ABSTRACT: Lithium sulfur (Li-S) batteries have attracted increasing attention because of their high theoretical capacity, natural abundance, low cost and environmental friendliness. Assuming Li2S as the end product, the maximum specific capacity and energy from Li-S batteries are 1675 Ah kg−1 and 2650 Wh kg−1, respectively, significantly higher than those of state-of-the-art lithium ion batteries.
However, the low electrical conductivity (5 × 10−30 S cm−1) of sulfur and the “shuttle reaction” caused by the soluble polysulfides are detrimental to Li-S battery performances, leading to low utilization rate of sulfur, poor Coulombic efficiency, fast capacity fading and self-discharge. Although there are many approaches reported in literature to address the challenges in Li-S system, the sulfur content in S/C composite, electrode thickness and testing conditions vary largely in different groups, making the direct comparison or evaluation of various methods a difficulty.
This talk will discuss the fundamental research in Li-S batteries from electrochemical point of view by using consistent sulfur cathode baseline cathode and testing conditions. The knowledge gained from these baseline cathodes were then successfully transferred into thick sulfur cathode with practical usable mass loadings. The entangled electrochemical and chemical reactions associated in Li-S batteries were further elaborated by using advanced characterization techniques in an attempt to provide new insights for this battery system.
Bio-sketch
Dr. Jie Xiao is currently a staff scientist at PNNL. She received her Ph.D degree in materials chemistry from State University of New York at Binghamton in 2008. Before that, she graduated from Wuhan University, China, with M.S.(2004) and B.S (2001) degrees in Electrochemistry. She has over 10 years’ research experience in electrochemical energy storage and conversion, with focused expertise on battery technologies such as Li-ion, Li-sulfur, metal-air batteries, and electrolyte development. At PNNL, she leads research thrusts focused on the fundamental study and practical applications of different battery technologies spanning from micro-batteries for wireless sensors to advanced batteries for vehicle electrification. Dr. Xiao is the recipient of a few awards including Ronald L. Brodzinski Early Career Exceptional Achievement Award, R&D 100 Award, Zappard award (American Chemical Society) and a few others. Dr. Xiao has published more than 60 peer-reviewed journal papers, 2 book chapters and filed 13 US patents (issued and applied) in the field of energy storage technologies.