Poor stability of organic–inorganic halide perovskite materials in humid condition has hindered the success of perovskite solar cells in real applications since controlled atmosphere is required for device fabrication and operation, and there is a lack of effective solutions to this problem until now. Here we report the use of lead (II) thiocyanate (Pb(SCN)2) precursor in preparing perovskite solar cells in ambient air. High-quality CH3NH3PbI3−x(SCN)x perovskite films can be readily prepared even when the relative humidity exceeds 70%. Under optimized processing conditions, we obtain devices with an average power conversion efficiency of 13.49% and the maximum efficiency over 15%. In comparison with typical CH3NH3PbI3-based devices, these solar cells without encapsulation show greatly improved stability in humid air, which is attributed to the incorporation of thiocyanate ions in the crystal lattice. The findings pave a way for realizing efficient and stable perovskite solar cells in ambient atmosphere.

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Nitrogen-doped, hierarchical porous carbons with a high surface area were simply prepared from gelatin using nano-ZnO as both the template and activating agent.

Powering lithium‐ion batteries (LIBs) by light‐irradiation will bring a paradigm shift in energy‐storage technologies. Herein, a photoaccelerated rechargeable LIB employing SnO2/TiO2 heterojunction nanoarrays as a multifunctional anode is developed. The electron–hole pairs generated by the LixTiO2 (x ≥ 0) under light irradiation synergistically enhance the lithiation kinetics and electrochemical reversibility of both SnO2 and TiO2. Specifically, the electrons can quickly pour into the SnO2 and the generated Sn due to the more positive conduction band potentials (vs TiO2), and mean while the holes also promote the intercalation of Li+ into TiO2 by reaching charge balance. A remarkable increase in areal specific capacity is therefore achieved from 1.91 to 3.47 mAh cm−2 at 5 mA cm−2. More impressively, there is no capacity loss even through 100 cycles, which is the best report for photorechargeable LIBs to date, owing to the strong and stable photoresponse current. This finding exhibits a feasible pathway to break the limitation in the energy density of LIBs by the efficient conversion and storage of solar energy.

Summary The lead–acid battery (LAB) has been one of the main secondary electrochemical power sources with wide application in various fields (transport vehicles, telecommunications, information technologies, etc.). It has won a dominating position in energy storage and load‐leveling applications. However, the failure of LAB becomes the key barrier for its further development and application. Therefore, understanding the failure modes and mechanism of LAB is of great significance. The failure modes of LAB mainly include two aspects: failure of the positive electrode and negative electrode. The degradations of active material and grid corrosion are the two major failure modes for positive electrode, while the irreversible sulfation is the most common failure mode for the negative electrode. Introduction of carbon materials to the negative electrodes of LAB could suppress sulfation problem and enhance the battery performance efficiently. This paper will attempt here to pull together observations made by previous research to obtain a more comprehensive and integrative view of LAB failure modes. Moreover, according to a detail investigation to the battery market, we have drawn an objective and optimistic conclusion of LAB prospect. Copyright © 2016 John Wiley & Sons, Ltd.