The Polymer Society of Korea

여상구 (성균관대학교)

김수찬 (성균관대학교)

The increasing demand for energy storage in data-centric computing and electric mobility requires battery technologies that overcome trade-offs between energy density, cost, and durability. While LiFePO₄ (LFP) offers excellent safety and stability, its capacity is inherently limited, whereas sulfur-based conversion chemistry provides high capacity but suffers from polysulfide shuttling. Here, we develop an intercalation–conversion hybrid cathode integrating LFP and sulfur-based components. LFP functions as stable lithium host and polysulfide anchor, while the conversion component supplies high-capacity charge storage. Through optimization of cathode architecture and electrolyte chemistry, the hybrid cathode delivers over 3,000 cycles with an ultra-low capacity decay of 0.016% per cycle at 5 C and retains 91.6% capacity under practical cycling conditions as well as 76% in pouch cell operation, demonstrating a scalable strategy for durable, high-energy lithium-ion batteries.