Self-templated anchor of FeS2 nanoparticles on porous carbon matrix as highly reversible K-storage anode

Owing to the high theoretical capacity and low cost, transition metal disulfides have been regarded as promising high-capacity anode materials for potassium-ion batteries (PIBs). However, the practical application is hindered by poor electrical conductivity and volume expansion during electrochemical cycle process, generating fast capacity decay and poor cycle stability. Herein, we propose anchoring FeS2 nanoparticles on N-doped porous carbon (FeS2@NPC) via a self-templated method. The reversible K-storage in FeS2 was guaranteed by the confinement in the porous NPC matrix which significantly enhanced the reaction kinetics via improving the electron/K+ transporting. As a result, FeS2@NPC exhibited superior-rate properties (451.6 and 331.2 mA h/g at 0.1 and 1 A/g, respectively) and long-term cycle stability (capacity attenuation is 0.055 % per cycle). These discoveries provide fundamental references for designing advanced Fe-based anodes for PIBs.