Lithium battery separator materials - predict durability?

[Lapwing]

I was wondering if anyone knows the separator materials used in the commonly used Lithium cells we have done torture testing and have discharge data for?

Headway, A123, ping, Konion, Thundersky, PSI, Lifebatt, K2, Phet, Valence etc.

It seems to me that the separator material is every bit as important as the battery anode and cathode formulation, with respect to safety and durability and internal impedance.

There are an awful lot of different types used.
Hear is a couple of links.

http://www.scitopics.com/Battery_Separator.html

Doc bass experiment with squashed Caterpillar got me thinking about membranes...........
http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=9158&p=141561&hilit=caterpillar#p141561

"The LG Chem cells use a proprietary lithium manganese spinel (LiMn2O4) material for the cathode with additives to improve calendar life under high temperature conditions; an amorphous carbon anode; a ceramic coating on the separator (the safety-reinforced separator, SRS) to minimize potential thermal runaway due to an internal short; and a LiPF6 electrolyte in organic solvents (gel type). "

http://www.greencarcongress.com/2009/01/gm-to-manufactu.html#more

I'll bet beer :? thatTeflon based membranes hold up longer, are more stable and are a lot more heat resistant than polyethylene - but what about all the others?

http://www.gore.com/MungoBlobs/1017/941/excellerator_separators.pdf

 

[Lapwing]

Looking at the MSDS for Thundersky batteries they use a PE - polyethylene separator. One can infer that localised high temps from c>3 would kill them, and that larger cells and larger battery packs need careful current and heat management.

What do Headway and Lifebatt use?