Energetic Metal-Organic Frameworks Derived Highly Nitrogen-Doped Porous Carbon for Superior Potassium Storage.

ABSTRACT

The carbonaceous materials with low cost and high safety have been considered as promising anodes for potassium-ion batteries (PIBs). However, it is still a challenge to design a carbonaceous material with long cycle life and high rate performance due to the poor K+ reaction kinetics. Herein, this article reports a N-doped porous carbon framework (NPCF) with a high nitrogen content of 13.57 at% within high doping level of the pyrrolic N and pyridinic N, which exhibits a high reversible capacity of 327 mA h g-1 over 100 cycles at a current density of 100 mA g-1 , excellent rate capability (144 and 105 mA h g-1 at 10 and 20 A g-1 , respectively) and great cyclability of 258.9 mA h g-1 after 2000 cycles at 1 A g-1 . Such a high rate performance and excellent cycling stability anode material is seldom reported in PIBs. Density functional theory (DFT) calculations reveal that the pyrrolic and pyridinic N-doping are helpful to enhance the K adsorption ability, thereby increasing the specific capacity.