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

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.