Thermal and electrochemical properties of PEO-LiTFSI-Pyr 14TFSI-based composite cathodes, incorporating 4 V-class cathode active materials

TitleThermal and electrochemical properties of PEO-LiTFSI-Pyr 14TFSI-based composite cathodes, incorporating 4 V-class cathode active materials
Publication TypeArticolo su Rivista peer-reviewed
Year of Publication2014
AuthorsWetjen, M., Kim G.-T., Joost M., Appetecchi Giovanni Battista, Winter M., and Passerini S.
JournalJournal of Power Sources
Volume246
Pagination846-857
ISSN03787753
KeywordsAluminum, Bis(trifluoromethane sulfonyl)imide, Cathode active material, Cathodes, cobalt, Composite cathode, Degradation, Electrochemical performance, Electrochemical properties, Electrolytes, Interfaces (materials), Interfacial resistances, Ionic liquids, Lithium, Lithium metal polymer batteries, Manganese, Mechanical and thermal properties, Nbutyl-n-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, Nickel, Polyethylene oxides
Abstract

Poly(ethylene oxide)-lithium bis(trifluoromethanesulfonyl)imide N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PEO-LiTFSI-Pyr14TFSI)-based 4 V-class composite cathodes, incorporating either Li(Ni1/3Co1/3Mn1/3)O 2 or Li(Ni0.8Co0.15Al0.05)O 2 were prepared by a hot-pressing process and successively investigated in terms of their morphological, thermal, and electrochemical properties. Thereby, excellent mechanical and thermal properties could be demonstrated for all composite cathodes. The electrochemical performance of truly dry all-solid-state Li/P(EO)10LiTFSI-(Pyr14TFSI) 2/composite cathode batteries at temperatures as low as 40 C revealed high delivered capacities. However, in comparison with LiFePO4, the 4 V-class composite cathodes also indicated much lower capacity retention. In-depth investigations on the interfacial properties of Li(Ni 0.8Co0.15Al0.05)O2 composite cathodes revealed a strong dependence on the anodic cut-off potential and the presence of current flow through the cell, whereby different degradation mechanisms could be characterized upon cycling, according to which the finite growth of a surface films at both electrode/polymer electrolyte interfaces inhibited continuous decomposition of the polymer electrolyte even at potentials as high as 4.3 V. Moreover, the presence of Pyr14TFSI in the 4 V-class composite cathodes sustainably reduced the cathode interfacial resistance and presumably diminished the corrosion of the aluminum current collector. © 2013 Elsevier B.V. All rights reserved.

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URLhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-84883776724&doi=10.1016%2fj.jpowsour.2013.08.037&partnerID=40&md5=872a56cb28489ce03c536e4291ca7d0c
DOI10.1016/j.jpowsour.2013.08.037