Ortiz Daniel, Jiménez Gordon Isabel, Baltaze Jean-Pierre, Hernandez-Alba Oscar, Legand Solène, Dauvois Vincent, Si Larbi Gregory, Schmidhammer Uli, Marignier Jean-Louis, Martin Jean-Frédéric, Belloni Jacqueline, Mostafavi Mehran, Le Caër Sophie
Institut Rayonnement Matière de Saclay, Bât. 546, NIMBE UMR 3685 CNRS/CEA, LIONS, 91191, Gif-sur-Yvette Cedex, France.
CEA/LITEN/DEHT/SCGE, 38000, Grenoble, France.
ChemSusChem. 2015 Nov;8(21):3605-16. doi: 10.1002/cssc.201500641. Epub 2015 Jul 23.
The ageing phenomena occurring in various diethyl carbonate/LiPF6 solutions are studied using gamma and pulse radiolysis as a tool to generate similar species as the ones occurring in electrolysis of Li-ion batteries (LIBs). According to picosecond pulse radiolysis experiments, the reaction of the electron with (Li(+), PF6(-)) is ultrafast, leading to the formation of fluoride anions that can then precipitate into LiF(s). Moreover, direct radiation-matter interaction with the salt produces reactive fluorine atoms forming HF(g) and C2H5F(g). The strong Lewis acid PF5 is also formed. This species then forms various R(1)R(2)R(3) P=O molecules, where R is mainly -F, -OH, and -OC2H5. Substitution reactions take place and oligomers are slowly formed. Similar results were obtained in the ageing of an electrochemical cell filled with the same model solution. This study demonstrates that radiolysis enables a description of the reactivity in LIBs from the picosecond timescale until a few days.
利用伽马射线和脉冲辐解作为工具，研究了各种碳酸二乙酯/LiPF6溶液中出现的老化现象，以便生成与锂离子电池（LIBs）电解过程中出现的类似物种。根据皮秒脉冲辐解实验，电子与(Li(+)，PF6(-))的反应极快，导致氟阴离子形成，然后氟阴离子可沉淀为LiF(s)。此外，盐与辐射物质的直接相互作用产生反应性氟原子，形成HF(g)和C2H5F(g)。还会形成强路易斯酸PF5。该物种随后形成各种R(1)R(2)R(3)P=O分子，其中R主要为-F、-OH和-OC2H5。发生取代反应并缓慢形成低聚物。在充满相同模型溶液的电化学电池老化过程中也获得了类似结果。这项研究表明，辐解能够描述从皮秒时间尺度到几天内LIBs中的反应活性。
