Radiolysis as a solution for accelerated ageing studies of electrolytes in Lithium-ion batteries

Daniel Ortiz (1) , Vincent Steinmetz (2) , Delphine Durand (3) , Solène Legand (3) , Vincent Dauvois (3) , Philippe Maitre (2) , Sophie Le Caër (1)

1 LIONS - Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire
2 LCPO - Laboratoire de Chimie Physique D'Orsay
3 SECR - Service d'Etudes du Comportement des Radionucléides

Diethyl carbonate and dimethyl carbonate are prototype examples of eco-friendly solvents used in lithium-ion batteries. Nevertheless, their degradation products affect both the battery performance and its safety. Therefore, it is of paramount importance to understand the reaction mechanisms involved in the ageing processes. Among those, redox processes are likely to play a critical role. Here we show that radiolysis is an ideal tool to generate the electrolytes degradation products. The major gases detected after irradiation (H 2 , CH 4 , C 2 H 6 , CO and CO 2) are identified and quantified. Moreover, the chemical compounds formed in the liquid phase are characterized by different mass spectrometry techniques. Reaction mechanisms are then proposed. The detected products are consistent with those of the cycling of Li-based cells. This demonstrates that radiolysis is a versatile and very helpful tool to better understand the phenomena occurring in lithium-ion batteries.

Domaines: Matériaux

Daniel Ortiz, Vincent Steinmetz, Delphine Durand, Solène Legand, Vincent Dauvois, et al.. Radiolysis as a solution for accelerated ageing studies of electrolytes in Lithium-ion batteries. Nature Communications, 2015, 6, pp.6950. ⟨10.1038/ncomms7950⟩. ⟨hal-01228649⟩