Constructing honeycomb-structured LaCoO3 as an efficient polysulfide converter on the separator to achieve practical lithium-sulfur batteries

Owing to its remarkable energy density and specific capacity, lithium-sulfur (Li-S) battery has emerged as one of the most promising energy storage devices. Nevertheless, the shuttle effect and the sluggish conversion of polysulfides significantly impede the practical application of Li-S batteries. Hence, a LaCoO 3 functional material with a unique honeycomb structure was designed as an efficient polysulfide converter. The honeycomb-structured LaCoO 3 not only exhibits strong bonding energy towards polysulfides but also possesses abundant adsorption sites on its surface. The LaCoO 3 material also shows excellent catalytic properties to quickly convert the adsorbed and aggregated polysulfides, effectively suppressing the shuttle effect. Moreover, the honeycomb structure of LaCoO 3 can facilitate the rapid wetting and infiltration of the electrolyte. Consequently, the Li-S cell with LaCoO 3 functionalized separator provides an areal specific capacity of 3.10 mAh cm −2 after 150 cycles under high sulfur loading of 6.52 mg cm −2 . Moreover, under practical conditions where the electrolyte content is as low as 7 μL mg −1 and the sulfur loading is 7.96 mg cm −2 , the Li-S battery equipped with LaCoO 3 -separator can still provide an areal specific capacity of 5.93 mAh cm −2 after 50 cycles.