Use of Ethylene Carbonate Free Ester Solvent Systems with Alternative Lithium Salts for Improved Low-Temperature Performance in NCM622∣∣ Graphite Li-ion Batteries

Autor:	Nuwanthi D. Rodrigo, Chamithri Jayawardana, Leah Rynearson, Enyuan Hu, Xiao-Qing Yang, Brett L. Lucht
Rok vydání:	2022
Předmět:	Renewable Energy Sustainability and the Environment Materials Chemistry Electrochemistry Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials
Zdroj:	Journal of The Electrochemical Society. 169:110504
ISSN:	1945-7111 0013-4651
Popis:	An investigation of alternative lithium salts, lithium tetrafluoroborate (LiBF4), lithium difluoro(oxalato)borate (LiDFOB) and lithium hexafluorophosphate (LiPF6), in novel ester-based (methyl acetate/fluoroethylene carbonate- MA/FEC or methyl propionate/fluoroethylene carbonate- MP/FEC) electrolyte formulations has been conducted in LiNi0.6Co0.2Mn0.2O2 (NCM622)/graphite cells to improve low temperature cycling performance of lithium ion batteries at −20 °C. Improved low temperature performance was observed with all the lithium salts in MA/FEC electrolyte while comparable room temperature (25 °C) capacities were observed with LiPF6 salt only. Detailed ex-situ analysis of surface films generated with LiBF4, LiDFOB and LiPF6 in ester-based electrolytes reveals that the solid electrolyte interphase (SEI) is predominately composed of lithium salt decompaction products and addition of 10% FEC (by volume%) may not be sufficient at forming a protective SEI.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f030e3ea5645b969851179c457e56742 https://doi.org/10.1149/1945-7111/ac9d0a Zobrazit plný text záznamu