Three new bifunctional additives for safer nickel-cobalt-aluminum based lithium ion batteries

Abstract

Three different types of new electrolyte additives were adopted as flame retardant to improve the safety of nickel-cobalt-aluminum (LiNi0.8Co0.15Al0.05O2, abbreviation NCA) based lithium batteries. By adding 5 wt% of the additives, an obvious flame retardant effect can be observed for the electrolyte. Furthermore, it was found that the additives can help for forming a stable cathode electrolyte interface (CEI) film on the NCA cathode, which are important for enhancing the thermal stability of the electrolyte and make the electrolyte obviously reduce the flammability, as well as good effect on the cycling cycle performance of the battery. These results indicate that our flame retardant are favorable additives in conventional liquid electrolytes for rechargeable lithium-ion batteries with good safety and high performances.