Effect of Sn on the structural, morphological and optical properties of liCoPO4

In the presented work, the influence of Sn doping on structural, morphological, and optical properties is systematically investigated. In this regard, in order to overcome such drawbacks, Sn was incorporated into the LiCoPO₄ matrix through a solid-state synthesis route by varying the Sn concentration from 0 to 8 mol%. XRD recorded the structural changes upon Sn doping, which indicated that Sn incorporation did not change the LiCoPO₄ primary orthorhombic olivine structure, though inducing minor changes in the lattice parameters due to the radius difference between Sn⁴⁺ and Co²⁺. TEM studies were performed to investigate the morphological properties. The optical properties were studied by UV–Vis spectrophotometer and showed a gradual decrease of the optical bandgap with increasing Sn content, the highest bandgap (3.94 eV) was obtained for x = 0 of Sn while the lowest value of band gap (3.64) was obtained for x = 0.08 of Sn. The refractive index decreased with an increase in the concentrations of Sn, 1.8 to 1.6 respectively. The non-linear absorption coefficient increases with Sn doping. Thus, these findings provide a new route to modify the properties of LiCoPO₄ for energy storage and also manifest Sn as a potential dopant for enhancing the performances of transition metal phosphates, particularly in various technological uses. This study therefore paves the way for further optimization of LiCoPO₄ and similar materials for high-performance batteries and other functional devices.