Bak, Seong-Min Nam, Kyung-Wan Chang, Wonyoung Yu, Xiqian Hu, Enyuan Hwang, Sooyeon Stach, Eric A. Kim, Kwang-Bum Chung, Kyung Yoon Yang, Xiao-Qing 2024-01-20T13:01:45Z 2024-01-20T13:01:45Z 2021-09-01 2013-02-12 0897-4756 https://pubs.kist.re.kr/handle/201004/128357 In this work, we present results from the application of a new in situ technique that combines time-resolved synchrotron X-ray diffraction and mass spectroscopy. We exploit this approach to provide direct correlation between structural changes and the evolution of gas that occurs during the thermal decomposition of (over)charged cathode materials used in lithium-ion batteries. Results from charged LixNi0.8Co0.15Al0.05O2 cathode materials indicate that the, evolution of both O-2 and CO2 gases are strongly related to phase transitions that occur during thermal decomposition, specifically from the layered structure (space group R (3) over barm) to the disordered spinel structure (Fd (3) over barm), and finally to the rock-salt structure (Fm (3) over barm). The state of charge also significantly affects both the structural changes and the evolution of oxygen as the temperature increases: the more extensive the charge, the lower the temperature of the phase transitions and the larger the oxygen release. Ex situ X-ray absorption spectroscopy (XAS) and in situ transmission electron microscopy (TEM) are also utilized to investigate the local structural and valence state changes in Ni and Co ions, and to characterize microscopic morphology changes. The combination of these advanced tools provides a unique approach to study fundamental aspects of the dynamic physical and chemical changes that occur during thermal decomposition of charged cathode materials in a systematic way. English AMER CHEMICAL SOC LI-ION BATTERIES TIME-RESOLVED XRD LIBOB EC/DEC ELECTROLYTES NICKEL-OXIDE DERIVATIVES X-RAY-DIFFRACTION POLY(VINYLIDENE FLUORIDE) MASS-SPECTROMETRY IN-SITU STABILITY LI(NI0.8CO0.15AL0.05)O-2 Correlating Structural Changes and Gas Evolution during the Thermal Decomposition of Charged LixNi0.8Co0.15Al0.05O2 Cathode Materials Article 10.1021/cm303096e 1 CHEMISTRY OF MATERIALS, v.25, no.3, pp.337 - 351 CHEMISTRY OF MATERIALS 25 3 337 351 scie scopus 000315018500010 2-s2.0-84873626376 Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science Article LI-ION BATTERIES TIME-RESOLVED XRD LIBOB EC/DEC ELECTROLYTES NICKEL-OXIDE DERIVATIVES X-RAY-DIFFRACTION POLY(VINYLIDENE FLUORIDE) MASS-SPECTROMETRY IN-SITU STABILITY LI(NI0.8CO0.15AL0.05)O-2 energy storage safety abuse tolerance X-ray absorption spectroscopy transmission electron microscopy