TY - JOUR AU - Murmann, Patrick AU - Mönnighoff, Xaver AU - von Aspern, Natascha AU - Janssen, Pia AU - Kalinovich, Nataliya AU - Shevchuk, Michael AU - Kazakova, Olesya AU - Röschenthaler, Gerd-Volker AU - Cekic-Laskovic, Isidora AU - Winter, Martin TI - Influence of the Fluorination Degree of Organophosphates on Flammability and Electrochemical Performance in Lithium Ion Batteries: Studies on Fluorinated Compounds Deriving from Triethyl Phosphate JO - Journal of the Electrochemical Society VL - 163 IS - 5 SN - 1945-7111 CY - Pennington, NJ PB - Electrochemical Soc. M1 - FZJ-2017-07606 SP - A751 - A757 PY - 2016 AB - Three symmetric substances originating from triethyl phosphate were specifically synthesized with varying degree of fluorination at the side chain. Different concentrations of each phosphate were evaluated as co-solvent with regard to their flammability and the electrochemical cycling performance. With higher degree of fluorination and a higher amount of the phosphate in the electrolyte, the self-extinguishing time (SET), a value to determine and compare the flammability of electrolytes, could be significantly lowered to yield a non-flammable electrolyte mixture. A specifically designed SET device is introduced, which offers more accurate results due to lowered standard deviations by minimizing random and systematic errors. As the application of phosphates as co-solvents results in a trade-off in cycling performance, a thorough determination in regard to the ionic conductivity, the anodic oxidation stability and the compatibility with anode and cathode material was carried out in half- and full-cells. The manuscript strives to establish a deeper understanding of the influence that the utilization of phosphates as co-solvents entail with special focus on the fluorination degree. It could be shown that the partially fluorinated phosphate offers the best cycling results and therefore the lowest trade-off in performance, while a severe improvement in SET could be achieved compared to the reference electrolyte. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000370866700023 DO - DOI:10.1149/2.1031605jes UR - https://juser.fz-juelich.de/record/840040 ER -