Yu Tiantian, Lin Bo, Li Qiufeng, Wang Xiaoguang, Qu Weili, Zhang Sen, Deng Chao
Key Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang, China.
Key Laboratory of Superlight Material and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, Heilongjiang, China.
Phys Chem Chem Phys. 2016 Sep 29;18(38):26933-26941. doi: 10.1039/c6cp04958c.
The design of a freestanding electrode is the key to the development of energy storage devices with superior electrochemical performance and mechanical durability. Herein, we propose a highly-scalable strategy for the facile synthesis of a freestanding alluaudite NaFe(SO)@porous carbon-nanofiber hybrid film, which is used as a self-supported and flexible electrode for sodium ion batteries. By the combined use of electrospinning and electrospraying, the freestanding hybrid film is constructed in the form of sulfate nanoparticles enwrapped in highly porous graphitic-like carbon-nanofibers. The multimodal porous architecture of the freestanding hybrid film ensures its superiority in mechanical flexibility and structural stability during repeated electrochemical processes, which meets the long-standing challenge of practical application. Moreover, both the highly conductive and porous framework and the nanoscale particles are favorable for promoting fast electron/ion transport capability. Compared with other carbon based supports such as graphene (GA), carbon nanotubes (CNTs) and active carbons (ACs), the flexible carbon nanofiber shows better interaction with electrochemical active materials and superior electrochemical properties. It retains over 95% of the capacity after five hundred cycles at alternate rates of 40C and 5C, which demonstrates the superior ultralong time and high-rate cycling capability. Therefore, the present work provides a facile and highly scalable strategy for the design and fabrication of high-performance freestanding sulfate cathodes for advanced sodium ion batteries.
独立电极的设计是开发具有卓越电化学性能和机械耐久性的储能装置的关键。在此，我们提出了一种高度可扩展的策略，用于简便合成独立的钠铁矾NaFe(SO)@多孔碳纳米纤维混合薄膜，该薄膜用作钠离子电池的自支撑且柔性的电极。通过结合静电纺丝和静电喷雾，以包裹在高度多孔的类石墨碳纳米纤维中的硫酸盐纳米颗粒的形式构建独立混合薄膜。独立混合薄膜的多模态多孔结构确保了其在重复电化学过程中的机械柔韧性和结构稳定性方面的优越性，这满足了实际应用中长期存在的挑战。此外，高导电性和多孔框架以及纳米级颗粒都有利于促进快速的电子/离子传输能力。与其他碳基载体如石墨烯（GA）、碳纳米管（CNTs）和活性炭（ACs）相比，柔性碳纳米纤维与电化学活性材料表现出更好的相互作用和卓越的电化学性能。在40C和5C的交替速率下循环五百次后，它保留了超过95%的容量，这证明了其卓越的超长寿命和高倍率循环能力。因此，本工作为先进钠离子电池的高性能独立硫酸盐阴极的设计和制造提供了一种简便且高度可扩展的策略。
