N, N-Diethyltrimethylsilylamine (DETMSA) As Electrolyte Additive for Si Based High Energy Lithium-Ion Batteries

Silicon is a highly promising high capacity anode material for high energy lithium-ion batteries for electric vehicle application. Great progress has been made especially in the area of material level on the nano scale. 1 However, the electrolyte research tailored to further improve the performance of the Si anode is limited. 2 In this paper, we present a new electrolyte additive N, N-diethyltrimethylsilylamine (DETMSA) which showed great improvement over the conventional carbonate electrolyte using the fluoroethylene carbonate as additive. Our experiment data showed that with addition of 0.5 wt. % of DETMSA to the baseline electrolyte 1.2 M LiPF 6 EC/EMC+10% FEC, the Li/Si-graphite cell gained a 10% improvement in capacity retention increase with high coulombic efficiency at room temperature. The functioning mechanism of the new electrolyte additive for Si anode was investigated by the XPS, SEM/EDX and FT-IR. 3 References: He, M., Sa, Q., Liu, G., & Wang, Y. (2013). Caramel Popcorn Shaped Silicon Particle with Carbon Coating as a High Performance Anode Material for Li-Ion Batteries. ACS applied materials & interfaces , 5 (21), 11152-11158. Zhang, S. S. (2006). A review on electrolyte additives for lithium-ion batteries. Journal of Power Sources , 162 (2), 1379-1394. Zhang, S., Ding, M. S., Xu, K., Allen, J., & Jow, T. R. (2001). Understanding solid electrolyte interface film formation on graphite electrodes. Electrochemical and Solid-State Letters , 4 (12), A206-A208.