Study of Pr doped nanocrystalline LiCoO2 cathode material for spintronic and energy storage applications: A theoretical and experimental analysis

Abstract

In this study, Pr³⁺ substituted LiCoO₂ lithium-rich cathode materials were prepared using the sol-gel auto-combustion technique to enhance cycling performance. LiCo_1-xPr_xO₂ samples having Pr concentrations x = 0.00–0.10 were synthesized. X-ray diffraction (XRD) showed a rhombohedral structure with space group R-3m, further verified by the Rietveld refinement. Field emission scanning electron microscopy (FESEM) revealed the presence of distinct and well-defined submicron-scale grains. FTIR spectroscopy confirmed Co–O stretching bonds within 590–560 cm⁻¹ and revealed peaks at around 560–590, 830–860, and 1320-1480 cm⁻¹, which could be attributed to the electrochemical performance of Pr-doped species. Moreover, EDX spectroscopy confirmed the typical elemental peaks of only Co, Pr, and O, confirming the required phase presence. The cyclic voltammetry showed improved reversibility and stability due to Pr doping. The first-principles computations were performed using the lattice constant extracted from XRD measurements. The pure LiCoO₂ with a semiconducting nature became half-metallic due to Pr doping (LiCo_0.84Pr_0.16O₂). The magnetic properties indicate that LiCoO₂ and LiCo_0.84Pr_0.16O₂ exhibit positive magnetic order, which shows that these are suitable candidates for spintronic applications. The pure LiCoO₂ revealed intercalation voltages of 4.10–2.73V and a theoretical capacity 40–203 mAh/g. Meanwhile, for LiCo0.84Pr0.16O2, the intercalation voltages and theoretical capacity improved to 4.42–2.85 V and 42 to 211 mAh/g, respectively. The combined experimental and theoretical study suggests that Pr-doped LiCoO₂ is suitable for spintronic applications and energy applications such as composite cathodes.