Symmetric transparent and flexible supercapacitor based on bio-inspired graphene-wrapped Fe₂O₃ nanowire networks

Abstract

Transition metal oxides with high specific capacitance materials are ideal for a new generation of high-performance transparent supercapacitors but are rarely reported. Commonly, the synthesis of the required nanostructured materials is a crucial step required to achieve the transparency of the device. In this study, a FeO nanowire network transparent film is developed simply through air-solution interface reactions and wrapped in graphene shells for use as transparent electrodes. The FeO nanowire networks surrounded by the graphene layer exhibit an effective encapsulation structure, providing rapid three-dimensional electron and ion transport pathways. The specific areal capacitance (3.3 mF cm at a scan rate of 10 mV s) was greatly improved, which is at least one hundred times higher than that for transparent devices based on planar chemical vapor deposition graphene. Furthermore, the films have a power density of 191.3 W cm, which is higher than that of electrolytic capacitors, an energy density of 8 mWh cm, which is comparable to that of lithium thin-film batteries, and superior cycling stability.

Iron oxides nanobelt arrays rooted in nanoporous surface of carbon tube textile as stretchable and robust electrodes for flexible supercapacitors with ultrahigh areal energy density and remarkable cycling-stability

“…The Coulombic efficiency η is as high as 97.5% after 10,000 cycles. This indicates remarkable cycling stability of the electrode, much better than other composite electrodes especially using commercial carbon cloth as substrates, such as Fe 2 O 3 nanorods@NiO nanosheets on carbon cloth (96.2% after 3,000 cycles) 15 , Graphene-wrapped Fe 2 O 3 nanowire networks (78.2% after 5,000 cycles) 48 , and porous Fe 2 O 3 nanosheets on carbon fabric (93% capacitance after 4,000 cycles) (Table S1) 44 . After the cycle measurements, the Fe 2 O 3 nanobelt arrays were still well attached on the CTs (Figure S8, Supporting Information), confirming the strong bonding between Fe 2 O 3 nanobelt and each CT.…”

“…Also, this value is higher than three times of those for Fe 2 O 3 nanorods@graphene foam on Ni foam (572 mF cm −2 ) 49 , Fe 2 O 3 nanorods@NiO nanosheets on carbon cloth (557 mF cm −2 ) 15 , and Fe 2 O 3 nanoparticles@graphene foam-CNT (470.5 mF cm −2 ) 50 . The data for the performance comparison are shown in Table S1 15,27,[44][45][46][47][48][49][50] .…”

A Micromolding Method for Transparent and Flexible Thin‐Film Supercapacitors and Hybrid Supercapacitors

“…At 550 nm, the transmittance of a single electrode is ≈62.5%, which decreases to 42.9% for the corresponding assembled supercapacitor. [10] These films have a power density of 191.3 W cm −3 and an energy density of 8 mWh cm −3 , which is comparable to that of lithium-ion thin-film batteries. All the above examples, however, suffer from the problem that the transparency of the full cell decreases significantly upon stacking the two electrodes due to their random structure.…”

Investigations on performance of PEDOT:PSS/V2O5 hybrid symmetric supercapacitor with redox electrolyte

“…[1][2][3] But since supercapacitors suffer from the limitations in the energy density, attempts are widely made to employ hybrids of materials offering EDLC and pseudocapacitance. [4][5][6] Different metal oxides like RuO 2 , MnO 2 , and so forth, some conducting polymers (CPs) like polyaniline (PANI), polypyrrole (PPy) and polythiophene and its derivatives exhibit excellent redox properties. Hence they are suggested to be well suited to act as pseudocapacitors.…”