Ketjen Black/Mg0.6Ni0.40O composite coated separator for lithium-sulfur batteries with enhanced electrochemical performance

摘要

Lithium-sulfur (Li-S) batteries have attracted much research interest due to its high energy density. However, the practical application of Li-S batteries was limited by low discharge capacity and short cycle life. In this work, Ketjen Black/Mg0.6Ni0.4O composite is firstly used to modify separator in Li-S batteries, which exhibit improved discharge capacity and long cycle life. The cell with KB/Mg0.6Ni0.4O composite coated separator keeps a discharge capacity of 530 mA h g(-1) after 350 cycles at 0.5 C. Electrochemical analysis indicates that KB/Mg0.6Ni0.4O composite layer can not only inhibit the diffusion of polysulfides and reduce battery internal resistance, but also catalyze the redox reaction in charge/discharge process.