A multifunctional nano filler for solid polymer electrolyte toward stable cycling for lithium-metal anodes in lithium–sulfur batteries

Abstract

Lithium–sulfur (Li–S) batteries are considered as very promising energy storage systems due to their higher theoretical performance and lower active material cost. However, the notorious shuttle effect and lithium dendrite growth have severely restricted the industrial production of Li–S batteries. In this study, we used polyethylene oxide (PEO) as the matrix and added multifunctional nanofillers (nano In2O3) to effectively inhibit the shuttle effect caused by the dissolution of lithium polysulphides (LiPSs) in Li–S batteries. As a multifunctional filler, nano-In2O3 not only improves the ionic conductivity of the PEO electrolyte, but also forms a Li–In alloy layer in situ at the polymer/anode interface, which can cause the rapid diffusion of lithium ions and prevent the side reactions between lithium metal anode and the electrolyte. Achieving the effect of stabilizing the lithium metal anode and suppressing the shuttle effect. Multiple problems in the system are solved by introducing a single component with multiple functions. The symmetrical lithium battery based on the PEO/LiTFSI/In2O3 solid polymer electrolyte (PEO/LiTFSI/In2O3 SPE) has higher cycle stability (over 1200 h) because it is more stable to the lithium metal anode. The Li–S full battery also exhibits excellent electrochemical performance. After 500 cycles at 1C, its capacity can be maintained at 570 mAh g−1, the capacity decay rate is 0.038%. The coulombic efficiency (CE) during the cycle is also close 100%.