The research field on perovskite solar cells (PSCs) is seeing frequent record breaking in the power conversion efficiency (PCE). However, organic-inorganic hybrid halide perovskites and organic additives in common hole-transport materials (HTMs) exhibit poor stability against moisture and heat. Here we report the successful fabrication of all-inorganic PSCs without any labile or expensive organic components. The entire fabrication process can be operated in ambient environment without humidity control (e.g., a glovebox). Even without encapsulation, the all-inorganic PSCs present no performance degradation in humid air (90-95% relative humidity, 25 °C) for over 3 months (2640 h) and can endure extreme temperatures (100 and -22 °C). Moreover, by elimination of expensive HTMs and noble-metal electrodes, the cost was significantly reduced. The highest PCE of the first-generation all-inorganic PSCs reached 6.7%. This study opens the door for next-generation PSCs with long-term stability under harsh conditions, making practical application of PSCs a real possibility.
Rechargeable magnesium batteries have attracted increasing attention due to the high theoretical volumetric capacities, dendrite formation-free characteristic and low cost of Mg metal anodes. However, the development of magnesium batteries is seriously hindered by the lack of capable cathode materials with long cycling life and fast solid-state diffusion kinetics for highly-polarized divalent Mg ions. Herein, vanadium tetrasulfide (VS ) with special one-dimensional atomic-chain structure is reported to be able to serve as a favorable cathode material for high-performance magnesium batteries. Through a surfactant-assisted solution-phase process, sea-urchin-like VS nanodendrites are controllably prepared. Benefiting from the chain-like crystalline structure of VS , the S dimers in the VS nanodendrites provide abundant sites for Mg insertion. Moreover, the VS atomic-chains bonded by weak van der Waals forces are beneficial to the diffusion kinetics of Mg ions inside the open channels of VS . Through a series of systematic ex situ characterizations and density functional theory calculations, the magnesiation/demagnesiation mechanism of VS are elucidated. The VS nanodendrites present remarkable performance for Mg storage among existing cathode materials, exhibiting a remarkable initial discharge capacity of 251 mAh g at 100 mA g and an impressive long-term cyclability at large current density of 500 mA g (74 mAh g after 800 cycles).
Metal oxide‐based nanomaterials are widely studied because of their high‐energy densities as anode materials in lithium‐ion batteries. However, the fast capacity degradation resulting from the large volume expansion upon lithiation hinders their practical application. In this work, the preparation of walnut‐like multicore–shell MnO encapsulated nitrogen‐rich carbon nanocapsules (MnO@NC) is reported via a facile and eco‐friendly process for long‐cycling Li‐ion batteries. In this hybrid structure, MnO nanoparticles are uniformly dispersed inside carbon nanoshells, which can simultaneously act as a conductive framework and also a protective buffer layer to restrain the volume variation. The MnO@NC nanocapsules show remarkable electrochemical performances for lithium‐ion batteries, exhibiting high reversible capability (762 mAh g−1 at 100 mA g−1) and stable cycling life (624 mAh g−1 after 1000 cycles at 1000 mA g−1). In addition, the soft‐packed full batteries based on MnO@NC nanocapsules anodes and commercial LiFePO4 cathodes present good flexibility and cycling stability.
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