Hierarchical porous carbon nanofibers with enhanced capacitive behavior as a flexible self-supporting anode for boosting potassium storage

• Published in: Journal of power sources 2022-03, Vol.523, p.231043, Article 231043
• Main Authors: Sun, Huilan, Zhu, Weiqi, Yuan, Fei, Zhang, Di, Li, Zhaojin, Wang, Qiujun, Li, Wen, Wang, Huan, Wang, Bo
• Format: Article
• Language: English
• Subjects: Anode; Capacitive behavior; Carbon fiber; One-dimensional nanostructure; Potassium-ion battery
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2022.231043

Carbonaceous materials with various morphologies and structures have been widely investigated as anode for potassium-ion batteries (PIBs), due to their low cost, nontoxicity, and high conductivity. However, there is still sluggish bulk diffusion in most carbon electrodes, which cannot well meet ever-increasing requirements for high power density. Herein, hierarchical porous one-dimensional carbon nanofibers (HPCNF-5) are successfully fabricated, in which one-dimensional (1D) conductivity nanostructure can facilitate electrons transfer. While the in-situ N-doping and suitable micro/mesopores configurations are beneficial for promoting surface-induced capacitive behaviors. Also, the resulting HPCNF-5 has excellent mechanical flexibility, indicating it can be directly used as a self-supporting electrode, thus endowing decreased overall battery weight and promoting reaction reversibility. These prominent structure advantages give HPCNF-5 electrode a fast ions/electrons diffusion capability, thus realizing superior rate property at a high current density of 2 A g−1 (204.6 mAh g−1) and excellent cyclability (with a capacity retention of 88% after 2000 cycles). Therefore, the findings demonstrate the comprehensive merits by combining 1D conductivity nanostructure, N-doping, hierarchical porous, and flexible self-supporting in one material, contributing to offering reference for constructing other advanced carbon materials. •Hierarchical porous one-dimensional carbon nanofibers were successfully fabricated.•The obtained product had high conductivity and improved capacitive behaviors.•Excellent rate capability especially at a high current density was achieved.