Enhanced polysulfide trapping in Li-S batteries by dipole alignment in ferroelectric BaTiO₃₃

Lithium-sulfur (Li-S) batteries are considered a promising option for next-generation energy storage systems due to their superior theoretical capacity (1675 mAh g^-1). However, their practical energy density and cycle life have not met expectations due to the shuttle effect, wherein polysulfides, as intermediate products, dissolve and migrate towards the lithium anode. This shuttle effect results in the loss of sulfur active materials and subsequent degradation of battery performance. To mitigate this issue, we have integrated a ferroelectric BaTiO₃ additive with dipole alignment into the cathode, exploiting its ferroelectric properties to adsorb polysulfides on the sulfur cathode, thereby mitigating the shuttle effect and enhancing battery performance. We have explored the relationship between the degree of dipole alignment in the ferroelectric BaTiO₃ and its effectiveness in polysulfide adsorption. Our research indicates that high dipole alignment correlates with increased surface potential, leading to effective polysulfide adsorption, thus significantly suppressing the shuttle effect and improving long-term battery performance.锂硫（Li-S）电池凭借其优异的理论比容量（1675 mAh g⁻¹），被视为下一代储能系统的极具前景的候选方案。然而，由于穿梭效应的存在，其实际能量密度与循环寿命尚未达到预期：作为中间产物的多硫化物会发生溶解并向锂负极迁移。该穿梭效应会造成硫活性物质的流失，进而导致电池性能劣化。为缓解这一问题，本研究将经过偶极取向处理的铁电钛酸钡（BaTiO₃）添加剂引入正极之中，利用其铁电特性实现硫正极表面对多硫化物的吸附，从而抑制穿梭效应并改善电池性能。本研究还探究了铁电钛酸钡的偶极取向程度与其多硫化物吸附效能之间的关联。研究结果表明，较高的偶极取向程度对应更高的表面电势，可实现高效的多硫化物吸附，从而显著抑制穿梭效应，提升电池的长期循环性能。