Lithium ion conductive Li1.5Al0.5Ge1.5(PO4)3 based inorganic–organic composite separator with enhanced thermal stability and excellent electrochemical performances in 5 V lithium ion batteries

Since 5 V lithium ion batteries have attracted more and more attentions and are deemed to be an important tendency in the future, the matched design of the separators has also become a necessary and significant work. In this work, the lithium ionic conducting glass ceramic Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 -polypropylene (PP) based inorganic–organic composite separator (LAGP-PP) is prepared. Compared with the pristine PP separator, the LAGP-PP separator owns enhanced thermal stability and wettability . Meanwhile, the LAGP-PP separator shows higher ion conductivity than the traditional Al 2 O 3 coated PP separator due to the more facile lithium ion diffusion channels in the coating layer . The superior C-rate capacity and cyclability in the LiNi 0.5 Mn 1.5 O 4 based 5 V lithium ion batteries indicate that the LAGP-PP separator is a good alternative for the traditional inert inorganic ceramic coated polyolefin separators and is a kind of promising candidate separator for the high voltage lithium ion batteries.