Three-dimensional network structured a-Fe 2 O 3 was prepared by a facile chemical corrosion of a stainless steel plate followed by thermal oxidation. When the architecture was directly used as an electrode for lithium ion batteries (LIBs), a high reversible capacity of 858.2 mA h g À1 was obtained at a current density of 200 mA g À1 for the 2nd discharge. Especially, it retained a capacity of 1105.6 mA h g À1 at the 100th discharge-charge cycle. The mechanism behind the capacity increase with cycling has been investigated based on the capacity changes in different voltage regions. After cycling with various current densities, it can deliver a capacity of 520.0 mA h g À1 at a current density as high as 5000 mA g À1 , indicating that the electrode prepared by such a simple route can be a promising candidate for high-power LIBs.

To satisfy the increasing energy demands of portable electronics, electric vehicles, and miniaturized energy storage devices, improvements to lithium‐ion batteries (LIBs) are required to provide higher energy/power densities and longer cycle lives. Group IVA element (Si, Ge, Sn)‐based alloying/dealloying anodes are promising candidates for use as electrodes in next‐generation LIBs owing to their extremely high gravimetric and volumetric capacities, low working voltages, and natural abundances. However, due to the violent volume changes that occur during lithium‐ion insertion/extraction and the formation of an unstable solid electrolyte interface, the use of Group IVA element‐based anodes in commercial LIBs is still a great challenge. Evaluating the electrochemical performance of an anode in a full‐cell configuration is a key step in investigating the possible application of the active material in LIBs. In this regard, the recent progress and important approaches to overcoming and alleviating the drawbacks of Group IVA element‐based anode materials are reviewed, such as the severe volume variations during cycling and the relatively brittle electrode/electrolyte interface in full‐cell LIBs. Finally, perspectives and future challenges in achieving the practical application of Group IVA element‐based anodes in high‐energy and high‐power‐density LIB systems are proposed.

N-doped amorphous carbon coated Fe3O4/SnO2 coaxial nanofibers were prepared via a facile approach. The core composite nanofibers were first made by electrospinning technology, then the shells were conformally coated using the chemical bath deposition and subsequent carbonization with polydopamine as a carbon source. When applied as a binder-free self-supported anode for lithium ion batteries, the coaxial nanofibers displayed an enhanced electrochemical storage capacity and excellent rate performance. The morphology of the interwoven nanofibers was maintained even after the rate cycle test. The superior electrochemical performance originates in the structural stability of the N-doped amorphous carbon shells formed by carbonizing polydopamine.

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Mesoporous materials have been extensively studied for various applications due to their high specific surface areas and well-interconnected uniform nanopores. Great attention has been paid to synthesizing stable functional mesoporous metal oxides for catalysis, energy storage and conversion, chemical sensing, and so forth. Heteroatom doping and surface modification of metal oxides are typical routes to improve their performance. However, it still remains challenging to directly and conveniently synthesize mesoporous metal oxides with both a specific functionalized surface and heteroatom-doped framework. Here, we report a one-step multicomponent coassembly to synthesize Pt nanoparticle-decorated Si-doped WO3 nanowires interwoven into 3D mesoporous superstructures (Pt/Si-WO3 NWIMSs) by using amphiphilic poly­(ethylene oxide)-block-polystyrene (PEO-b-PS), Keggin polyoxometalates (H4SiW12O40) and hydrophobic (1,5-cyclooctadiene)­dimethylplatinum­(II) as the as structure-directing agent, tungsten precursor and platinum source, respectively. The Pt/Si-WO3 NWIMSs exhibit a unique mesoporous structure consisting of 3D interwoven Si-doped WO3 nanowires with surfaces homogeneously decorated by Pt nanoparticles. Because of the highly porous structure, excellent transport of carriers in nanowires, and rich WO3/Pt active interfaces, the semiconductor gas sensors based on Pt/Si-WO3 NWIMSs show excellent sensing properties toward ethanol at low temperature (100 °C) with high sensitivity (S = 93 vs 50 ppm), low detection limit (0.5 ppm), fast response–recovery speed (17–7 s), excellent selectivity, and long-term stability.