On the electrochemical and thermal behavior of lithium bis(oxalato)borate (LiBOB) solutions

In recent years, lithium bis(oxalato)borate, LiB(C2O4)2 (LiBOB) has been proposed as an alternative salt to the commonly used electrolyte, LiPF6. There is evidence of the enhanced stability of Li-ion battery electrodes in solutions of this salt, due to a unique surface chemistry developed in LiBOB solutions. The present study is aimed at further exploring the electrochemical and thermal properties of LiBOB solutions in mixtures of alkyl carbonates with non-active metal, graphite and lithium electrodes. FTIR spectroscopy, XPS, EQCM, in situ AFM imaging, and DSC were used in conjunction with standard electrochemical techniques. The study also included a comparison between LiBOB and LiPF6 solutions. The development of a favorable surface chemistry in LiBOB solutions that provides better passivation to Li and Li-graphite electrodes was clearly evident.