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

Since 20 years, titanium oxide materials and in particular, lithium titanate spinel Li 4 Ti 5 O 12 (LTO) were considered as promising negative electrode materials for lithium-ion cells. In the case of the TiNb 2 O 7 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 H 2 gas. The use of carbon coating as a mitigation strategy and its limitation is also discussed. Graphical abstract