A novel type of flexible fiber/wearable supercapacitor that is composed of two fiber electrodes - a helical spacer wire and an electrolyte - is demonstrated. In the carbon-based fiber supercapacitor (FSC), which has high capacitance performance, commercial pen ink is directly utilized as the electrochemical material. FSCs have potential benefits in the pursuit of low-cost, large-scale, and efficient flexible/wearable energy storage systems.

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Nitrogen-doped graphene was demonstrated as an efficient and alternative metal-free electrocatalyst for dye-sensitized solar cells. Electrochemical measurements showed that the nitrogen-doping process can remarkably improve the catalytic activity of graphene toward triiodide reduction, lower the charge transfer resistance, and thus enhance the corresponding photovoltaic performance. Furthermore, the nitrogen doping levels ranging from 3.5 at% to 18 at%, as well as the nitrogen states (including pyrrolic, pyridinic and quaternary configurations) in graphene, were controlled to interpret the roles of graphene structure in catalytic activity and device performance. The results suggested that the nitrogen states, rather than the total N content, have a significant effect on the catalytic activity. Both pyridinic and quaternary nitrogen states can provide active sites for promoting triiodide reduction reaction, probably due to the shift in redox potential and the lowered adsorption energy.

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N,N-Dimethylformamide (DMF) has been shown to be an efficient precursor solvent for the one-step deposition of perovskite thin films in photovoltaic applications. Here, the specific advantage DMF introduces during the perovskite crystallization process is elucidated through comparison with dimethylacetamide (DMAc), one of its homologues. The unique presence of a DMF-induced intermediate phase was verified for the first time and its positive functions to inhibit uncontrolled perovskite precipitation and facilitate homogeneous nucleation were demonstrated. When combined with a double blocking layer structure to prevent shunting, our planar heterojunction (PHJ) perovskite solar cells achieved a high power conversion efficiency of up to 13.8%. Our results uncover the origin of the widespread adoption of DMF in perovskite thin film deposition, and represent a helpful step towards judicious perovskite morphological control.

Due to their environmental sustainability and high efficiency, proton-exchange-membrane fuel cells (PEMFCs) are expected to be an essential type of energy source for electric vehicles, energy generation, and the space industry in the coming decades. Here, the recent developments regarding shape-controlled nanostructure catalysts are reviewed, with a focus on the stability of high-performance Pt-based catalysts and related mechanisms. The catalysts, which possess great activity, are still far from meeting the requirements of their applications, due to stability issues, especially in membrane electrode assemblies (MEAs). Thus, solutions toward the comprehensive performance of Pt-based catalysts are discussed here. The research trends and related theories that can promote the application of Pt-based catalysts are also provided.

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High-performance memristors were fabricated based on methyl ammonium lead halide perovskite materials and achieved an on–off ratio of 1.9 × 109.