Engineering Triple-Phase Interfaces Enabled by Layered Double Perovskite Oxide for Boosting Polysulfide Redox Conversion

The electrocatalytic conversion of polysulfides is crucialto lithium-sulfurbatteries and mainly occurs at triple-phase interfaces (TPIs). However,the poor electrical conductivity of conventional transition metaloxides results in limited TPIs and inferior electrocatalytic performance.Herein, a TPI engineering approach comprising superior electricallyconductive layered double perovskite PrBaCo2O5+delta (PBCO) is proposed as an electrocatalyst to boost the conversionof polysulfides. PBCO has superior electrical conductivity and enrichedoxygen vacancies, effectively expanding the TPI to its entire surface.DFT calculation and in situ Raman spectroscopy manifestthe electrocatalytic effect of PBCO, proving the critical role ofenhanced electrical conductivity of this electrocatalyst. PBCO-basedLi-S batteries exhibit an impressive reversible capacity of612 mAh g(-1) after 500 cycles at 1.0 C with a capacityfading rate of 0.067% per cycle. This work reveals the mechanism ofthe enriched TPI approach and provides novel insight into designingnew catalysts for high-performance Li-S batteries.

Automated summary

A triple-phase interface engineering approach using the electrically conductive layered double perovskite PrBaCo2O5+delta (PBCO) is proposed to enhance the electrocatalytic conversion of polysulfides in lithium-sulfur batteries. DFT calculations and in situ Raman spectroscopy confirm that PBCO's enhanced electrical conductivity plays a critical role in the electrocatalytic effect. PBCO-based Li-S batteries exhibit an impressive reversible capacity of 612 mAh g(-1) after 500 cycles with a capacity fading rate of 0.067% per cycle. This work reveals the mechanism of the enriched triple-phase interface approach and provides new insights for designing high-performance catalysts for Li-S batteries.