Study on the effect of carbon nanotubes loaded with cobalt disulfide modified multifunctional separator on Li-S battery

Abstract

To solve the “deadliest” shuttle effect in Li-S battery, the design of appropriate separator become more and more important for better electrochemical performance. CoS2/CNTs composites were obtained by loading cobalt disulfide on the surface of CNTs through two-step pyrolysis. Through morphological analysis and physical property characterization, CoS2 was proved to be well loaded on CNT, and there was a good contact between the composite and PP separator. Inorganic metal sulfides in the modified layer of CoS2/CNTs can enhance the utilization of active sulfur materials through the enhanced chemical adsorption of LiPSs, which is further enhanced by the high electrical conductivity of CNTs. Moreover, the composite material can also accelerate the catalytic conversion of LiPSs, accelerate the ion diffusion rate, weaken the reaction polarization, effectively weaken the capacity decline caused by the shuttle effect, and enhance the electrochemical performance of the system.