Analysis of XPS spectra of Fe2+ and Fe3+ ions in oxide materials

X-ray photoelectron spectroscopy: Towards reliable binding energy referencing

A low-cost high-performance solid-state flexible asymmetric supercapacitor (ASC) with α-MnO2 nanowires and amorphous Fe2O3 nanotubes grown on flexible carbon fabric is first designed and fabricated. The assembled novel flexible ASC device with an extended operating voltage window of 1.6 V exhibits excellent performance such as a high energy density of 0.55 mWh/cm3 and good rate capability. The ASC devices can find numerous applications as effective power sources, such as powering color-switchable sun glasses and smart windows.

Low-Cost High-Performance Solid-State Asymmetric Supercapacitors Based on MnO2 Nanowires and Fe2O3 Nanotubes

Fe3O4 has long been regarded as a promising anode material for lithium ion battery due to its high theoretical capacity, earth abundance, low cost, and nontoxic properties. However, up to now no effective and scalable method has been realized to overcome the bottleneck of poor cyclability and low rate capability. In this article, we report a bottom-up strategy assisted by atomic layer deposition to graft bicontinuous mesoporous nanostructure Fe3O4 onto three-dimensional graphene foams and directly use the composite as the lithium ion battery anode. This electrode exhibits high reversible capacity and fast charging and discharging capability. A high capacity of 785 mAh/g is achieved at 1C rate and is maintained without decay up to 500 cycles. Moreover, the rate of up to 60C is also demonstrated, rendering a fast discharge potential. To our knowledge, this is the best reported rate performance for Fe3O4 in lithium ion battery to date.

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Three-Dimensional Graphene Foam Supported Fe3O4 Lithium Battery Anodes with Long Cycle Life and High Rate Capability

Multi-shelled α-Fe2O3 hollow microspheres were synthesized using carbonaceous microsphere sacrificial templates and utilized for high capacity anode materials in lithium ion batteries (LIBs). Structural aspects including the shell thickness, number of internal multi-shells, and shell porosity were controlled by synthesis parameters to produce hollow microspheres with maximum lithium capacity and stable cycling behavior. Thin, porous, hollow microspheres with three concentric multi-shells showed the best cycling performance, demonstrating excellent stability and a reversible capacity of up to 1702 mA h g−1 at a current density of 50 mA g−1. The electrode performance is attributed to the large specific surface area and enhanced volumetric capacity of the multi-shelled hollow spheres that provide maximum lithium storage, while the porous thin shells facilitate rapid electrochemical kinetics and buffer mechanical stresses that accompany volume changes during de/lithiation.

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Toru Yamashita

Papers

Analysis of XPS spectra of Fe2+ and Fe3+ ions in oxide materials

Effect of curve fitting parameters on quantitative analysis of Fe0.94O and Fe2O3 using XPS

Erratum to “Analysis of XPS spectra of Fe2+ and Fe3+ ions in oxide materials” [Appl. Surf. Sci. 254 (2008) 2441–2449]

Reply to Paparazzo

Erratum to Analysis of XPS spectra of Fe2+ and Fe3+ ions in oxide materials