Repelling Polysulfide Shuttling in All-Solid-State Lithium-Sulfur Batteries Using Dynamic Anionic Polymers

Lithium-sulfur (Li-S) batteries are positioned as a promising alternative to current lithium-ion batteries as next-generation energy storage technologies. However, polysulfide shuttling poses a pressing barrier to realizing this target. Li-S batteries are characterized by their unique capabilities including high energy density and cost-effectiveness, however, the migration of polysulfide species within the battery electrolyte severely compromises their performance, leading to rapid capacity decay and reduced cycle life. Addressing this issue is crucial for unlocking the potential of Li-S batteries in applications ranging from portable electronics to electric vehicles.<br/>In response to this challenge, our research introduces an approach designed to inhibit the shuttling of polysulfide species in an all-solid-state Li-S battery using dynamic, anionic polymer networks. By developing a polymer electrolyte network that integrates charge centers with solvation-tuning side chains, we strategically modify the solvation environment to make it unfavorable for lithium polysulfides to diffuse into the bulk electrolyte, but instead to stay in place to participate the redox processes in the sulfur cathode. This dual-action mechanism effectively prevents polysulfide migration, thereby enhancing the battery's cycling stability and performance. We performed a comprehensive analysis combining experimental observations with density functional theory (DFT)-based calculations to elucidate the underlying interactions at play. We further used in situ optical monitoring, Raman spectroscopy, and X-ray absorption spectroscopy to obtain direct evidence of the polymer electrolyte's ability to repel lithium polysulfides during battery operation. The integration of these techniques provides a robust framework for understanding the complex dynamics influencing Li-S battery performance, offering insights that extend beyond conventional analytical methods.<br/>The implications of our findings offer a viable pathway to significantly improve the performance and extend the lifetime of Li-S batteries. By demonstrating a tangible solution to the polysulfide shuttling problem, our work contributes to the broader adoption of Li-S technology in a wide array of energy storage applications. As we continue to refine and optimize our polymer electrolyte design, we anticipate further breakthroughs that will solidify the position of Li-S batteries as a cornerstone of sustainable energy systems.