The Effects of Electrolyte Additives on Li4Ti5O12 and How They Impact Gassing

Thursday, 1 June 2017: 10:36
Grand Salon C - Section 13 (Hilton New Orleans Riverside)
M. S. Milien, J. Hoffmann (University of Rhode Island), J. Li, M. Payne, S. Stephenson, J. Sans (BASF), and B. L. Lucht (University of Rhode Island)
Batteries consisting of Li4Ti5O12 (LTO) anodes do not require the formation of a solid electrolyte interface to deliver robust high-rate performance at room temperature, however performance suffers at elevated temperatures due to gassing. Research has linked this gassing to the instability of the electrolyte on the surface of charged LTO at elevated temperatures. If this is the case a passivation layer that prevents the electrolyte from coming into contact with the charged surface of LTO should hinder gassing. Several classes of electrolyte additives have been investigated in Li4Ti5O12/LiMn2O4 coin cells and pouch cells. ATR-FTIR and X-ray photoelectron spectroscopy has been used to gain an understanding of the surface films formed with different additives while in-situ gas measurements based on Archimedes’ principle and gas chromatography have given insight into how the implementation of these additives affects gassing. The results from this study enable the selective design of surface films for LTO anodes, which impedes gassing at elevated temperatures without sacrificing performance.