Influence of the Fluorination Degree of Organophosphates on Flammability and Electrochemical Performance in Lithium Ion Batteries: Studies on Fluorinated Compounds Deriving from Triethyl Phosphate
Influence of the Fluorination Degree of Organophosphates on Flammability and Electrochemical Performance in Lithium Ion Batteries: Studies on Fluorinated Compounds Deriving from Triethyl Phosphate
复制标题
DOI：
10.1149/2.1031605jes
复制
发表时间：
2016
影响因子：
3.9
通讯作者：
P. Murmann;Xaver Mönnighoff;N. Aspern;Pia Janssen;N. Kalinovich;M. Shevchuk;O. Kazakova;G. Röschenthal
中科院分区：
文献类型：
--
作者：
P. Murmann;Xaver Mönnighoff;N. Aspern;Pia Janssen;N. Kalinovich;M. Shevchuk;O. Kazakova;G. Röschenthal
三个对称的物质来源于磷酸三乙酯，专门合成了不同程度的侧链取代。评价了不同浓度的每种磷酸盐作为共溶剂的可燃性和电化学循环性能。在电解质中具有更高的溶解度和更高量的磷酸盐的情况下，自熄时间（SET）（用于确定和比较电解质的可燃性的值）可以显著降低以产生不可燃的电解质混合物。介绍了一种专门设计的SET器件，它通过最小化随机误差和系统误差来降低标准差，从而提供更准确的结果。由于磷酸盐作为共溶剂的应用导致循环性能的折衷，因此在半电池和全电池中进行了关于离子电导率、阳极氧化稳定性以及与阳极和阴极材料的相容性的彻底测定。该手稿致力于建立一个更深入的理解的影响，利用磷酸盐作为共溶剂，特别关注的程度。可以表明，部分氟化的磷酸盐提供了最好的循环结果，因此在性能上的折衷最低，同时与参比电解质相比，可以实现SET的严重改善。
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.