Patent ID: 7129004
Filing Date: 2006-10-31
Classification: H01M,Y02E,Y02P

Abstract:
1. A separator for use in zinc/bromine secondary batteries comprising a polyethylene having an overall viscosity average molecular weight of not less than 350,000 and not more than 2,000,000 containing not less than 10 wt. % and not more than 30 wt.% of a polyethylene having a molecular weight of 1,000,000 or more and fine particulate silica, wherein the ratio by weight of polyethylene/fine particulate silica is more than 1 and less than 1.5, and the ratio of the number of silicon atoms (Si) to the number of carbon atoms (C), Si/C, exposed on the surfaces of said separator excluding cross-sectioned surfaces thereof is not less than 0.01 and less than 0.2 as determined by X-ray photoelectron spectroscopy (XPS).