Effective enhancement of the electrochemical performance of layered LiCoO₂ cathode materials via WS₂ doping

Raising the operating voltage of cathode materials is essential for the development of high-energy-density lithium-ion batteries. Nevertheless, structural collapse of layered cathodes under high voltage has long impeded their practical deployment at elevated potentials. In this study, WS₂ is doped into lithium cobalt oxide (LiCoO₂) to compensate the charge deficit after Li⁺ extraction and to enlarge the interlayer spacing, thereby enhancing the structural stability of LiCoO₂ at high voltage. X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) confirm an expanded (003) interplanar distance and homogeneous incorporation of W and S into the LiCoO₂ lattice, which effectively reduces electrode interface impedance and restricts particle cracking during cycling. Electrochemical evaluation shows that 1.0 wt % WS₂-doped LiCoO₂ delivers a specific capacity of 205.1 mAh g⁻¹ at 0.1 C and 4.5 V with an initial Coulombic efficiency of 93.6%. After 200 cycles at 1 C, the reversible capacity remains 145 mAh g⁻¹, clearly outperforming pristine LCO.