Microstructure and electrical properties of spark plasma sintered Li1+xCexZr2-x(PO4)3 as solid electrolyte for lithium-ion batteries en en In this study, the microstructural and electrical characteristics of spark plasma sintered Li1+xCexZr2-x(PO4)3 solid electrolytes were investigated, specifically underlining the impacts of Ce substitution on their performance as Li-ion battery electrolytes. Samples with varying amounts of Ce (x = 0.1, 0.2, and 0.3) were synthesized via the conventional solid-state reaction method. The densified samples were systematically characterized using advanced techniques, including X-ray diffraction (XRD) for phase detection, field emission scanning electron microscopy (FESEM) for microstructural analysis, and energy-dispersive X-ray spectroscopy (EDS) for elemental analysis. A significant improvement in densification and a subsequent reduction in porosity were observed in the SPSed samples, with the LZPC3 sample achieving a high relative density of 92.08%. The XRD and EDS analyses confirmed the formation of the main NASICON phase along with a Ce-rich secondary phase that segregated during the SPS process. Crucially, the Nyquist plot analysis revealed that Ce substitution did not hinder Li+ ion transport; instead, the overall ionic conductivity of the LZPC3 sample was substantially enhanced compared to the undoped LZP sample. This positive outcome is attributed to the aliovalent substitution (Ce3+ for Zr4+), effectively increasing the concentration of mobile charge carriers. The high densification and significant enhancement in ionic conductivity achieved through Ce doping and SPS processing demonstrate the potential of this composition for advanced solid-state electrolyte applications. 248 258 Zahra Khakpour Ceramic Department, Materials and Energy Research Center (MERC), Karaj Iran z.khakpour@merc.ac.ir Saeed Sedaghat Ceramic Department, Materials and Energy Research Center (MERC), Karaj Iran Mohammad Farvizi Department of Materials Engineering, Faculty of Mechanical Engineering University of Tabriz, Tabriz 51666-16471 Iran Nima Naderi Department of Semiconductors, Materials and Energy Research Center (MERC), Karaj Iran Abouzar Massoudi Department of Semiconductors, Materials and Energy Research Center (MERC), Karaj Iran Li1+xCexZr2-x(PO4)3 Ionic conductivity Spark plasma sintering Cerium substitution Microstructural analysis Solid electrolyte Vol 5 No 3 Paper 7.pdf [1] R. Tao, B. Steinhoff, K. Uzun, B. La Riviere, K. 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