Gas switch

Claim 1

An air cell battery comprising: an anode casing containing anode material and a cathode casing containing cathode material, said cathode casing having an opening; an insulator located between and attached to said anode casing, and said cathode casing and a separator positioned between said anode material and said cathode material; a bidirectional gas switch comprising; a single membrane covering said opening in said cathode casing, said membrane having at least first and second sides and having at least one formed passageway having a predetermined geometry, said membrane and said cathode and anode casings thereby defining an inner region within said air cell battery and an outer region external to the air cell battery; a liquid having a low vapor pressure contained at least within said passageway of said membrane when a pressure difference across said membrane between said inner and outer regions is less than a first predetermined value, thereby preventing an exchange of gas between said inner region and said outer region, said liquid flowing substantially out of said passageway and onto a side of said membrane adjacent said gas containing region having a lower pressure value when the air cell battery supplies electrical current and oxygen is extracted from said inner region to cause said pressure difference across said membrane to exceed a second predetermined value thereby opening said passageway and allowing oxygen from said outer region to move into said inner region, and wherein, when the air cell battery ceases to supply electrical current, said pressure difference becomes less than said first predetermined value and said liquid flows back into said passageway thereby closing said passageway.