Liang, L.; Gao, L.; Ma, Z.; Cao, Q.; Jing, B.; Wang, X.; Lu, Y.; Wang, W.: Phosphorus-doped few-layer graphite wrapped metallic cobalt as interlayer for advanced lithium-sulfur batteries. Materials Today Energy 37 (2023), p. 101415/1-7
10.1016/j.mtener.2023.101415
Abstract:
The shuttle effect and sluggish redox kinetics of sulfur cathode are the main barriers to commercializing lithium-sulfur (LieS) batteries. Fabricating functional interlayers is considered as one of the efficient approaches to suppress the shuttle effect while accelerating the conversion kinetics of polysulfides. Herein, the nanofiber-type interlayer composed of cobalt wrapped with few-layer phosphorus-doped graphite (CoPG) is elaborately designed, which is expected to chemically adsorb the polysulfides while accelerating the redox conversion of polysulfides anchored on phosphorus-doped graphite. Electro- chemical measurements sufficiently verify that the usage of the designed CoPG interlayer significantly prolongs the longevity of LieS batteries, reaching 694 mAh/g with a capacity decay rate of 0.11% at the current density of 2.0C. Remarkably, LieS battery sustains for 125 cycles and maintains ultrahigh capacity retention of 92% at the current density of 0.2C even with a sulfur loading of 5.8 mg/cm 2 . The theoretical computation further confirms the intensive interactions between CoPG and polysulfides, consistent with the experimental outcomes. Encapsulating the electrocatalyst with a few-layer polarized graphite en- ables the interlayer with adsorption and catalysis functions, which provides a promising strategy for advanced LieS batteries.