A quantitative and qualitative study of gas generation observed in LiFePO4–TiNb2O7 cells

Abstract

Since 20 years, titanium oxide materials and in particular, lithium titanate spinel Li4Ti5O12 (LTO) were considered as promising negative electrode materials for lithium-ion cells. In the case of the TiNb2O7 compound (TNO), which has a larger theoretical lithiation capacity of 388 mAh g−1, few studies have focused on the outgassing of the material. In this work, we quantified the volume produced as a function of different cycling parameters and then characterized the produced species and show a prevalence of H2 gas. The use of carbon coating as a mitigation strategy and its limitation is also discussed.Graphical abstract