An AlOOH-coated polyimide electrospun fibrous membrane as a high-safety lithium-ion battery separator

To improve the safety of lithium-ion batteries (LIBs), an AlOOH-coated polyimide (API) fibrous membrane as an inorganic composite separator is developed via an electrospinning technique and a subsequent blade-coating process. Benefiting from the good thermostability of polyimide and the flame-retarding property of AlOOH, the API separator shows excellent thermal stability and flame retardance. Compared with commercial polyolefin separator, the API separator exhibits superior electrolyte wettability and electrochemical stability. The Li||LiCoO 2 cell using the API separator exhibits the enhanced cycling performance and rate capability. Thus, the as-prepared API separator is promising as a new kind of inorganic composite separator for advanced LIBs with high safety.