Li-ion and Li-S batteries find enormous applications in different fields, such as electric vehicles and portable electronics. A separator is an indispensable part of the battery design, which functions as a physical barrier for the electrode as well as an electrolyte reservoir for ionic transport. The properties of the separators directly influence the performance of the batteries. Traditional polyolefin separators showed low thermal stability, poor wettability toward the electrolyte, and inadequate barrier properties to polysulfides. To improve the performance and durability of Li-ion and Li-S batteries, development of advanced separators is required. In this review, we summarize recent progress on the fabrication and application of novel separators, including the functionalized polyolefin separator, polymeric separator, and ceramic separator, for Li-ion and Li-S batteries. The characteristics, advantages, and limitations of these separators are discussed. A brief outlook for the future directions of the research in the separators is also provided.

Most existing bioadhesives, even those showing superiority in wound closure effectiveness, do not assist in the post-wound closure process. A bioinspired, in situ formed, double-dynamic-bond crosslinked hydrogel bioadhesive that is capable of efficiently closing open wounds and enabling post-wound closure care is reported. Catechol-modified ε-poly-l-lysine and oxidized dextran are employed as natural polymer backbones and they are in situ crosslinked using Schiff 's base dynamic bond and catecholFe coordinate dynamic bond through a process inspired by that used to cure marine mussel glue, forming a hydrogel bioadhesive. The unique double-dynamic-bond crosslinked structure endows the bioadhesive with higher mechanical and adhesive strength while retaining quick dissociation and good self-healing capacities. Accordingly, the bioadhesive can exhibit multiple desirable functions, such as dissolution on demand, repeatable adhesiveness, adhesive and mechanical strength sufficient for wound closure, injectability, and good biocompatibility (DREAMING). After efficiently closing skin incisions, the bioadhesive can be facilely removed or repeatedly close the reopened wounds, thus enabling post-wound closure care. On the basis of favorable functions in wound closure and the ability to enable post-wound closure care, the bioadhesive demonstrates great potential in dealing with skin wounds.

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We have reported the enhanced field emission properties of quasialigned 3C-SiC nanowires synthesized via catalyst assisted pyrolysis of polysilazane. The as-synthesized Al-doped SiC nanowires possess a tapered and bamboo-like structure with clear and tiny tips sized in several to tens of nanometers. The fabricated SiC nanowires have extremely low turn-on fields of 0.55−1.54 V μm−1 with an average of ∼1 V μm−1, which is the lowest one ever reported for any type of SiC emitters. The field-enhancement factor has been calculated to be 2983. The superior FE properties can be clearly attributed to the significant enhancements of the tapered and bamboo-like unique morphology and Al doping of SiC nanowires. Density functional theory calculations suggest that Al dopants in 3C-SiC nanowires could favor a more localized state near the Fermi energy, which improves the electron field emissions. We strongly believe that the present work will open a new insight in the fabrication of field emission sources with ultralow turn-on fields enhanced by both shape and doping.