TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The backbone in (A) is poly(meth)acrylate. Hydrophilic grafts comprise oligo(ethylene oxide) chains. Hydrophobic grafts comprise fluorinated alkyl/aryl chains or 8C alkyl chains. (A) is of formula ((CH2C(CH3)(C(O)OR2))z(CH2C(CH3)(C(O)OCH3))v(CH2C(CH3)(C(O)(O(CH2CH2O)nR1)y)xz, y and v = integer corresponding to composition (wt.%) z = 5-90 (preferably 10-80);y = 5-95 (preferably 10 - 90);v = 0-90 (preferably 0 - 50);n = 5-35;R1 = 1-5C alkyl; andR2 = fluorinated 1-20C alkyl (preferably 1-10C alkyl).(B) is a lithium salt and is selected from lithium hexafluorophosphate, lithium hexafluoroarsinate, lithium tetrafluoroborate, lithium chlorate, lithium ditriflylamide, lithium triflate, lithium perfluoropropanesulfonate and lithium 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-octadecafluorodecane sulfonate.Preferred Electrolyte: (I) is a crosslinked polymer and is either a polymeric gel containing at least one plasticizer or a solvent or is a solid polymer without any plasticizer or the solvent. EXAMPLE - To a mixture of poly (ethylene glycol), monomethyl ether methacrylate (3.3. g), methyl methacrylate (1.1 g) and 1H,1H,7H-dodecafluoroheptyl methacrylate (6.5 g)in toluene (100 ml) under inert atmosphere azobisisobutyronitrile (AIBN) (0.13 g) was added and radical copolymerisation was carried out at 60degreesC for 15 hours. The mixture was then filtered. The graft copolymer was first precipitated in n-hexane dried and dissolved in tetrahydrofuran (THF). A second precipitation was carried out in methanol and the precipitate was leached with distilled water. The synthesized amphiphilic graft copolymer (A) consisted (wt.%): poly(ethylene glycol) monomethyl ether methacrylate (32), methyl methacrylate (10) and 1H,1H,7H-dodecafluoroheptyl methacrylate (58). LiPF6 in ethylene carbonate and gamma-butyro lactone (2:1 by weight) was dissolved in a concentration of 1 mole per liter of the solvent. In this solution (A) (30 wt.%) was dissolved to give a test sample of the homogenous polymer gel electrolyte. A comparative sample was prepared using same electrolytic solution with poly(methyl methacrylate) (30 wt.%). The results of the test/comparative on the ionic conductivity (mS/cm) were = 2.5/1.2 (at 20degreesC); 3.2/1.7 (at 30degreesC).