Nitrogen containing organics: A promising high capacity anode for potassium ion batteries

Recently, potassium-ion battery (PIB) has attracted growing attention as an alternative material for lithium-ion battery (LIB). However, due to the large size of potassium ions, the exploration of novel anode materials is still an open issue. Based on first-principles calculations, we systematically investigated the intercalation of potassium ions into three nitrogen containing organics, as anode materials for PIBs. The stable K-intercalated structures, formation energies, and theoretical specific capacities as well as voltage steps have been analyzed. Without obvious change of inner structure in organic molecule, the nitrogen containing anode can have a high theoretical specific capacity of over 1400 mAh/g. Moreover, the three electrode materials have a good rate performance in electronic conductivity and ion conductivity, with diffusion barriers lower than 0.25 eV. The remarkable electrochemical performance of these organics shows that they are promising PIB anodes.