Scalable waste plastic derived carbon nanosheets with high contents of inbuilt nitrogen sulfur sites for high performance potassium ion hybrid capacitors

Potassium ion hybrid capacitors KIHCs demonstrate a broad prospect as promising electrochemical energy storage devices, attributing to combination merits of batteries and supercapacitors i.e., high energy density and high power output . One pivotal task in the development of high performance KIHCs is to search for an outstanding anode that can balance the kinetics mismatch between capacitor type cathodes and battery type anodes. As known that plastics seen commonly everywhere can have a high carbon content of 85.7 wt . Herein, a large scalable carbon nanosheets NPCNs material with high contents of inbuilt nitrogen sulfur sites is manufactured through a simple synthesis technique with low cost waste plastic as precursors. The as fabricated battery type anode electrode suggests outstanding electrochemical performances owing to its expanded interlayer spacing, sufficient structural defects, functional groups, and redox active sites favorable for improving the pseudocapacitive activity and accelerating the kinetics of K storage. In particular, a capacity retention rate of 94 over 16,000 long cycling, indicating unprecedented cycle stability. Moreover, in situ Raman spectroscopy and density functional theory calculations further verify the potassium storage behavior. The as assembled KIHCs deliver a remarkable energy power density 61 Wh kg amp; 8722;1 at 36576 W kg amp; 8722;1 and ultralong cycling stability 87.0 capacity retention over 6000 cycle