Patent ID: 7663865

Claim:
An electrolytic capacitor ( 40 ; 50 ) comprising an airtight housing ( 41 ; 51 ), electrodes ( 52 ; 52 ′; ...) immersed in an electrolytic solution, electrical contacts ( 54 ; 54 ′) connected to the electrodes and a multilayer polymeric sheet ( 10 ; 20 ; 32 ; 43 ; 53 ) for sorption of harmful substances, the multilayer polymeric sheet comprising an inner layer ( 12 ; 22 ; 33 ) of polymeric material containing particles ( 11 ) of at least one getter material for sorption of harmful substances and at least one external protective layer ( 13 ; 23 , 23 ′; 34 ) of polymeric material impermeable to the electrolytic solution, wherein all of the polymeric materials are permeable to the harmful substances, and wherein: when the harmful substances comprise hydrogen, the getter material is at least one selected from non-evaporable getter alloys, unsaturated organic compounds, zeolites with a silver deposit, carbon nanotubes, palladium oxide, and cobalt(II,III) oxide; when the harmful substances comprise H 2 O, the getter material comprises at least one compound selected from alkaline-earth metal oxides, boron oxide and zeolites; and when the harmful substances comprise CO, the getter material comprises at least one compound selected from the following: cobalt(II,III) oxide, copper(II) oxide and potassium permanganate.