Qilong Hao,Jing Zhao,Qing Wen,Jinling Yin,Guiling Wang
Sodium metal is considered a potential candidate for the anode in next-generation cost-effective and high-energy-density metal batteries. However, its practical application in ether-based electrolytes is severely hindered by the uncontrolled proliferation of sodium dendrites and the instability of the solid electrolyte interphase (SEI) layer. To address these challenges, we developed a lightweight, multifunctional separator using electrospinning technology. This separator, composed of a polymer-metal-organic framework composite (PAN/ZIF-67), offers a novel alternative to conventional bulky glass fiber separators. The PAN/ZIF-67 separator features a unique ordered structure and open active metal sites, which significantly enhance electrolyte wettability and promote anion adsorption, effectively guiding the uniform deposition of Na + . Experimental results confirmed its superior electrochemical performance, including low polarization voltage and high cycling stability, under standard ether-based electrolyte conditions without additives. In symmetric Na || Na cells equipped with the PAN/ZIF-67 separator, exceptional cycling stability was achieved, with a low polarization voltage of ∼12 mV at 1 mA cm −2 sustained over 1000 h and ∼66 mV at 5 mA cm −2 for over 500 h. In a full cell with a Na₃V₂(PO₄)₃ cathode and Na anode, the separator demonstrated excellent rate capability and cycling stability, maintaining a capacity retention of 72.4 % after 800 cycles at 5C. This work offers a possible solution to address critical issues in sodium metal batteries and represents a notable advancement toward their practical applications.
Zhao Meng,Haibo Yang,Yongzhen Ma,Yan Cheng,Yanlong Ma,Binglong Zheng,Hongwei Zhou,Ying Lin
In increasingly complex electromagnetic environments, developing high-performance and dynamically tunable electromagnetic wave (EMW) absorption materials is essential. This study designed a pressure-responsive TiO2/CNFs@Co/C elastic aerogel for efficient EMW absorption. A 3D interpenetrating structure consisting of Ti3C2Tx MXene-derived TiO2 nanosheets, magnetic Co/C frameworks, and carbon nanofibers was constructed via electrospinning combined with in situ synthesis. This 3D interpenetrating structure constructs abundant heterogeneous interfaces, thereby enhancing interfacial polarization. The results demonstrate that the composite achieves an exceptionally broad effective absorption bandwidth (EAB) of 8.17 GHz at a thickness of 2.7 mm, with only 10 wt% filler loading. Additionally, the composite exhibits strong environmental tolerance, including hydrophobicity, stretchability, and thermal insulation. Notably, the alginate-induced elastic aerogels enable dynamic tuning from 6.4 to 18 GHz under compressive strains of 0% to 66%. This work designs dynamically tunable, high-performance EMW absorbers through component optimization and interface engineering, providing a promising strategy for the preparation of next-generation multifunctional intelligent EMW absorbers.
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