A bifunctional electrolyte additive ammonium hexafluorophosphate for long cycle life lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are regarded as the next-generation battery systems for their high theoretical specific capacity andenvironmental friendliness. However, some hard knots such as the “shuttle effect” and lithium dendrite growth impede the engineering application. Here, a bifunctional electrolyte additive (ammonium hexafluorophosphate (AFP)) was chosen to improve the electrochemical performance of Li-S batteries. The addition of AFP has been proved to facilitate the dissolution of Li2S, which reduces the decay of battery capacity and improves the electrochemical kinetics. Meanwhile, AFP induces the formation of “F-rich” SEI, which protects the anode. This work provides a bifunctional AFP electrolyte additive to enhance the performance of Li-S batteries.