Development of high-energy non-aqueous lithium-sulfur batteries via redox-active interlayer strategy
Byong‐June Lee, Chen Zhao, Jeong‐Hoon Yu, Tong‐Hyun Kang, Hyean‐Yeol Park, Joonhee Kang, Yongju Jung, Xiang Liu, Tianyi Li, Wenqian Xu, Xiaobing Zuo, Gui‐Liang Xu, Khalil Amine, Jong‐Sung Yu
Abstract
Abstract Lithium-sulfur batteries have theoretical specific energy higher than state-of-the-art lithium-ion batteries. However, from a practical perspective, these batteries exhibit poor cycle life and low energy content owing to the polysulfides shuttling during cycling. To tackle these issues, researchers proposed the use of redox-inactive protective layers between the sulfur-containing cathode and lithium metal anode. However, these interlayers provide additional weight to the cell, thus, decreasing the practical specific energy. Here, we report the development and testing of redox-active interlayers consisting of sulfur-impregnated polar ordered mesoporous silica. Differently from redox-inactive interlayers, these redox-active interlayers enable the electrochemical reactivation of the soluble polysulfides, protect the lithium metal electrode from detrimental reactions via silica-polysulfide polar-polar interactions and increase the cell capacity. Indeed, when tested in a non-aqueous Li-S coin cell configuration, the use of the interlayer enables an initial discharge capacity of about 8.5 mAh cm −2 (for a total sulfur mass loading of 10 mg cm −2 ) and a discharge capacity retention of about 64 % after 700 cycles at 335 mA g −1 and 25 °C.