Phase transformation and electronic structure modulation of 1T-MoS2 with electronegative non-metal doping as anode material for enhanced potassium-ion battery

Abstract

The scarcity and high cost of lithium resources drive the search for sustainable alternatives, positioning potassium-ion batteries (KIBs) as promising energy storage solutions due to the natural abundance and advantageous electrochemical properties of the potassium. This study investigates the enhancement of KIB anodes through phase transformation and electronic structure engineering of monolayer 1T-MoS2, achieved via doping with highly electronegative non-metal elements: carbon (C), nitrogen (N), oxygen (O), and fluorine (F). Density functional theory (DFT) simulations reveal that electronegative atom doping enhances phase stability, structural robustness, and thermal resilience, which are key properties for high-performance KIB anodes. Among the doped configurations, F and N-doped 1T-MoS2 (MoS2-F and MoS2-N) exhibit superior electrochemical performance, showing optimal adsorption energies and significantly improved electronic conductivity, attributable to favorable charge redistribution and increased active potassium adsorption sites. Specifically, MoS2-F and MoS2-N achieve the highest specific capacities of 339.65 and 339.17 mAh/g, respectively, while maintaining stability within an ideal open circuit voltage range, outperforming undoped MoS2. This work underscores the potential of electronegative atom doping in 1T-MoS2 to enable sustainable, high-capacity energy storage solutions, offering key advancements in the electrochemical and structural properties of KIB anodes.