| From simple alkaline oxides to high entropy transition metals oxides - applications in electrochemical energy storage Janina Molenda1; 1AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY, KRAKóW, Kraków, Poland; PAPER: 139/AdvancedMaterials/Regular (Oral) SCHEDULED: 17:10/Tue. 29 Nov. 2022/Saitong ABSTRACT: The author of this work based on her own investigations of LixMO2 cathode materials (M=Ni, Co, Mn, Cu) has demonstrated that the chemical disorder influenced on electronic structure of these materials plays an important role in the electrochemical intercalation process [1]. The paper reveals correlation between chemical disorder, crystal and electronic structure, transport and electrochemical properties of layered LixCoO2, LixNi1-y-zCoyCuzMn0.1O2 and NaxCoO2-y cathode materials and explains of apparently different character of the discharge/charge curve in those systems. Comprehensive experimental studies of physicochemical properties of LixNi1-y-zCoyCuzMn0.1O2, NaxCoO2-y and NaNi1/5Co1/5Fe1/5Mn1/5Ti1/5O2 cathode materials (XRD, electrical conductivity, thermoelectric power) are supported by electronic structure calculations performed using the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) to account for chemical disorder. It is found that even small O defects (~1%) may significantly modify DOS characteristics via formation of extra broad peaks inside the former gap leading to its substantial reduction. Moreover, these DOS peaks of “defects” strongly evolve with Li and Na contents, actually leading to the overall reduction of the gap and even to the pseudogap. The battery on the base of the developed high entropy oxides NaNi1/5Co1/5Fe1/5Mn1/5Ti1/5O2 cathode materials are characterized by high potential, high capacity and high rate capability guaranteeing high energy and power densities. Acknowledgements This work was funded by the National Science Centre Poland (NCN) under the “OPUS 17 programme on the basis of the decision number 2019/33/B/ST8/00196. References: J.Molenda, A.Milewska, W. Zajac, M.Rybski, J. Tobola, Phys. Chem. Phys. Chem. 19, (2017) 5697 |
