Phosphorus‐functionalized graphene for power and cyclability improved lithium‐ion capacitors

Open Access

Abstract

Herein we report an easy approach for the preparation of graphene‐based materials suitable as electrodes for lithium‐ion capacitors (LICs). To the best of our knowledge, this is the first time that phosphorus‐functionalized graphene oxide (rGO800‐P) is used as negative (battery‐type) electrode in LICs technology. An activated carbon derived from the pyrolysis of graphene‐carbon composite served as positive (capacitor‐type) electrode. While phosphorus functionalization on the negative electrode enables fast Li + kinetics during insertion/extraction processes, the flat‐shaped morphology, large surface area and proper pore size distribution of the positive electrode enhance the double‐layer formation. Full LICs optimization, through oversizing the negative electrode, allows operating in the extended voltage window of 1.5‐4.5 V delivering high energy and power values (91 W h kg ‐1 AM at 145 W kg ‐1 AM and 33 W h kg ‐1 AM at 26,000 W kg ‐1 AM ) without compromising the cycling performance (76% capacitance retention after 10,000 cycles). ; The authors thank the European Union (Graphene Flagship, Core 3, Grant number 881603)