CeVO4/KB Nanoparticles on Shuttle Effect Inhibition in Lithium-Sulfur Battery Separator Modification

Graphical The shuttle effect in lithium-sulfur batteries has been a thorny issue, for which researchers have conducted a lot of studies. Of the various directions attempted, separator modification is more convenient and easy to operate. In this paper, CeVO 4 /KB material is proposed to improve the separator and suppress the shuttle effect through its catalysis and adsorption. Catalytic adsorption of the rare earth metal Ce and transition metal V, efficient binding of oxides to polysulfides, and physical adsorption of porous KB prevent the transport of polysulfides to the anode and facilitate the reaction kinetics. Of course, the CeVO 4 /KB/PP batteries show brilliant performances. The CeVO 4 /KB/PP cell achieves 1059.9 mAh g −1 and 92.3 % capacity recovery rate when 3 C is reverted to 0.2 C, demonstrating the outstanding reversibility provided by the CeVO 4 /KB/PP separator. In the long cycle test, the initial specific capacity reaches 1200.9 mAh g −1 with a capacity retention rate of 86.5 % after 100 cycles at 0.2 C. Even at 3 C, CeVO 4 /KB/PP batteries reach 882.7 mAh g −1 in the first cycle with a capacity decay rate of 0.063 % per cycle on 1000 stable cycles. This work provides guidance on the selection of future separator modification materials and expects other work to be a breakthrough. Lithium-sulfur (Li−S) batteries display promise as redox-based batteries, where separators are an essential part of preventing short-circuiting of the positive and negative electrodes, while the shuttle effect is a critical issue of separators. Currently, commercial PP separators are weak in inhibiting the polysulfides shuttling, so modified separators are needed to inhibit it to improve the battery performance. This paper reports that CeVO 4 /KB composites act as separator materials. CeVO 4 /KB modified PP separators enhanced the adsorption of LiPSs, accelerated the rate of Li + migration, and catalyzed the conversion of LiPSs. These bring about the effect that CeVO 4 /KB/PP batteries reach 1200.9 mAh g −1 in the first cycle with a capacity retention rate of 86.5 % after 100 cycles at 0.2 C and reach 882.7 mAh g −1 of the initial cycle with a capacity decay rate of 0.063 % after 1000 cycles at 3 C. This work introduces rare earth metal vanadates to modify the separator, adding new ideas for designing separators for good-performance batteries.