recognized that the safety of LiBs is closely associated with the highly flammable separator and liquid organic electrolytes, for example, polypropylene (PP), ethylene carbonate (EC), and diethyl carbonate (DEC). To this date, considerable efforts have been focused on overcoming the inflammable problem, such as: (1) adding refractories into electrolytes, [11] (2) tracing dendrite evolution via a smart separator for early warning, [12] (3) coating the separator with a ceramic layer for thermal-switching the current collector. [13] Although it is efficient to reduce the flammability, the risk of battery fire still exists, especially for lithium metal battery with excessive metal lithium. In addition, these batteries were mostly traditional LiBs (LiFePO 4 , LiCoO 2 , LiMn 2 O 4 , etc.), which still cannot meet the increasing energy density requirement of next-generation batteries. [7,14,15] Owning a specific capacity as high as 1675 mA h g −1 , lithium-sulfur (Li-S) batteries are promising for next-generation energy storage. Despite great promise, the shuttle effect, due to the dissolution of polysulfides (PS) in the electrolyte, leading to a rapidly fading capacity with recharge process, still impedes the commercialization of Li-S batteries. Tremendous efforts have been devoted to developing advanced cathodes with suppressed shuttle Lithium-sulfur (Li-S) batteries are of considerable research interest for their application potentials in high-density energy storage. However, the practical application of Li-S batteries is severely plagued by polysulfide (PS) dissolution and serious safety concerns caused by flammable sulfur and polymer separators. Herein, a nonflammable multifunctional separator for efficient suppression of PS dissolution and high-temperature performance of Li-S batteries is reported. Polyacrylonitrile (PAN) and ammonium polyphosphate (APP) are electrospun into a multifunctional separator (PAN@APP) for stable and safe Li-S batteries. Owing to the abundant amine groups and phosphate radical in APP, the PAN@APP separator has strong binding interactions with PS, which exerts strong charge repulsion to suppress the transport of negatively charged PS ions and free radicals. Furthermore, refractory APP ensures the stability of the battery at high temperatures. Using the PAN@APP separator, the Li-S battery demonstrates a capacity retention of 83% over 800 cycles. This work provides a robust materials platform for stable and safe Li-S batteries and points to a direction to close the current gap facing the commercialization of high-energy next-generation electrochemical conversion/storage devices.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/aenm.201802441.With the rapidly increasing demand for electric vehicles, lithium-ion batteries (LiBs) have attracted extensive attention owing to their high specific energy density, low cost, and rechargeable performances. [1][2][3][4][5][6][7][8][9][10] However, increased complexity of application conditio...

Due to unprecedented features including high‐energy density, low cost, and light weight, lithium–sulfur batteries have been proposed as a promising successor of lithium‐ion batteries. However, unresolved detrimental low Li‐ion transport rates in traditional carbon materials lead to large energy barrier in high sulfur loading batteries, which prevents the lithium–sulfur batteries from commercialization. In this report, to overcome the challenge of increasing both the cycling stability and areal capacity, a metallic oxide composite (NiCo2O4@rGO) is designed to enable a robust separator with low energy barrier for Li‐ion diffusion and simultaneously provide abundant active sites for the catalytic conversion of the polar polysulfides. With a high sulfur‐loading of 6 mg cm−2 and low sulfur/electrolyte ratio of 10, the assembled batteries deliver an initial capacity of 5.04 mAh cm−2 as well as capacity retention of 92% after 400 cycles. The metallic oxide composite NiCo2O4@rGO/PP separator with low Li‐ion diffusion energy barrier opens up the opportunity for lithium–sulfur batteries to achieve long‐cycle, cost‐effective operation toward wide applications in electric vehicles and electronic devices.

Colloidal lithography technology based on monolayer colloidal crystals (MCCs) is considered as an outstanding candidate for fabricating large‐area patterned functional nanostructures and devices. Although many efforts have been devoted to achieve various novel applicatons, the quality of MCCs, a key factor for the controllability and reproducibility of the patterned nanostructures, is often overlooked. In this work, an interfacial capillary‐force‐driven self‐assembly strategy (ICFDS) is designed to realize a high‐quality and highly‐ordered hexagonal monolayer MCCs array by resorting the capillary effect of the interfacial water film at substrate surface as well as controlling the zeta potential of the polystyrene particles. Compared with the conventional self‐assembly method, this approach can realize the reself‐assembly process on the substrate surface with few colloidal aggregates, vacancy, and crystal boundary defects. Furthermore, various typical large‐scale nanostructure arrays are achieved by combining reactive ion etching, metal‐assisted chemical etching, and so forth. Specifically, benefiting from the as‐fabricated high‐quality 2D hexagonal colloidal crystals, the surface plasmon resonance (SPR) sensors achieve an excellent refractive index sensitivity value of 3497 nm RIU−1, which is competent for detecting bovine serum albumin with an ultralow concentration of 10−8 m. This work opens a window to prepare high‐quality MCCs for more potential applications.

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