High coulombic efficiency and high-rate capability lithium sulfur batteries with low-solubility lithium polysulfides by using alkylene radicals to covalently connect sulfur

A new strategy is reported to stabilize sulfur cathodes with alkylene radicals through the formation of weakly soluble lithium polysulfides, which enables nearly 100% Columbic efficiency at current rates from 0.2C to 6 C as well as outstanding rate capability with a high capacity of 702 mAh g−1 at 6 C.301