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 LiPF6 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.