Establishing Transition Metal Phosphides as Effective Sulfur Hosts in Lithium-Sulfur Batteries through the Triple Effect of "Confinement-Adsorption-Catalysis"

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2023-10, Vol.19 (42), p.e2303599-e2303599
• Main Authors: Wang, Fangzheng, Han, Yuying, Xu, Rui, Li, Ang, Feng, Xin, Lv, Shengyao, Wang, Tao, Song, LeLe, Li, Jing, Wei, Zidong
• Format: Article
• Language: English
• Subjects: Adsorption; Catalysis; Cathodes; Commercialization; Confinement; Decay rate; Density functional theory; Discharge; Electronic structure; Lithium sulfur batteries; Nanoparticles; Nanotechnology; Phosphides; Sulfur; Transition metals
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202303599

Structurally optimized transition metal phosphides are identified as a promising avenue for the commercialization of lithium-sulfur (Li-S) batteries. In this study, a CoP nanoparticle-doped hollow ordered mesoporous carbon sphere (CoP-OMCS) is developed as a S host with a "Confinement-Adsorption-Catalysis" triple effect for Li-S batteries. The Li-S batteries with CoP-OMCS/S cathode demonstrate excellent performance, delivering a discharge capacity of 1148 mAh g at 0.5 C and good cycling stability with a low long-cycle capacity decay rate of 0.059% per cycle. Even at a high current density of 2 C after 200 cycles, a high specific discharge capacity of 524 mAh g is maintained. Moreover, a reversible areal capacity of 6.56 mAh cm is achieved after 100 cycles at 0.2 C, despite a high S loading of 6.8 mg cm . Density functional theory (DFT) calculations show that CoP exhibits enhanced adsorption capacity for sulfur-containing substances. Additionally, the optimized electronic structure of CoP significantly reduces the energy barrier during the conversion of Li S (L) to Li S (S). In summary, this work provides a promising approach to optimize transition metal phosphide materials structurally and design cathodes for Li-S batteries.