Safety and performance characteristics are mainly correlated with electrode materials, electrolytes and separators.  The presentation will outline many key functions that the separator serves in lithium-ion batteries and describes a separator design – specifically, AlOOH-based nanocomposite membranes – which addresses several critical safety concerns for high performance lithium-ion batteries.

      Boehmite(γ-AlOOH) separator, polypropylene(PP) separator and boehmite-PP separator 18650 Li-ion cells have been made, The safety performance of the different separator 18650 Li-ion cells have been investigated, especially by nail penetration which is well known to be the most difficult safety test for high energy density including NMC/NMA positive material 18650 cells and passing this test is critical for  xEV applications in China.

     The preliminary results show that the cycling performance of boehmite separator cells was better than the other two kinds of separator cells.   Cells using boehmite separator showed improved nail penetration performance compared with PP separator cells, which may be attributed to the excellent thermal stability of the boehmite separator.  More safety test results and cycling performance data of all three different separator cells will be further discussed in this presentation.