Multi-ion Modulated Single-Step Synthesis of a Nanocarbon Embedded with a Defect-Rich Nanoparticle Catalyst for a High Loading Sulfur Cathode
Jian Wang, Lujie Jia, Haitao Liu, Chong Wang, Jun Zhong, Qingbo Xiao, Jin Yang, Shaorong Duan, Kun Feng, Na Liu, Wenhui Duan, Hongzhen Lin, Yuegang Zhang
Abstract
Oxygen defect-rich iron oxide (ODFO) nanoparticle catalyst on nanocarbon is in situ synthesized with the assistance of multi-ion modulation in one pot. The nanoparticle catalyst is employed to propel electrochemical kinetics in lithium/sulfur batteries. Electrochemical analysis and theoretical simulation evidently verify the critical role of defect sites on catalyzing conversion reactions of sulfur species and reducing energy barriers. As a consequence, the ODFO-enhanced sulfur cathode exhibits a high specific capacity of 1489 mA h g–1 at 0.1 C, an excellent rate performance of 644 mA h g–1 at 10 C, and a superior cycling stability with an average capacity fading rate of as low as 0.055% per cycle under an ultrahigh rate of 10 C. More importantly, even with a high sulfur loading of 11.02 mg cm–2, the Li/S cell can still deliver an areal capacity of 8.7 mA h cm–2 at 0.5 C (9.23 mA cm–2). Such performance is the highest among reported metal oxide-catalyzed sulfur cathodes. This work opens a new route to boosting conversion reaction kinetics by introduction of active oxygen defect sites in electrodes of various emerging ultrafast batteries.