Cooperative catalytic interface accelerates redox kinetics of sulfur species for high-performance Li-S batteries

The high theoretical energy density and low cost make lithium-sulfur (Li-S) batteries an ideal choice for next -generation energy storage devices. However, the slow kinetics cause the reaction process to be incomplete and low reaction rate. To solve this problem, a novel cooperative catalytic interface with fine molecular regulation mechanism is designed by taking advantage of the electronic correlation between the catalyst and polysulfides (LiPSs), which multi-step process contains chemical adsorption, catalytic activity center and lithium-ion transfer. The cooperative catalytic interface greatly accelerates the kinetics of LiPSs conversion, precipitation of Li2S in discharging, and insoluble Li2S decomposition in charging process. Therefore, the PdNi@ND-C3N4-based cathode exhibits an outstanding electrochemical performance. Even under the condition of high sulfur loading of 6.0 mg cm(-2), the constructed Li-S batteries demonstrate the ultralow capacity decay rate of 0.025% per cycle up to 1000 cycles. Moreover, its catalytic mechanism is deeply analyzed through DFT theory and in(ex)-situ technologies. This work will open a new window for the rational design of Li-S electrocatalyst based on cooperative interface.

Automated summary

By designing a cooperative catalytic interface with fine molecular regulation mechanism, the reaction kinetics in Li-S batteries are greatly accelerated, leading to outstanding electrochemical performance and low capacity decay rate even at high sulfur loading levels. This work also provides insights into the catalytic mechanism through DFT theory and in(ex)-situ technologies.