Deficient spinel ZnMn2O4 with a hollow porous structure was prepared through a solvothermal carbon template dispersed by polyvinyl pyrrolidone.

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The sodium (Na)‐metal anode with high theoretical capacity and low cost is promising for construction of high‐energy‐density metal batteries. However, the unsatisfactory interface between Na and the liquid electrolyte induces tardy ion transfer kinetics and dendritic Na growth, especially at ultralow temperature (−40 °C). Herein, an artificial heterogeneous interphase consisting of disodium selenide (Na2Se) and metal vanadium (V) is produced on the surface of Na (Na@Na2Se/V) via an in situ spontaneous chemical reaction. Such interphase layer possesses high sodiophilicity, excellent ionic conductivity, and high Young's modulus, which can promote Na‐ion adsorption and transport, realizing homogenous Na deposition without dendrites. The symmetric Na@Na2Se/V cell exhibits outstanding cycling life span of over 1790 h (0.5 mA cm−2/1 mAh cm−2) in carbonate‐based electrolyte. More remarkably, ab initio molecular dynamics simulations reveal that the artificial Na2Se/V hybrid interphase can accelerate the desolvation of solvated Na+ at −40 °C. The Na@Na2Se/V electrode thus exhibits exceptional electrochemical performance in symmetric cell (over 1500 h at 0.5 mA cm−2/0.5 mAh cm−2) and full cell (over 700 cycles at 0.5 C) at −40 °C. This work provides an avenue to design artificial heterogeneous interphase layers for superior high‐energy‐density metal batteries at ambient and ultralow temperatures.

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Aqueous battery has been gained much more interest for large-scale energy storage fields due to its excellent safety, high power density and low cost. Cryptomelane-type KMn8O16 confirmed by X-ray diffraction (XRD) was successfully synthesized by a modified hydrothermal method, followed by annealed at 400°C for 3 h. The morphology and microstructure of as-prepared KMn8O16 investigated by field-emission scanning electron microscopy (FE-SEM) with the energy spectrum analysis (EDS) and transmission electron microscopy (TEM) demonstrate that one-dimensional nano rods with the length of about 500 nm constitute the microspheres with the diameter about 0.5~2 μm. The cyclic voltammetry measurement displays that the abundant intercalation of zinc ions on the cathode takes place during the initial discharge process, indicating that cryptomelane-type KMn8O16 can be used as the potential cathode material for aqueous zinc ion batteries. The electrode shows a good cycling performance with a reversible capacity of up to 77.0 mAh/g even after 100 cycles and a small self-discharge phenomenon.

Sodium metal has been regarded as the potential alternative for metal batteries owing to its advantages of high theoretical capacity and abundant reserves. Nevertheless, propagation of Na dendrites can boost the interfacial instability of Na metal, retarding its practical implementation. Thus, the Na–Ga alloy layer is designed and fabricated by in situ rolling of metal Ga on the surface of Na metal. This alloy layer possesses good sodiophilicity, which can effectively protect Na metal and favor the uniform Na+ deposition, obtaining the inhibition of Na dendrites growth. Consequently, the symmetric cells assembled by the alloy‐layer protected Na metal electrodes (NGAL‐Na||NGAL‐Na) have a long lifetime (468 h) even under a high plating/stripping capacity of 6 mAh cm−2 in carbonate electrolyte. The full battery of NGAL‐Na||Na3V2(PO4)3 is able to sustain an excellent rate capability of 100 mAh g−1 after 500 cycles at 10 C under ambient temperature. This work provides a new route to prevent metal anodes from severe dendrite growth, and paves the way toward safer and stable‐performing metal‐based rechargeable batteries.

The next-generation secondary batteries including the sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) are regarded as the most promising candidate for the application to large-scale energy storage system profited from...