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.

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.

A combination of a triboelectric nanogenerator (TENG) and natural wood presents a sustainable approach toward a smart home due to the wood’s biodegradability, low cost, and abundant resource. Major challenges for achieving a cellulose-based TENG are the brittleness, low crystallinity, and low surface charge density. We demonstrated a facile method to process and modify natural wood to satisfy application requirements. The treated wood has both good flexibility and tensile mechanical properties. After pressing, its crystallinity also saw a big increase, with the figure almost tripled. A further surface modification was inspired by dyeing technology. The cellulose on the surface of wood was cationically modified by 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTAC) via the solution-immersion method. After modification, the surface potential increased two times compared to that of the unmodified one. Density functional theory was used to calculate the absorption energy between cellulose molecules and CHPTAC to further verify the feasibility of the chemical modification. Larger differences between the two tribo-layers in terms of the energy level produce a high electrostatic charge flow. The modified pressed wood-based TENG can generate a peak current of 9.74 μA, a voltage of 335 V, and a transferred charge density of 71.45 μC/m2 through contact electrification. A concept of a self-powered and sensing smart floor integrated with this modified cellulose-based TENG was further developed to provide real-time motion monitoring for a smart home. This work not only removes the wood brittleness but also puts forward a novel method to improve the wood surface charge density from an interdisciplinary perspective, which is crucial to facilitate the application of natural wood in the nanogenerator area.

The rapid development of the 5G communication technology requires the improvement of the thermal stability and dielectric performance of high-frequency copper clad laminates (CCL). A cyclic olefin copolymer (COC) resin was added to the original 1,2-polybutadienes (PB)/styrene ethylene butylene styrene (SEBS) binary resin system to construct a PB/SEBS/COC ternary polyolefin system with optimized dielectric properties, mechanical properties, and water absorption. Glass fiber cloths (GFCs) and SiO2 were used to fill the resin matrix so to reduce the thermal expansion coefficient (CTE) and enhance the mechanical strength of the composites. It was found that the CTE of polyolefin/GFCs/SiO2 composite laminates decreased with the increase of SiO2 loading at first, which was attributed to the strong interfacial interaction restricting the segmental motion of polymer chains between filler and matrix. It was obvious that the addition of COC and SiO2 had an effect on the porosity, as shown in the SEM graph, which influenced the dielectric loss (Df) of the composites directly. When the weight of SiO2 accounted for 40% of the total mass of the composites, the laminates exhibited the best comprehensive performance. Their CTE and Df were reduced by 63.3% and 22.0%, respectively, and their bending strength increased by 2136.1% compared with that of the substrates without COC and SiO2. These substrates have a great application prospect in the field of hydrocarbon resin-based CCL.

The Ni–Co–P@LDH nanocomposites with outstanding mass specific capacitance were electrodeposited on one finger of a conductive interdigital Au/PET substrate with FeOOH nanosheets on the other to fabricate an AMSC device.