α-Fe₂O₃@PANI Core–Shell Nanowire Arrays as Negative Electrodes for Asymmetric Supercapacitors

Abstract

Highly ordered three-dimensional α-Fe2O3@PANI core-shell nanowire arrays with enhanced specific areal capacity and rate performance are fabricated by a simple and cost-effective electrodeposition method. The α-Fe2O3@PANI core-shell nanowire arrays provide a large reaction surface area, fast ion and electron transfer, and good structure stability, which all are beneficial for improving the electrochemical performance. Here, high-performance asymmetric supercapacitors (ASCs) are designed using α-Fe2O3@PANI core-shell nanowire arrays as anode and PANI nanorods grown on carbon cloth as cathode, and they display a high volumetric capacitance of 2.02 mF/cm3 based on the volume of device, a high energy density of 0.35 mWh/cm3 at a power density of 120.51 mW/cm3, and very good cycling stability with capacitance retention of 95.77% after 10,000 cycles. These findings will promote the application of α-Fe2O3@PANI core-shell nanowire arrays as advanced negative electrodes for ASCs.

α-Fe2O3-Based Core-Shell-Nanorod–Structured Positiveand Negative Electrodes for a High-Performance α-Fe2O3/C//α-Fe2O3/MnOxAsymmetric Supercapacitor

“…As can be seen from the data in Fig. 7c, α 44 and also some carbon/graphene based SSCs, 45,46 and are comparable to that reported for VO x //VN-ASCs, i.e., 0.61 mWh/cm 3 , 0.5 mA/cm 2 . 39 The highest volumetric-power-density values for the present ASCs are almost similar, i.e., ∼155 mW/cm 3 at the load current of 7 mA, whereas the gravimetric power density is found to be higher for α- densities of the assembled ASCs are also compared with those reported in the literature 9,10,12,41,[47][48][49][50][51] and are shown in the Fig.…”

Constructing Hierarchical Tectorum‐like α‐Fe2O3/PPy Nanoarrays on Carbon Cloth for Solid‐State Asymmetric Supercapacitors

“…[19] As shown in Figure 2f,t he XPS peaks of Fe 2p 3/2 and Fe 2p 1/2 appear at 711 and 724.6 eV with apeak separation of 13.6 eV.Besides,two satellite peaks are at 716.4 and 730.7 eV,w hich is in accordance with previous reports. [7] Thus,the XPS result suggests that the PPy has been deposited on the surface of Fe 2 O 3 successfully. Furthermore,the conformal coating of PPy on the a-Fe 2 O 3 is confirmed by EDX elemental mapping analyses ( Figure S5 (Figure S6 b) indicates that the capacitance of the T-Fe 2 O 3 /PPy composites is higher than that of the pristine Fe 2 O 3 .…”

“…[1,2] To date, considerable effort has been made to design av ariety of hierarchical nano-/micro-architectures for supercapacitor electrodes. [5][6][7][8][9][10] Despite those important advances,the fabrication of complex a-Fe 2 O 3 hierarchical structures with well-defined secondary microstructures and rational surface engineering is difficult, owing to the lack of suitable and general methodologies.I n particular,t he current trend with supercapacitors lies in improving both the capacitance and rate performances at high current densities,b ya rchitectural configuration of complex heterostructured electrodes or asymmetric supercapacitor (ASC) devices. [5][6][7][8][9][10] Despite those important advances,the fabrication of complex a-Fe 2 O 3 hierarchical structures with well-defined secondary microstructures and rational surface engineering is difficult, owing to the lack of suitable and general methodologies.I n particular,t he current trend with supercapacitors lies in improving both the capacitance and rate performances at high current densities,b ya rchitectural configuration of complex heterostructured electrodes or asymmetric supercapacitor (ASC) devices.…”

Macroscopic‐Scale Three‐Dimensional Carbon Nanofiber Architectures for Electrochemical Energy Storage Devices

“…Li et al also obtained highly ordered 3D α-Fe 2 O 3 @PANI core-shell nanowire arrays on the carbon cloth by electrochemical position and annealing process. [138] Xu and Liu et al reported the electrochemical fabrication of well-ordered polypyrrole (PPy) nanowire arrays (NWAs) on the surfaces of carbon fibers in carbon cloth and constructed hierarchical structures. [139] Yu et al reported hierarchical core-shell-like MnO 2 nanostructures decorated MnO 2 hexagonal nanoplate arrays uniformly grown on carbon cloth fibers using a novel one-step electrochemical deposition method.…”