TECHNOLOGY FOCUS - POLYMERS - Preferred Polyoxyalkylene Ether: The polyoxyalkylene ether group, which is most preferably born by the first POS is a polyoxyethylene ether and/or polyoxypropylene.Preferred Polyorganosiloxane: The first POS is of Formula (I)R' = 2-50C radical;R, R'' = H, 1-8C alkyl (preferably methyl, ethyl, propyl, octyl, 3,3,3-trifluoropropyl) optionally substituted with at least one halogen preferably F, 5-8C optionally substituted cycloalkyl, 6-12C optionally substituted aryl, a 5-14C alkyl part and a 6- 12C aryl part optionally substituted on the aryl part with halogens or 1-3C alkyls and/or alkoxyls;Z = hydroxy, alkoxy;Poa = polyoxyalkylene ether;m = integer or real greater than 0;n = integer or real which is 2 or above or may be 0 when both R are H;o = integer or real 1 or more;q = integer or real 0 or above.More preferablym = 2-200 (most preferably 6-12);n = 2-200;o = 1-50;q = 0-10;R'-Poa = -(CH2)3-O-(CH2CH2- O)m-CH3, -(CH2)2-O-(CH2CH2-O)m-CH3, -(CH2)3-O-(CH)CH3)-CH2- O)m-CH3, -(CH2)2-O-(CH(CH3)-CH2-O)m-CH3.The second POS is of Formula (II)x' = integer or real 2 or more and optionally 0;y' = integer or real 0 or more;R'2, R''2 = 1-8C alkyl (preferably methyl, ethyl, propyl, octyl, 3,3,3-trifluoropropyl) optionally substituted with least one halogen preferably F, 5-8C optionally substituted cycloalkyl, 6-12C optionally substituted aryl, a 5-14C alkyl part and a 6-12C aryl part optionally substituted on the aryl part;when x' is 0 R2 is -OH.Preferred Catalyst: The catalyst is platinum, boron, rhodium, palladium, tin or iridium based derivative or complex. When it is tin or platinum based the proportions of first and second POS are so determined that the ratio of SiH groups/SiOH groups is 0.5-5 and more preferably 0.9-2.1. More preferably the catalyst is dibutyltin dilaurate, a Karstedt catalyst or an iridium catalyst of Formula (IV).Preferred Electrolyte Salt: The electrolyte salt is a cation: metallic cation, an ammonium, amidinium or guanidium ion or an anion: chloride, bromide, iodide, perchlorate, thiocyanate, tetrafluoroborate, nitrate, AsF6-, PF6-, stearylsulfonate, trifluoromethanesulfonate, octylsulfonate, dodecylbenzenesulfonate, R4SO3, (R4SO2), (R5SO2)N-, (R5SO2), (R6SO2)C-, whereR4, R5, R6 = an electroattractor group preferably 1-6C perfluoroaryl or perfluoroalkyl.More preferably the electrolyte comprises an alkali metal or alkaline earth metal or group 1 or 2. Most preferably the metal is lithium and the electrolyte is LiClO4, LiBF4, LiPF6, LiAsF6, LiCF3SO3, LiN(CF3SO2)2, Li(C2F5SO2)2 or a mixture of them. The amount is so chosen that the molar ratio O/Li is 15-40 and more preferably 20-25. Alternatively the metal cation is a transition metal and is manganese, iron, nickel, copper, zinc, cadmium, manganese or silver or the electrolyte is organic and is propylene-, ethylene-, diethyl-, dimethyl-, ethylmethyl carbonate, gamma- butyrolactone, 1,3-dioxolan, dimethoxyethane, tetrahydrofuran, dimethyl sulfoxide or polyethyleneglycol dimethyl ether. EXAMPLE - A first POS of structure (CH3)3SiO1/2- ((CH3SiHO2/2)22.4-((CH3)2SiHO2/2)23.4-((CH2)3-(O-CH2- CH2)8-OCH3)20-((CH3)Si(OH)O2/2)2-((CH3)SiO3/2)8.8- (CH3)3SiO1/2 with number average mol.wt. 1050 and weight average mol.wt. 5190 was prepared. A composition was prepared using this POS and a second POS oil of Formula    by mixing 10g of the first POS, 1.40g of lithium bistrifluoromethanesulfonamide, 2.47g of the second POS oil and 0.1g tributyl tin dilaurate. The mixture was brought to 70degreesC and held at that temperature for 16 hours to allow crosslinking. After cooling the polymer electrolyte was recovered in the form of a film. When measured by complex impedance spectrometry the ionic conductivity was between 10-4 and 5x10-6 Siemens/cm.