Size effect of electrocatalyst enabled high-performance lithium-sulfur batteries

The shuttle effect of polysulfides and the slow redox reaction kinetics are two key challenges that constrain the practical application of lithium-sulfur (Li-S) batteries. Interlayer engineering is considered an effective strategy to address these issues. However, the geometrical design of functionalized interlayers has not been thoroughly analyzed, and few studies have focused on the parameters (e.g., size effect) that influence the electrochemical performance of interlayers. Given the above considerations, we constructed carbon-supported Sb metal particles (SNF1 and SNF2) with size effect as the interlayer of high-performance Li-S batteries by different integration methods, respectively. The experimental results and theoretical calculations demonstrate that variations in the size of nanoparticles result in interlayers with differing abilities to inhibit and convert polysulfides. The small nanoparticles in SNF1 provide abundant catalytic sites for targeting polysulfides. Consequently, the SNF1-based Li-S battery exhibits excellent cycling performance, maintaining stability for up to 500 cycles at a current density of 1.0C, with a capacity decay rate as low as 0.08 %. Notably, the Li-S battery retains a high reversible capacity of 482 mAh g- 1 after 67 cycles at 0.2C, even under a high sulfur load of 8.7 mg cm- 2. This study presents a novel approach to design functionalized interlayers for high-performance Li-S batteries.