Internal field-driven redox control and shuttle suppression via ferroelectric Ba0.9Sr0.1TiO3 in lithium–sulfur batteries

The performance of lithium–sulfur batteries (LSBs) is critically hindered by polysulfide (PS) migration and sluggish redox kinetics. In this study, we present a field-assisted electrochemical enhancement strategy through the incorporation of ferroelectric Ba0.9Sr0.1TiO3 (BST) nanoparticles into sulfur/carbon black (S/CB) composite cathodes. The spontaneous polarization of BST generates internal electric fields that effectively confine migrating PSs, promote Li-ion transport, and stabilize redox kinetics within the cathode framework. Structural characterization (x-ray diffraction, Raman), morphological (scanning electron microscopy/energy dispersive x-ray spectroscopy), and electrochemical characterizations (cyclic voltammetry, electrochemical impedance spectroscopy, galvanostatic charge–discharge) confirm the retention of structural integrity, improved graphitic ordering, and enhanced redox kinetics. The optimized composite cathode exhibited improved specific capacity (∼820 mA h g−1), with ∼60% retention after 100 cycles at 100 mA g−1, demonstrating suppressed shuttle effect and robust cycling. The findings highlight the efficacy of the ferroelectric BST framework in regulating interfacial reactions, presenting a viable pathway for robust, high-performance LSBs for future energy applications.