α‐Fe₂O₃ Based Carbon Composite as Pure Negative Electrode for Application as Supercapacitor

Abstract

Supercapacitors have drawn the great attention of researchers as green energy storage devices. Until now, serious positive electrodes for asymmetric cells have been developed noticeably. Nevertheless, negative electrode materials have been less explored, especially pseudocapacitive materials. In this review, the impact of the morphology and composition of hematite (α‐Fe2O3) based carbon composite as pure negative electrode are discussed. Besides, the specific capacitance, electrochemical stability, power density, and energy density of those materials are covered. The asymmetric supercapacitor using α‐Fe2O3 based carbon composite electrode shows high energy density, which can compete with batteries.

Recycling of iron from vanadium titanium magnetite tailings and its application in an asymmetric supercapacitor

“…Iron-series elements (Fe, Co, and Ni) containing MOFs and their derivatives have gained great concern in supercapacitors because of their worldwide abundance, low cost, tailorable architectures, multiple redox-active sites, wide potential window [23][24][25] and high theoretical-specific capacitance (3625 F g À1 ). 26 As shown in the previously reported literature, Fe 2 O 3 has been mainly prepared using pure iron salt as metal sources, such as Fe(NO 3 ) 3 , Fe 2 (SO 4 ) 3 , FeCl 3 , and Fe(CH 3 COO) 3 ; 27 the cost of these pure iron salt was high (about 40 000 $ t À1 ). As previously described, VTMT is a typical polymetallic iron tailing, the Fe content in VTMT is about 30% and the price is lower than 1/400th that of pure iron salt.…”

Performance comparison of distinct bismuth molybdate single phases for asymmetric supercapacitor applications

“…[8][9][10] The major limitation of supercapacitors is that they have a lower energy density (i.e., the total energy stored per volume), lower specific capacitance, and lower operation voltage than lithium-ion batteries. 11 The electron flow or the conductivity of the active material that relies on the surface area significantly influences the efficiency of these devices. 12,13 To overcome this barrier, researchers are develop-ing efficient electrode materials that should possess rapid kinetics of electrons and ions.…”

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

“…4,13,17 In the HMT crystal structure, Fe 3+ ions occupy two-thirds of the octahedral positions which are confined by the nearly perfect hexagonal close-packed oxygen lattice. 22,23 HMT is proved to be an expectant anode material for a supercapacitor due to its excellent theoretical S p (3625.0 F g −1 ). Nevertheless, researchers are determining approaches to conquer the low electrical conductivity (∼1014.0 S cm −1 ) and S p degradation because of the volume changes during multiple galvanic charge discharges (GCDs).…”