A novel 1D van der Waals V2PSxSe10−x (x = 7–10) anode for enhanced electrochemical kinetics and high-rate performance via Se alloying in lithium-ion batteries

Abstract

This study modifies the novel one-dimensional van der Waals material V₂PS₁₀ by alloying it with selenium (Se) at varying ratios, enhancing its electronic conductivity and optimizing charge distribution. These improvements reduce polarization and significantly enhance its electrochemical performance. V₂PS_xSe_10−x (x = 5–10) series materials were synthesized, and those with x = 7–10 were measured. The results showed that the V₂PS_xSe_10−x (x = 7–10) series achieved capacities close to theoretical values at 0.1 A g⁻¹, and the alloyed V₂PS_xSe_10−x (x = 7–9) exhibited excellent rate performance and long-term cycling stability under high-rate conditions. Among them, V₂PS₉Se retained 83% of its capacity after 400 cycles at 1 A g⁻¹, highlighting its potential as a promising anode material for lithium-ion batteries (LIBs). Electrochemical behavior and kinetic mechanisms of pristine V₂PS₁₀ and alloyed V₂PS₉Se were investigated. Density functional theory (DFT) calculations comparing charge density and charge density difference revealed the effects of Se alloying on the performance of V₂PS₁₀. Additionally, phase transitions and morphological changes during the lithiation/de-lithiation processes were studied, providing new strategies and theoretical guidance for designing high-performance LIB anode materials.