A Mott–Schottky Heterogeneous Layer for Li–S Batteries: Enabling Both High Stability and Commercial‐Sulfur Utilization. Issue 14 (17th February 2022) - Shi, Mengjiao
Abstract: Lithium–sulfur batteries (LSBs) are severely impeded by their poor cycling stability and low sulfur utilization due to the inevitable polysulfide shuttle effect and sluggish reaction kinetics. This work reports a Mott–Schottky RGO‐PANI/MoS2 (RPM) heterogeneous layer modified separator for commercial‐sulfur‐based LSBs through the vertical growth of molybdenum sulfide (MoS2 ) arrays on the polyaniline (PANI) in situ reduced graphene oxide (RGO). Due to the synergistic effects of the "reservoir" constructed by MoS2 and RGO‐PANI, strong absorbability, high conductivity, and electrocatalytic activity, RPM exhibits a successive "trapping–interception–conversion" behavior toward lithium polysulfides. As a result, the LSBs assembled using a commercial‐sulfur as the cathode and RPM as modified layer exhibit high sulfur utilization (3.8 times higher than that of the unmodified separator at 5 C), excellent rate performance (553 mAh g −1 at 10 C), and outstanding high‐rate cycle stability (524 mAh g −1 after 700 cycles at 5 C). Moreover, even at a high sulfur loading of 5.4 mg cm −2, a favorable areal capacity of 3.8 mAh cm −2 is still maintained after 80 cycles. Theoretical calculations elucidate that such a systematic strategy can effectively suppress the shuttling effect and boost the catalytic conversion of intercepted polysulfides. This work may provide a feasible strategy to promote the practical application of commercial‐sulfur‐based LSBs. Abstract : A Mott–Schottky RGO‐PANI/MoS2 (RPM) heterogeneous layer with a "reservoir" structure is designed and used as a separator modification material for lithium–sulfur batteries. RPM exhibits a successive "trapping–interception–conversion" property toward lithium polysulfides and delivers both excellent rate performance and cyclability (553 mAh g −1 at 10 C/524 mAh g −1 after 700 cycles at 5 C).