Dual nitrogen-doped MoS₂/graphene heterostructure for ultrafast potassium-ion storage: A combined computational and experimental study

The development of advanced anode materials for potassium-ion batteries (PIBs) significantly constrained by volume expansion and interfacial resistance during potassium ion (K⁺) intercalation. Comprehensive density functional theory (DFT) testing of nitrogen (N), Phosphorus (P), and Aluminum (Al) doped MoS₂/graphene systems conducted, we identified nitrogen-doped MoS₂/graphene (N-MoS₂@NG) as the optimal candidate, eliminating MoS₂bandgap (1.67 eV → 0 eV) exhibiting superior electronic properties as evidenced by electronic localization function (ELF), density of states (DOS), and band structure calculations. Implementing these theoretical predictions, we fabricated N-MoS₂@NG conductive heterostructure via self-propagating combustion synthesis (SPCS). Electrochemical testing demonstrates exceptional performance, including a high reversible capacity (310 mAh g⁻¹), outstanding rate capability (288 mAh g⁻¹at 1 A g⁻¹after 100 cycles), superior cycling stability (81.6 % retention after 1000 cycles with columbic efficiency 99.8 %), achieving a 61.3 % reduction in interfacial resistance (12 Ω vs. 31 Ω for undoped MoS₂@G), supported by a predominantly pseudocapacitive storage mechanism (81 % contribution at 0.6 mV s⁻¹) that enables ultrafast potassium-ion storage. This work successfully bridges computational design with experimental realization, presenting N-MoS₂@NG as a high-performance anode solution that addresses the fundamental challenges in PIB technology through synergistic materials engineering.