Details

Autor(en) / Beteiligte

• Zhong, Yun‐lei
• Dai, Wen‐xue
• Liu, Dan
• Wang, Wei
• Wang, Li‐tong
• Xie, Jun‐Peng
• Li, Rong
• Yuan, Qing‐ling
• Hong, Guo

Titel

Nitrogen and Fluorine Dual Doping of Soft Carbon Nanofibers as Advanced Anode for Potassium Ion Batteries

Ist Teil von

• Small (Weinheim an der Bergstrasse, Germany), 2021-10, Vol.17 (43), p.e2101576-n/a

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2021

Quelle

Wiley Online Library All Journals

Beschreibungen/Notizen

• Potassium‐ion batteries (PIBs) are recognized as promising alternatives for lithium‐ion batteries as the next‐generation energy storage systems. However, the larger radius of K+ hinders the K+ insertion into the conventional carbon electrode and results in sluggish potassiation kinetics and poor cycling stability. Here, nitrogen and fluorine dual doping of soft carbon nanotubes (NFSC) anode are synthesized in one pot, achieving extraordinary electrochemical performance for PIBs. It is demonstrated that NFSC with a doping dose of 5.6 at% nitrogen and 1.3 at% fluorine together exhibits the highest reversible capacity of 238 mAh g−1 at 0.2 A g−1 and cycling stability of 186 mAh g−1 after 1000 cycles at 1 A g−1. The extraordinary electrochemical performance can be attributed to the hollow structure, expanded interlayer distance, nitrogen and fluorine dual doping, and the binding ability of abundant defect sites. Moreover, density functional theory shows that the extra fluorine modification can dramatically enhance the conventional nitrogen doping effect and reduces the formation energy which makes a great contribution to the improvement of electrical conduction and K‐ions insert. This work may promote the development of low‐cost and sustainable carbon‐based materials for PIBs and other advanced energy storage devices. The nitrogen and fluorine dual‐doped soft carbon fiber serves as the advanced anode for potassium ion battery. The dual‐doping effect is realized by locking the fluorine and nitrogen sources in the polypyrrole fiber cage which boosts the high conductivity, outstanding rate performance, and cycling stability.