Review on Multi-Functional Separator for Li-S Batteries

Because lithium-ion batteries are not able to meet increasing demand for capacity density and power density, lithium metal batteries are given great expectations as the next generation of rechargeable batteries. As one of lithium metal batteries, lithium-sulfur (Li-S) batteries have attracted extensive attention because of their ultrahigh capacity density (1675 mAh g⁻¹) and low cost of sulfur. In order to overcome problems of active material attenuation, dendritic growth and volume expansion caused by the shuttle effect in Li-S batteries, researchers have adopted several methods such as adding electrolyte additives, electrode modification and separator modification. Among them, separator modification shows significant advantages in inhibiting the shuttle effect of lithium polysulfides. This paper reviews research progress of inhibiting the shuttle effect of Li-S batteries by separator modification in recent years, including direct design of new type separator and physical/chemical modification of separator surface. Through extensive reading and summarizing research results of separator modification of Li-S batteries, we give the possible development direction of Li-S batteries at the end of the paper.