Yttrium-Containing Solid Electrolyte Interphase Safeguards Lithium Anodes in Lithium–Sulfur Batteries

Abstract

Lithium–sulfur batteries (LSBs) are regarded as significantly potential future-oriented power sources. Nevertheless, one of the significant challenges that needs to be addressed in LSBs is lithium dendrite overgrowth. In this study, we have introduced 1% LiNO3 and 2% Y(NO3)3 (1% Li & 2% Y) additives to form an in situ solid electrolyte interface (SEI) layer to overcome the challenges of lithium dendrite overgrowth and enhance the electrochemical performance in LSBs. Including Y(NO3)3 (2% Y) as an additive builds the emergence of the composite passivation layer containing Y2S3/Li2S/Li2S2 covering the Li anode. Y2S3 not only effectively enhances the mechanical stability of the SEI layer on the Li anode, but also catalyzes the decomposition of Li2S at the cathode. In addition, the incorporation of LiNO3 also contributes to an improved coulomb efficiency of the LSB. The electrolyte formulated with 1% Li & 2% Y additives demonstrates a capacity of 711.9 mA h g–1 after 250 cycles at 0.5C, showcasing excellent cycle stability. Furthermore, the capacity decay rate for each cycle is only 0.08%. These results validate the effectiveness of the 1% Li & 2% Y additives in protecting the lithium anode effectively, thereby establishing the potential for developing environmentally friendly and long-lasting batteries.