Multi-forks hierarchical porous amorphous carbon with N-Doping for high-performance potassium-ion batteries.

Graphitic carbon with high electronic conductivity has been widespreadly reported as an anode material for potassium-ion batteries (PIBs). However, it cannot accommodate more K ions and alleviate huge volume variations during cycling due to a narrow interlayer spacing of 0.335 nm, resulting in poor electrochemical behavior. Herein, by rational design, N-doping multi-forks amorphous carbon with hierarchical pores (NCTS) was successfully fabricated. The obtained NCTS exhibited enlarged interlayer spacing (0.376 nm), high specific surface area (396.6 m2 g−1), and well developed unique porous structure. These features can reduce the diffusion distance for both ions and electrons, and maintain the stability of the electrode structure. Hence, the NCTS electrode exhibits remarkable electrochemical performance with high specific capacity of 350.3 mA h g−1 at 500 mA g−1, ultra-long lifespan (over 2000 cycles at 2000 mA g−1), and outstanding rate capability (292.3 mA h g−1 at 1000 mA g−1). This work provides efficient guidance for constructing high-performance carbon anode materials to storage potassium. [ABSTRACT FROM AUTHOR]