TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Salt: The salt is lithium salt. The salt is selected from chlorides, bromides, sulfates, nitrates, sulfides, hydrides, nitrides, phosphates, sulfonamides, triflates, thiocynates, perchlorates, borates, or selenides of lithium, sodium, potassium, copper, silver, zinc, barium, lead, magnesium, calcium, ruthenium, tantalum, rhodium, iridium, cobalt, nickel, molybdenum, tungsten or vanadium. The salt is selected from LiSCN, LiN(CN)2, LiClO4, LiBF4, LiAsF6, LiPF6, LiCF3SO3, Li(CF3SO2)2N, Li(CF3SO2)3C, LiN(SO2C2F5)2, LiN(SO2CF3)2, LiN(SO2CF2CF3)2, lithium alkyl fluorophosphates, lithium oxalatoborate, and other 5 to 7 membered ring of lithium bis(chelato)borates, lithium bis(trifluoromethane sulfone imide) (LiTFSI), LiPF3(C2F5)3, LiPF3(CF3)3 and/or LiB(C2O4)2.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The oligomeric alkylene oxide group is selected from crown ethers, ethylene oxides, trimethylene oxides, and their corresponding fluorinated derivatives. The polar group is selected from nitriles, perfluorocarbons, alkyl carbonates, cyclic carbonates, nitro, n-succinimide, sulfolane, phthalimide, and sulfonyl, and sulfonic acids.    TECHNOLOGY FOCUS - POLYMERS - Preparation: No general method for the preparation of the polymer (P1) is given. Preferred Compound: The polymer (P1) further comprises a second oligomeric alkylene oxide group in the first pendant chain. The polymer (P1) further comprises a several oligomeric alkylene oxide group in the first pendant chain, where there are 2-20 oligomeric alkylene oxide groups in the first pendant chain. The polymer (P1) further comprises a second pendant chain attached to the backbone polymer, where the second pendant chain comprises either an alkylene oxide group or a polar group. The polymer (P1) further comprises a third pendant chain attached to the backbone polymer, where the third pendant chain comprises either an alkylene oxide group or a polar group and is different from the second pendant chain. The polymer comprises: a backbone; and several pendant chains attached to the backbone, where the several pendant chains comprises first pendant chains containing both a first oligomeric alkylene oxide group and a first polar group, second pendant chains containing a second oligomeric alkylene oxide group, and third pendant chains comprising a second polar group. Preferred Components: The backbone has a composition selected from vinyl polymers, acrylic or methacrylate polymers, ethylene oxide polymers, polyphosphazene, polynorbornene, polysiloxanes and condensation polymers, such as polyester, polyurethane, polyimide, and polyurea. The backbone has a structure selected from linear or branched homopolymer structures, linear or branched block copolymer structures, dendrimers, rings, cages, and cross-linked molecules. The backbone polymer in the polymer electrolyte has a molecular weight of 1000-500000 (preferably 50000-400000) Daltons. EXAMPLE - No suitable example given.