Carbon nitride based mesoporous materials as cathode matrix for high performance lithium–sulfur batteries

Abstract

A facile silica template nanocasting method was adopted to effectively synthesize mesoporous carbon nitride (MCN) based materials as cathode matrixes for advanced lithium/sulfur (Li/S) batteries. The materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The MCN/S composite cathode displays excellent electrochemical performance with initial discharge capacities of 1284.5 and 1107.1 mA h g⁻¹ for 66.7 wt% active material at 0.1 and 0.5C, respectively. And it presents good rate performance and stability with remaining discharge capacity of 828.4 mA h g⁻¹ after 100 cycles at 0.5C. The excellent performances are mainly attributed to the crosslink mesoporous structure and the strong chemical interaction between sulfur and carbon–nitrogen framework, which not only can provide polysulfides reservoirs and transport channels for the transportation of ions and electrons within MCN/S, but also is beneficial to restrain polysulfides migration.