Vanadium-based materials have been extensively studied as promising cathode materials for zinc-ion batteries because of their multiple valences and adjustable ion-diffusion channels. However, the sluggish kinetics of Zn-ion intercalation and less stable layered structure remain bottlenecks that limit their further development. The present work introduces potassium ions to partially substitute ammonium ions in ammonium vanadate, leading to a subtle shrinkage of lattice distance and the increased oxygen vacancies. The resulting potassium ammonium vanadate exhibits a high discharge capacity (464 mAh g–1 at 0.1 A g–1) and excellent cycling stability (90% retention over 3000 cycles at 5 A g–1). The excellent electrochemical properties and battery performances are attributed to the rich oxygen vacancies. The introduction of K+ to partially replace NH4 + appears to alleviate the irreversible deammoniation to prevent structural collapse during ion insertion/extraction. Density functional theory calculations show that potassium ammonium vanadate has a modulated electron structure and a better zinc-ion diffusion path with a lower migration barrier.

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Aqueous rechargeable Zn metal batteries have garnered increasing attention due to their high theoretical capacity, high safety, and low cost. However, their commercialization has been impeded by the rapid cycling deterioration caused by side reactions and dendrite growth on Zn anodes. The present work explores a dielectric organic−inorganic film with a hydrophobic surface to circumvent these problems and suppress dendrite growth on the zinc anode. Dielectric BaTiO 3 /P(VDF-TrFE) (BTO/PVT) coating has been demonstrated to promote uniform zinc deposition and inhibit dendrite growth. The hydrophobic surface also regulates the Zn-ion desolvation process at the interfaces and is crucial in preventing water from harming the Zn anode surface, leading to a dendrite-free surface and little formation of byproducts. The resulting BTO/PVT@Zn anode has a long lifespan of 3000 h and an average Coulombic efficiency of 99.6% at 1 mA cm −2 . In addition, the BTO/PVT@Zn||NH 4 V 4 O 10 full cell shows a good rate capability and a long cycling lifespan.

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In this paper, we disclosed the realization of a “continuous” nano‐structured alignment patterning for thin film Pancharatnam‐Berry phase (PBP) diffractive lens by the use of spatially linear polarized light converter technology. High optical quality thin liquid crystal polymer (LCP) film PBP lens with F number of 45.4 and a diffraction efficiency of 95.5%, operating in blue visible region has been demonstrated. The concave and convex polarization dependent property of the lens can be clearly observed by human eye, which is attractive in many display applications, for example, bifocal lens for eye glasses; camera zoom system; and polarization imaging.