High-Performance Cross-Linked Particle-Like LaNiO3 As a Multifunctional Separator to Significantly Enhance the Redox Kinetics of Lithium-Sulfur Batteries

The "shuttle effect" and slow conversion kinetics of lithium polysulfide severely hinder the practical application of lithium-sulfur (Li-S) batteries. A perovskite functional separator (LaNiO3@PP) was introduced into lithium-sulfur batteries for applications; the lanthanum and nickel elements on the A-site and B-site have been proved to have good adsorption and catalytic effects on LiPSs in previous studies, and constructing the material with such dual active sites can greatly enhance its adsorption capacity for LiPSs. LaNiO3 prepared by the sol-gel method has the characteristics of low raw material cost and a simple synthesis method, which is an important prerequisite for product commercialization. It is found that the impedance of LaNiO3@PP batteries is low, which is favorable for the kinetic process of the batteries. According to the self-discharge experiment, it can be proved that LaNiO3@PP has a good ability to suppress self-discharge, and the capacity loss is only 8.76% after 7 days of resting, because LaNiO3 converts polysulfide to sulfate and the sulfate intermediate to Li2S through further electrochemical reaction during the discharge process, which effectively suppresses the shuttle effect and reduces the loss of active material for LaNiO3@PP with significantly high specific capacity and rate capability as well as stable long-cycle performance. For an area loading of 1.106 mg cm(-2), the initial specific capacity at 0.1C is 1320.28 mAh g(-1), and the discharge specific capacity of 591.40 mAh g(-1) can still be maintained after 300 long cycles at 0.5C. When the area loading reached 4.926 mg cm(-2 )and the electrolyte-to-activator ratio (E/S) was 8.1 mu L mg(-1), and the initial capacity at 0.2C was 665.49 mAh g(-1), the good electrochemical performance was maintained after 50 cycles. This work provides a new strategy for the preparation of high performance and high stability Li-S battery separators