Sustainable and dual-optimized electrode design from waste resources for high-energy lithium–sulfur batteries

Lithium-sulfur batteries (LSBs) are considered a next-generation energy storage solution due to their exceptional theoretical capacity, cost-effectiveness, and environmental sustainability. However, their commercialization is hindered by severe lithium dendrite formation, polysulfide shuttle effects, and rapid capacity decay. To address these challenges, this study introduces a novel dual-modification strategy, focusing on stabilizing both the anode interface and cathode. A Zn-based artificial solid electrolyte interphase (ASEI) layer, derived from end-of-life Zn-C batteries, was engineered onto the lithium anode to regulate Li + diffusion, suppress dendrite growth, and mitigate polysulfide crossover. This waste-derived ASEI layer acts as a protective shield, enhancing electrochemical stability and extending cycle life. Complementing this, the cathode was modified using activated carbon derived from single-use respiratory masks (RMs), exhibiting an ultra-high surface area of 2407 m² g⁻¹. This tailored sulfur host effectively confines lithium polysulfides, suppressing the shuttle effect and improving sulfur utilization. To ensure scalability, microwave-assisted treatment and immersion coating were employed for cathode and anode modification, respectively. The dual-modified LSB demonstrated a remarkable specific capacity of 1180 mAh g⁻¹ at 0.1 C, retaining 78% of their initial capacity after 400 cycles at 0.5 C—far outperforming untreated cells, which retained only 42% under identical conditions. By transforming medical waste into high-performance electrode materials, this study presents a cost-effective and sustainable pathway to advance LSB technology, bridging the gap between material circularity and next-generation energy storage solutions. • Significantly enhanced electrochemical performance through the application of waste-derived materials. • Sustainable modification of both anode and cathode for higher-performance Li-S batteries. • Application of cost-effective and scalable methods in both anode and cathode modification. • High-capacity retention (78%) due to the synergistic effect of a hierarchical carbon host and coated Li anode.