Suppressing Lithium Polysulfide Shuttle in Li-S Batteries Using the AlPC Composite for Enhanced Stability and Performance.

This study presents the aluminum phosphate composite (AlPC) composite as a novel cathode material for lithium-sulfur (Li-S) batteries, addressing the polysulfide shuttle effect, a key challenge in Li-S battery performance. Synthesized via hydrolytic condensation and low-temperature calcination, the composite integrates aluminum alkoxide with phosphate to form a 3D structure that immobilizes lithium polysulfides (LiPS), enhancing battery efficiency and lifespan. Experimental analyses, including visible LiPS adsorption tests, and electrochemical measurements, demonstrate the superior performance of AlPC over traditional cathodes. Electrochemical tests show that AlPC/S batteries exhibit exceptional discharge capacities and stability, outperforming titanium-based cathode and Super P cathode. At 0.5 C, the battery has an initial capacity of 837 mAh/g with a decay rate of 0.06% per cycle, and at 3 C, an initial capacity of 529 mAh/g with a decay rate of 0.08% per cycle. Increased sulfur loading does not affect LiPS control, with a 2.1 mg sulfur-loaded battery showing a decay rate of 0.03% over 750 cycles. Density functional theory (DFT) calculations confirm strong LiPS interactions, essential for efficient LiPS capture. This research promotes sustainability through a scalable, eco-friendly production process, minimizing environmental impact and advancing high-energy-density battery technologies.