Perovskite oxides, as a kind of functional materials, have been widely studied in recent years due to its unique physical, chemical, and electrical properties. Here, we successfully prepared perovskite-type LaCoO₃ (LCOs) nanomaterials via an improved sol-gel method followed by calcination, and investigated the influence of calcination temperature and time on the morphology, structure, and electrochemical properties of LaCoO₃ nanomaterials. Then, based on the optimal electrochemical performance of LCO-700-4 electrode sample, the newly synthesized nanocomposites of Sr-doping (LSCO-0.2) and rGO-compounding (rGO@LCO) through rational design exhibited a 1.45-fold and 2.03-fold enhancement in its specific capacitance (specific capacity). The rGO@LCO electrode with better electrochemical performances was further explored by assembling rGO@LCO//rGO asymmetric supercapacitor system (ASS) with aqueous electrolyte. The result showed that the ASS delivers a high energy density of 17.62 W h kg⁻¹ and an excellent cyclic stability with 94.48% of initial capacitance after 10,000 cycles, which are good electrochemical performances among aqueous electrolytes for green and new efficient energy storage devices.

Aqueous zinc ion batteries are often adversely affected by the poor stability of zinc metal anodes. Persistent water‐induced side reactions and uncontrolled dendrite growth have seriously damaged the long‐term service life of aqueous zinc ion batteries. In this paper, it is reported that a zinc sulfide with optimized electron arrangement on the surface of zinc anode is used to modify the zinc anode to achieve long‐term cycle stability of zinc anode. The effective active sites of the zinc metal anode surface are first significantly improved by a simple ultrasound‐assisted etching strategy, and then the in situ zinc sulfide interface phase further guides the zinc ion deposition behavior on the surface of the zinc metal anode. The zinc sulfide protective layer well regulates the interfacial electric field and the migration of Zn²⁺, thereby significantly promoting the homogenization of zinc ion flux to achieve dendrite‐free deposition. In addition, the aqueous zinc ion full cell assembled based on ZnS@3D‐Zn anode achieves better output performance in long‐term cycles. In summary, this work sheds light on the importance of reasonable interfacial modification for the development of dendrite‐free and stable zinc anode chemistry, which opens up a new path for promoting the development of zinc‐based batteries.

In this paper, a dual-band metamaterial absorber (MMA) with wide-angle and high absorptivity is proposed. The MMA consists of two silver layers separated by a dielectric layer. Its top resonant element is constituted by two concentric ring resonators connected with four strips. Based on electromagnetic field simulation, the proposed MMA has two narrow absorption peaks with an absorption rate of 99.9% at 711 nm and 99.8% at 830 nm, and the corresponding line width of the two absorption peaks are only 9.7 and 9.8 nm. The dual-band MMA shows high absorptivity under wide incident angles. The simulated field pattern shows that dual-band perfect absorption is the combined result of the interaction of two concentric ring resonators and unit cell coupling. In addition, the hexapole plasmon mode can be observed at the outer ring at one absorption peak. The narrow plasmon resonance has a potential application in optical sensing, and can be used to measure the concentration of aqueous glucose with two frequency channels. The proposed MMA with high absorptivity is simple to manufacture, and has other potential applications, such as narrow-band filters, energy storage device, and so on.

Designing a novel, efficient, and cost-effective nanostructure with the advantage of robust morphology and outstanding conductivity is highly promising for the electrode materials of high-performance electrochemical storage device. In this paper, a series of honeycombed perovskite-type Sr-doped LaNiO₃ nanosheets with abundant porous structure were successfully synthesized by accurately controlling the Sr-doped content. The study showed that the optimal LSNO-0.4 (La_0.6Sr_0.4NiO_3-δ) electrode exhibited excellent electrochemical performance, which showed a high capacity of 115.88 mAh g⁻¹ at 0.6 A g⁻¹. Furthermore, a hybrid supercapacitor device (LSNO//AC) based on LSNO-0.4 composites and activated carbon (AC) showed a high energy density of 17.94 W h kg⁻¹, a high power density of 1600 W kg⁻¹, and an outstanding long-term stability with 104.4% capacity retention after 16,000 cycles, showing an excellent electrochemical performance and a promising application as an electrode for energy storage.