Phosphorus-containing additives contribute to the wide application of LSBs

Lithium-sulfur battery(LSBs) is a kind of high-performance energy storage battery, which is widely used in portable electronic equipment, electric vehicles and other industries. In recent years, the development of LSBs has attracted wide attention at home and abroad. However, electrolyte safety issues limit the development of lithium-sulfur batteries. 

To solve this problem, people add lithium-sulfur battery flame retardant additives to the organic electrolyte to improve the electrochemical performance and safety performance of LSBs . The ideal electrolyte additive should have the characteristics of good solubility, no side reactions, no toxicity or low toxicity. At present, the widely used electrolyte flame retardant additives mainly include organic phosphates, organic halides, composite flame retardants and some other flame retardants.

Phosphorus-containing additives with excellent performance are hot spots in the research of electrolyte additives for lithium-sulfur batteries. They not only have a high flame retardant effect, but also can improve the electrochemical performance of the battery and have a wide range of applications.

W. M.Zhao. et al. ^[1] reported that adding lithium difluorophosphate as a functional additive to carbonate-based electrolytes can slow down the combustion chain reaction process, which not only can improve the safety and stability of LSBs , but also can improve Electrochemical performance and specific capacity.

In addition to being used as a flame retardant, organic phosphide additives can also be used as SEI film-forming additives and conductive additives. Wang. et al. ^[2] showed that graphene, organic conductor PEDOT, and nitrogen and phosphorus co-doped bio-carbon to fix sulfur, developed a layered structure composite material with triple protection strategy, this unique layered structure can effectively fix sulfur, while improving conductivity and ensuring effective lithium ion transmission, thereby improving the performance of  LSBs

At present, organic liquid electrolyte is the most widely used electrolyte system for  LSBs. The development of new electrolyte additives with different functions, including phosphorus containing additives, is conducive to improving the performance of the electrolyte, so as to improve the stability and safety of  LSBs , which is still the research focus in the future.

Related links: PEDOT

references:

1. Zhao WM, Zheng GR, Lin M, et al. Toward a stable solid?electrolyte?interfaces on nickel?rich cathodes: LiPO2 F2 salt-type additive and its working mechanism for LiNi 0.5Mn 0.25Co 0.25O2 cathodes ［J］ .Journal of Power Sources, 2018, 380: 149?157.