Sustainable full-cell NCM||Graphite system with superior stability: The hybrid impact of sulfone-containing and flame-retardant additives on interface formation and cyclability

Abstract

S-containing additives improve the performance, lifetime, and sustainability of lithium-ion batteries (LIBs) through the stabilization of electrode-electrolyte interfaces, modification of electrolyte properties, and facilitating the efficient resource utilization and rapid Li+ migration. Non-etheless, fire safety, extended shelf life, and capacity maintenance are critical concerns for commercial LIBs. Herein, a S-containing film-forming additive, including 4,4-diaminodiphenylsolfon (DADP) by incorporating flame retardancy of dimethyl methyl phosphonate (DMMP) was considered toward taking the barriers of above-mentioned challenges. Based on the calculation, the additives decompose sequentially to produce a distinct SEI via a narrower energy gap under both cathodic and anodic conditions. The NCM532||Graphite with DADP/DMMP showed the enhanced preservation and stability of structure, defined by XRD, Rietveld refinement pattern, SEM, and FT-IR. While the DMMP decreased the fire risk and lowered the capacity due to side reactions, the DADP improved the capacity loss, where the retention rate was 94.91%, 92.01%, 81.29%, and 76.22% within 100, 200, 300, and 400 cycles, respectively. The additive also maintained a capacity of 1123.115 mAhg−1 for 650 cycles, demonstrating excellent cyclability. Therefore, DADP/DMMP facilitate the formation of stable SEI layer, reduce fire risk, improve cycle stability, and offer an achievable path to develop the safe and long-lasting commercial batteries.