Abstract:
The fast-growing demand for high-capacity lithium-ion batteries has spurredextensive research efforts. Developing rechargeable lithium-ion batteries with characteristics such as low cost in fabrication, flexibility in packaging, high energy density, and power density is necessary to meet the diverse requirements of applications like mobile electronics, electric vehicles, and hybrid electric vehicles. This study focuses on the impact of varying concentrations of undoped and vanadium-doped Li2FeSiO4 (LFS)on the nanosized phase purity properties. Several samples of undoped and doped Li2FeSi1-xVxO4, where x ranges from 0.05 to 0.2, were synthesized using a conventional sol-gel technique to address these objectives. Attempts were made to employ coke to create a cost-effective inert atmosphere during sintering, and starch and glucose were explored as additives to facilitate such an environment. Successful implementation of a simple and cost-effective process could pave the way for upscaling and commercializing undoped and doped Li2FeSi1-xVxO4.The theoretically calculated amounts of 5%, 10%, 15%, and 20% of vanadium (V) were introduced using NH4VO3 to obtain V-substituted Li2FeSiO4 composites. Phase identification and lattice parameters of the active materials are characterized by X-ray diffraction (XRD) using the Rietveld refinements method. Microstructural analysis using a scanning electron microscope (SEM) revealed LFS samples comprised mostly of agglomerated small particles ranging from 54 to 477 nm, although particle size increased beyond 10% V doping. SEM imagery indicated effective vanadium incorporation within the matrix. XRD analysis confirmed better phase purity when vanadium concentration (x) is 0.1. Notably, the samples exhibited additional conductive phases, including Li2SiO3, Fe2.5Li0.5O4, and V4O5. Among the evaluated composites, the 5% V-doped variant demonstrated smaller particle size (78 nm). However, 20% V-dopedLFS has lower impurity phases than other V-doped irregularly shaped Li2FeSiO4.
