Nitrogen and Phosphorus Codoped Vertical Graphene/Carbon Cloth as a Binder‐Free Anode for Flexible Advanced Potassium Ion Full Batteries

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 15; no. 23; pp. e1901285 - n/a
• Main Authors: Qiu, Wenda, Xiao, Hongbing, Li, Yu, Lu, Xihong, Tong, Yexiang
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.06.2019
• Subjects: Anodes; binder free; Carbon; Cloth; codoping; Cycles; Electrochemistry; Electronic devices; Flux density; full cells; Graphene; High voltages; Interlayers; Lithium; Lithium-ion batteries; Nanotechnology; Nitrogen; Phosphorus; Pigments; Potassium; potassium ion batteries; Power supplies; Rechargeable batteries; Structural stability; vertical graphene; vertical graphene; binder free; codoping; potassium ion batteries; full cells
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201901285

With the fast development in flexible electronic technology, power supply devices with high performance, low‐cost, and flexibility are becoming more and more important. Potassium ion batteries (KIBs) have a brilliant prospect for applications benefiting from high voltage, lost cost, as well as similar electrochemistry to lithium ion batteries (LIBs). Although carbon materials have been studied as KIBs anodes, their rate capability and cycling stability are still unsatisfactory due to the large‐size potassium ions. Herein, a nitrogen (N) and phosphorus (P) dual‐doped vertical graphene (N, P‐VG) uniformly grown on carbon cloth (N, P‐VG@CC) is reported as a binder‐free anode for flexible KIBs. With the combined advantages of rich active sites, highly accessible surface, highly conductive network, larger interlayer spacing as well as robust structural stability, this binder‐free N, P‐VG@CC anode exhibits high capacity (344.3 mAh g−1), excellent rate capability (2000 mA g−1; 46.5% capacity retention), and prominent long‐term cycling stability (1000 cycles; 82% capacity retention), outperforming most of the recently reported carbonaceous anodes. Moreover, a potassium ion full cell is successfully assembled on the basis of potassium Prussian blue (KPB)//N, P‐VG@CC, exhibiting a large energy density of 232.5 Wh kg−1 and outstanding cycle stability. A nitrogen and phosphorus dual‐doped vertical graphene uniformly grown on carbon cloth is reported as a binder‐free anode for flexible potassium ion batteries. Benefiting from the large surface, sufficient active sites, enhanced electronic and ionic conductivities, and increased interlayer distance, the material performs excellently in rate performance and cycling durability. Moreover, a flexible potassium ion full cell is assembled and exhibits exceptional electrochemical performance.