NIMSAWARD2025-abstracts

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P1-441Co-sintering Reaction Analysis of Cathode Materials and Solid Electrolytes Studied by Experimental and Computational MethodsKey Words: All-solid-state Li-ion Batteries, Co-sintering, XAFS, XRD, TEMThe formation of a highly ion-conducting interface between oxide-based solid electrolytes and electrodes is a challenge for constructing ASSLIBs. Co-sintering at high temperatures is a widely used method but often results in undesired side reactions which cause the decomposition of substances and the formation of resistive interlayers. Phase transitions of high temperature speciesSecond and third most stable phasesLack of the target structure in the databaseConclusionCo-sintering of LCO/LATP compositesCo-sintering of LCP/LATP compositesDatabaseInverse analysisFutureIntroductionA comprehensive analysis was performed on the reaction products formed during co-sintering. The phases identified experimentally were compared with the thermodynamically stable phases predicted by thermodynamic calculations. The underlying factors responsible for the observed discrepancies between the experimental results and theoretical predictions were thoroughly investigated.Theme underDiscussionFumihiko Ichihara, Kodai Niitsu, Kazutaka Mitsuishi Machiko Ode, Shogo MiyoshiTakuya Masuda E-mail：： MASUDA.Takuya@nims.go.jpPPhhyyss.. CChheemm.. CChheemm.. PPhhyyss.., 24 (2022) 25878. JJ.. PPhhyyss.. CChheemm.. CC,, 129 (2025) 12738.LCO : LATP = 3 : 7LCO : LATP = 5 : 5LCO : LATP = 7 : 3Experimental ResultsThermodynamic Calculations CoTiO3 (-1262.6 kJ) ＋TiO2(-992.1 kJ) ⇔CoTi2O5(-2263.0 kJ)Li3PO4(-1262.6 kJ) + 3Co2TiO4(-1496.2 kJ×3) ⇔LiCoPO4(-1639.8 kJ) + Li2CoTi3O8(-3984.2 kJ) + 4CoO (-266.8 kJ ×4)Phase transition of high-temp. species CoO to Co3O4JJ.. PPhhyyss.. CChheemm.. CC,, 127 (2023) 15043.LCP : LATP = 5 : 5102030405060Intensity / a.u.2θ / degreeLiCoPO4 (ICSD No. 87422)LATP (ICSD No. 141519)Before sinteringAfter sintering at 800°CAfter sintering at 500°CAfter sintering at 700°CAfter sintering at 600°C49504960497049804990500050105020Noemalized AbsorptionPhoton Energy / eVRT500°C600°C700°C800°C770077107720773077407750Noemalized AbsorptionPhoton Energy / eVRT700°C500°C800°C600°C497049804990500050105020-0.05-0.04-0.03-0.02-0.010.000.010.020.030.040.05Difference of Noemalized AbsorptionPhoton Energy / eV 500°C-RT 600°C-RT 700°C-RT 800°C-RT