摘要 |
A siliceous filler-reinforced microporous polymeric material battery separator wherein the siliceous filler comprises agglomerates of substantially hollow spherical particles of amorphous, precipitated silica having a predominant hollow spherical particle size of between 5 x 10<-6> mm and 5 x 10<-3> mm (between 0.005 and 5.0 microns), the siliceous filler having a surface area of between about 50 and 200 square metres per gram, and an oil absorption of from about 150 to 300 millilitres per 100 grams of filler. |