TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electrolyte salt: is lithium salt; is chlorides, bromides, sulfates, nitrates, sulfides, hydrides, nitrides, phosphates, sulfonamides, triflates, thiocyanates, 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; or lithium thiocyanate, lithiated cyanamide, lithium perchlorate trihydrate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium trifluoro-methane-sulfonate, lithium bistrifluoromethylsulfonyl imide, lithium tris(trifluoromethylsulfonyl) methanide, lithium bisperfluoroethylsulfonyl imide, lithium bistrifluoromethanesulfonimidate, lithium bis(perfluoroethylsulfonyl)imide, lithium alkyl fluorophosphates, lithium oxalatoborate, and other lithium bis(chelato)borates having 5-7 membered rings, lithium bis(trifluoromethane sulfone)imide, lithium trifluorotris(pentafluoroethyl)phosphate, lithium(trifluoro tris(perfluoromethyl))phosphate and/or lithium bis(oxalate)borate.    TECHNOLOGY FOCUS - POLYMERS - Preparation: No preparation method is given. Preferred Components: The polymer and the polymer electrolyte further comprises a second pendant chain comprising a polar group, and the second pendant group is attached to the backbone. The polar group is cyano, sulfoxide, sulfonyl or ethylene carbonate. Many of alkylene oxide pendant chains and many of polar group pendant chains are attached to the backbone, and the molar ratio between the alkylene oxide pendant chains and the polar pendant chains is 98/2-70/30. The polymer has a structure comprising substituted vinyl or substituted ethylene oxide prepolymers of formula (I)-(X). The vinyl backbone can be derived from prepolymers comprising substituted vinyl derivatives of formula (XI)-(XV). The ethylene oxide backbone can be derived from prepolymers comprising substituted ethylene derivatives of formula (XVI)-(XX). The backbone has a molecular weight of 20000-500000, (preferably 50000-200000) Daltons.R = H or CH3;L = (CH2)n, O(CH2)n, (CH2)n-O(CH2)m, Ph-O(CH2)n, Ph-CH2O(CH2)n or -C(=O)-O-(CH2)n;X = S, silane or siloxane;EO = oligo-alkylene oxide; andn, m = 0-8. EXAMPLE - Poly(4-pentenyl acrylate) and 1-(3-(2-methoxy-ethoxy)-propyl)-1,1,3,3-tetramethyl-disiloxane was hydrosilylated in the presence of platinum catalyst to give a polyacrylate with ethylene oxide pendants.