A polymer‐based magnesium (Mg) electrolyte is vital for boosting the development of high‐safety and flexible Mg batteries by virtue of its enormous advantages, such as significantly improved safety, potentially high energy density, ease of fabrication, and structural flexibility. Herein, a novel polytetrahydrofuran‐borate‐based gel polymer electrolyte coupling with glass fiber is synthesized via an in situ crosslinking reaction of magnesium borohydride [Mg(BH4)2] and hydroxyl‐terminated polytetrahydrofuran. This gel polymer electrolyte exhibits reversible Mg plating/stripping performance, high Mg‐ion conductivity, and remarkable Mg‐ion transfer number. The Mo6S8/Mg batteries assembled with this gel polymer electrolyte not only work well at wide temperature range (−20 to 60 °C) but also display unprecedented improvements in safety issues without suffering from internal short‐circuit failure even after a cutting test. This in situ crosslinking approach toward exploiting the Mg‐polymer electrolyte provides a promising strategy for achieving large‐scale application of Mg‐metal batteries.

Rechargeable magnesium (Mg) metal batteries are provided with potential advantages over lithium counterparts with respect to volumetric capacity and natural abundance (equivalent to low cost and sustainability). However, Mg metal anodes suffer from surface passivating behavior among numerous conventional Mg electrolytes, leading to irreversible Mg plating/stripping behavior. Herein, a modified Mg metal anode with a bismuth (Bi)-based artificial protective layer has been obtained via a facile solution process (soaking briefly in bismuth trichloride solution). This Bi-based protective layer is mainly composed of ion-conducting Bi metal and corresponding alloy and electronically insulating magnesium chloride. Various electrochemical tests and interface characterizations have proved that the protected Mg electrodes effectively inhibit the harmful parasitic reaction between Mg metal and noncorrosive Mg electrolyte, which further enables suppression of uneven growth during repeated Mg stripping/plating. More importantly, the assembled Mg–Cu2–x S and Mg–O2 full batteries utilizing the as-modified Mg anodes all deliver remarkably improved performance owing to the superior protection properties of a Bi-based artificial layer. These novel findings will inspire lot of efforts to modify the Mg metal anode with targeted surface coatings for high-performance rechargeable Mg batteries.

Tungsten oxynitride nanowires were generated by the reaction of ammonia with ultra-thin tungsten oxide nanowires which were themselves prepared by a simple solvo-thermal treatment of tungsten chloride in a cyclohexanol solvent. The resulting tungsten oxynitride nanowires exhibited a high specific surface area of 221 m 2 g 21 , even exceeding that of 151 m 2 g 21 for the bundled and ultra-thin tungsten oxide nanowire precursor. The observed weak, temperature-independent paramagnetism indicates that the tungsten oxynitride nanowires are metallic, but no superconducting transition was observed above 2 K.

Low-temperature magnetic properties of hematite nanorods, prepared by both iron−water vapor reactions (sample 1) and hydrothermal methods (sample 2), were studied by superconducting quantum interference device (SQUID) magnetometry. The Morin transition temperature was found to be 122 K in hematite nanorod sample 1, and an unexpected phenomenon was found under an applied field of 10 Oe. These nanorods (sample 1) show an abrupt decrease of the magnetic susceptibility at ca. 122 K, contrary to the abrupt increase normally attributed to the Morin transition in bulk hematite. The origin of this phenomenon can be traced to the probable coherence of the one-dimensional shape anisotropy with the magnetocrystalline anisotropy. In contrast, no obvious Morin transition was found in hematite nanorod sample 2.