Flexible Carbon Nanofibrous Membranes with Adjustable Hierarchical Porous Structure as High‐Capacity Anodes for Sodium‐Ion Batteries
Qi Su, Siyuan Zeng, Mi Tang, Zijian Zheng, Zhengbang Wang
Abstract
Preparation of porous carbon nanofibrous membranes with excellent flexibilities and high Na ion storage capabilities to satisfy the demand of wearable energy storage devices remains challenging. Herein, a continuous and flexible porous carbon nanofibrous membrane is developed as anode material for sodium‐ion batteries by electrospinning a mixture of polyacrylonitrile (PAN) and ultrafine zeolitic imidazolate framework (ZIF‐8) nanoparticles, followed by carbonization at 1200 °C. The intrinsic porous crystal structure of ZIF‐8 and their decomposition/volatilization at high temperature assist the generation of hierarchical micro‐meso pores that are homogeneously dispersed along the nanofibers, resulting in the good flexibility and excellent Na ion storage performance. Through controlling the ZIF‐8 content at 45%, the flexible anode enables a superior Na storage capacity of 418 mA h g −1 at 0.1 A g −1 with a remarkable plateau capacity of 278 mA h g −1 . The superhigh plateau capacity could be credited to the large amounts of isolated closed micro‐meso pores, implying an adsorption‐filling sodium‐ion storage mechanism. These findings provide some inspiration for the design and construction of advanced porous carbon anode materials for flexible sodium‐ion batteries.