Single-Step Preparation of Ultrasmall Iron Oxide-Embedded Carbon Nanotubes on Carbon Cloth with Excellent Superhydrophilicity and Enhanced Supercapacitor Performance

Abstract

Nanocomposites consisting of carbon materials and metal oxides are generally preferred as anodes in electrochemical energy storage. However, their low capacitance limits the achieved energy density of supercapacitors (SCs) in aqueous electrolytes. Herein, we propose a rapid combustion strategy to construct a novel electrode architectureultrasmall Fe2O3 anchoring on carbon nanotubes (FeO–CNT)as a superhydrophilic and flexible anode for SCs. In 1 M Na2SO4 aqueous electrolyte, such an FeO–CNT-20 anode presents a high capacitance of 483.4 mF cm–2 (326 F g–1) at 1 mA cm–2. The aqueous asymmetric supercapacitor devices (ASCs) assembled by FeO–CNT-20 and MnO2 present a maximum operating potential of 2.0 V with a high areal energy density of 0.11 mWh cm–2 at a power density of 0.5 mW cm–2. The flexible solid-state ASCs display an energy density of 0.99 mWh cm–3 at 14.3 mW cm–3. The rapidly prepared FeO–CNT not only offers an attractive electrode for SCs but also would open up exciting new avenues to the rational design and large-scale preparation of Fe2O3-based nanocomposites for electrochemical energy storage.

Nitrogen–Oxygen Co-Doped Carbon-Coated Porous Silica/Carbon Nanotube Composites: Implications for High-Performance Capacitors

“…The performance of electrochemical capacitors is closely linked to R ct , which means that the larger the charge transfer resistance is, the lower the specific capacitance is . The R ct value of CNT@mSiO 2 @NC-24 is 1.42 Ω, indicating a faster ion migration and lower interface resistance . The vertical line near 90° in the low-frequency region belongs to the Warburg impedance ( Z w ) and is associated with the diffusion of OH– ions.…”

“…54 The R ct value of CNT@mSiO 2 @NC-24 is 1.42 Ω, indicating a faster ion migration and lower interface resistance. 55 The vertical line near 90°in the low-frequency region belongs to the Warburg impedance (Z w ) and is associated with the diffusion of OH− ions. In comparison to CNT@mSiO 2 @NC, CNT@mSiO 2 @NC-12, and CNT@ mSiO 2 @NC-48, the CNT@mSiO 2 @NC-24 electrode has a steeper and shorter Warburg line, indicating that it shows an ideal capacitance behavior and lower diffusion resistance.…”

Perspective Chapter: Graphene Based Nanocomposites for Supercapacitor Electrodes

“…Iron oxides (FeOx) are attractive electrodes among transition metal oxides due to their large capacitance, low price, varied oxidation states, and environment friendly nature [31][32][33][34]. While the poor conductivity of iron oxide has hindered its super capacitive applicability, combining Fe 3 O 4 with graphene can be regarded as a viable solution technique.…”

Rational La-doped hematite as an anode and hydrous cobalt phosphate as a battery-type electrode for a hybrid supercapacitor

“…[18][19][20] Fe is the fourth most ample element on earth. 21 Iron oxide exists in 16 different phases. HMT is regularly implemented in nanomaterials-based applications owing to their wide availability, high sensitivity, and less toxicity.…”