][26][27][28][29] Typically, It functioning as bridging sites can tightly combine with active material to achieve high materials loading. The rational design of nanocomposites electrodes with three-dimensional hierarchical structure can boost the charge/mass transport and the utilization efficiency of active substances, also help to enhances the stability, thus achieving excellent device performances.…”

Ultrahigh‐Areal‐Capacitance Flexible Supercapacitor Electrodes Enabled by Conformal P3MT on Horizontally Aligned Carbon‐Nanotube Arrays

“…Among various energy storage devices, supercapacitors are most promising, bridging the gap between battery and capacitor . Supercapacitors have higher power density compared with batteries, and higher energy density than conventional dielectric capacitors . To develop flexible supercapacitor cells, many efforts have been dedicated to constructing mechanically flexible and robust electrodes.…”