Molten salt assisted fabrication of ferroelectric BaTiO3 based cathode for high-performance lithium sulfur batteries

Abstract

As a promising candidate for the next-generation power source with high energy density and low cost, the lithium-sulfur battery is attracting considerable research interests while the development of efficient cathode materials with low shuttle effects of polysulfides still remains a grand challenge. Herein, different from the conventional mechanical mixing methods, we present an effective molten-salt protocol for loading ferroelectrics into the hierarchical porous carbon matrix as the host for the sulfur cathode. As the proof of concept, prototype BaTiO3 is used as the ferroelectric additive. Interestingly, the rationally-fabricated composite structure ensures homogeneous distribution of ferroelectric particles within the carbon framework through the liquid medium and effectively avoids aggregation of ferroelectrics that was always seen in traditional compositing methods. Profiting from the electrochemically active merits including uniform dispersion of ferroelectrics, activated carbonaceous porous structure, enhanced crystallinity of BaTiO3, and high-strength component interactions that were introduced by the molten-salt strategy, the as-prepared cathode presented excellent rate capabilities and outstanding cycling stability. This work marks a step ahead towards the fabrication of high-performance ferroelectric based composites for advanced energy conversion and storage use.