A free-standing flexible anode material for sodium storage with sandwich-structured characteristics was fabricated by modified vacuum filtration, consisting of stacked layers of Na₂Ti₃O₇ [email protected] nanotubes (NTO [email protected]) and graphene oxide. The NTO NWs have a larger specific surface area for Na⁺ insertion/extraction with shortened ion diffusion pathways, accelerating the charge transfer/collection kinetics. The added CNTs both facilitate the uniform dispersion of the nanowires and nanotubes and also contribute to the connectivity of the nanowires, improving their conductivity. More importantly, the unique sandwichlike layered-structured film not only provides large numbers of electron-transfer channels and promotes the reaction kinetics during the charging and discharging process but also ensures the structural stability of the NTO NWs and the electrode. Electrochemical measurements suggest that this rationally designed structure endows the electrode with a high specific capacity and excellent cycling performance. A satisfactory reversible capacity as high as 92.5 mA h g^–1 was achieved after 100 cycles at 2C; subsequently, the electrode also delivered 59.9 mA h g^–1 after a further 100 cycles at 5C. Furthermore, after the rate performance test, the electrode could be continuously cycled for 100 cycles at a current density of 0.2C, which demonstrated that durable cyclic capacity with a high reversible capacity of 114.1 mA h g^–1 was retained. This novel and low-cost fabrication procedure is readily scalable and provides a promising avenue for potential industrial applications.

中文翻译：

---

由Na ₂ Ti ₃ O ₇ [受电子邮件保护]和还原的氧化石墨烯组成的自由夹心结构柔性膜电极，用于高级钠离子电池

通过改进的真空过滤，制造了一种具有三明治结构特征的钠存储用自立式柔性阳极材料，该材料由Na ₂ Ti ₃ O ₇ [受电子邮件保护的]纳米管（NTO [受电子邮件保护的]）和氧化石墨烯的堆叠层组成。NTO NW具有较大的Na ⁺比表面积缩短离子扩散途径进行插入/提取，加快了电荷转移/收集动力学。添加的CNT既有利于纳米线和纳米管的均匀分散，又有助于纳米线的连通性，从而提高其导电性。更重要的是，独特的三明治状层状结构膜不仅提供了大量的电子传输通道，并在充电和放电过程中促进了反应动力学，而且还确保了NTO NW和电极的结构稳定性。电化学测量表明，这种合理设计的结构赋予电极高比容量和出色的循环性能。令人满意的可逆容量高达92.5 mA hg ^–1在2C下经过100次循环后达到 随后，在5C下再经过100个循环后，电极还提供了59.9 mA hg ^–1。此外，经过速率性能测试后，该电极可以在0.2C的电流密度下连续循环100次，这表明保留了具有114.1 mA hg ^–1的高可逆容量的持久循环容量。这种新颖且低成本的制造过程易于扩展，并为潜在的工业应用提供了有希望的途径。