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.