Multifunctional SnO2 QDs/MXene Heterostructures as Laminar Interlayers for Improved Polysulfide Conversion and Lithium Plating Behavior

Abstract

Highlights The interfacing between SnO2 and MXene alters electronic structures, shifting the d-band center in transition metals, enhancing catalytic efficiency by reducing electron filling in antibonding orbitals. A binder-free, ultrathin, laminar heterostructured interlayer on polypropylene separator is demonstrated. The ionic sieving mechanism and efficient adsorption–catalysis process enable deeper charge/discharge cycle and improved stability. The improved catalytic conversion and suppressed lithium dendrites formation enable a high loading of 7.5 mg cm−2 and an initial area capacity of 7.6 mAh cm−2.

Keywords

• Lithium–sulfur battery
• Heterogeneous catalysis
• Heterostructure
• Redox kinetics
• Lithium dendrites