Morphology Effects on the Supercapacitive Electrochemical Performances of Iron Oxide/Reduced Graphene Oxide Nanocomposites

Abstract

The benzyl alcohol route is used to decorate reduced graphene oxide (RGO) nanosheets with iron oxide (FeOx) nanoparticles. The resulting FeOx/RGO composites combine both electrical double‐layer capacitive and pseudocapacitive behaviors of RGO and FeOx, respectively, owing to the hybrid nanostructure. In 1 M Na2SO4 aqueous electrolyte, the capacitance of the FeOx/RGO electrode reaches 126 F g−1 in a negative potential range from −0.8 to 0.0 V (vs. Ag/AgCl) and 97 F g−1 in the extended potential window from −0.8 to +0.7 V (vs. Ag/AgCl). By using the benzyl alcohol route, a higher concentration of iron precursor leads to full surface coverage of the RGO nanosheets by smaller FeOx nanoparticles, forming a close‐packed layer that limits the restacking of RGO nonosheets in the dry state. The resulting FeOx/RGO composite gains the same power capability as RGO and a higher energy density than raw FeOx, owing to this well‐designed morphology,.

Chemical Modification of Graphene Oxide through Diazonium Chemistry and Its Influence on the Structure–Property Relationships of Graphene Oxide–Iron Oxide Nanocomposites

“…[5,34] Iron oxide nanoparticles, particularly magnetite (Fe 3 O 4 ), are regarded as promising pseudocapacitive materials because of their low cost, ease of preparation, minimum environmental impact and high theoretical capacitance. [35,36] Several approaches to the synthesis of carbon-iron oxide nanocomposites have been described. In-situ synthesis of iron oxide nanoparticles, either by co-precipitation methodo rb ys ol-gel approaches, is the most employed strategy.…”

MOF‐Derived Porous NixFe3‐xO4 Nanotubes with Excellent Performance in Lithium‐Ion Batteries

“…[8,9] Besides, traditional lithium-storage materials often suffer from drawbacks such as seriousc apacity loss and limited cycling ability when cycling at high rates, which could mainly be ascribed to the high polarization and poor conductiona bilitieso ft he electrode materials. [8] Recently,t ransition-metal oxides( MO x ,M : Ti, [10] Fe, [11] Co, [12] Ni, [13] Cu, [14] Zn) [15] have been used in intercalation, conversion,a nd alloying mechanisms, attracting considerable attention as secure and low-cost anode materials for next-generation LIBs, owing to their excellent theoretical specific capacities that are typically 2-4 times highert han that of the graphite-basede lectrode materials. In particular,t ernary iron-based oxides represent one of the most widely studied candidates for high-performance anode materials in large-scale LIBs, which is attributed to the fact that they are cheap, abun-dant, environmentally friendly,a nd exhibit excellent theoretical capacities for LIBs (for instance, about 1000 mAh g À1 for Fe 2 O 3 ).…”

Iron‐Based Supercapacitor Electrodes: Advances and Challenges

“…Despite these achievements, the capacitive performances of most current FeOOH electrodes are not yet satisfied, especially for rate capability and cycling stability. [119] A high specific capacitance of 126 F g −1 was achieved for FeO x /rGO electrode in a negative potential range from −0.8 to 0 V. researchers.…”

“…[56] Their results reveal that the electrochemical performance of the FeOOH/rGO materials largely depends on the quantity of rGO and size of FeOOH NRs. [119][120][121][122] For instance, a well-dispersed mesoporous FeO x nanowires/CNT composite electrode fabricated via spray deposition gave a maximum capacitance of 312 F g −1 at 2 mV s −1 in an aqueous Na 2 SO 3 electrolyte. Despite these achievements, the capacitive performances of most current FeOOH electrodes are not yet satisfied, especially for rate capability and cycling stability.…”