TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Battery: The anode is selected from carbonaceous material, metal, metalloid and metalloid-containing alloy, and has reduction potential versus lithium potential of 0-1V. The secondary battery has charge/discharge voltage of up to 4.35V. Preferred Method: The EDG is introduced into the N-position of the amide group containing compound, to intrinsically shift the electrochemical stability window of the eutectic mixture to lower limit.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The eutectic mixture has decrease in reduction potential, caused by introducing the EDG. The EDG has Hammett substituent constant value of less than 0. The electrolyte additionally comprises first compound that reduced at potential higher than reduction potential versus lithium potential (Li/Li+) of the eutectic mixture to form a passivation film; and/or second compound having an oxidation potential higher than cathode potential and thus consuming overcharge current. The electrolyte is formed by either polymerizing an electrolyte precursor solution containing the eutectic mixture, and monomers that form a gel polymer via polymerization; impregnating polymer or gel polymer with eutectic mixture; or dissolving polymer and the eutectic mixture in solvent, and then removing the solvent. Preferred Components: An anion of the lithium salt is selected from F, Cl, Br, I, NO3, N(CN)2, BF4, ClO4, PF6, (CF3)2PF4, (CF3)3PF3, (CF3)4PF2, (CF3)5PF, (CF3)6P, CF3SO3, CF3CF2SO3, (CF3SO2)2N, (FSO2)2N, CF3CF2(CF3)2CO, (CF3SO2)2CH, (SF5)3C, (CF3SO2)3C, CF3(CF2)7SO3, CF3CO2, CH3CO2, SCN and (CF3CF2SO2)2N.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The amide group-containing compound is of formula (R1)m-X-C(O)-N(R2)(R3) or compound of formula (II).R2 and R3=EDG, H or halo;X=H, C, Si, O, N, P or S;X'=C, Si, O, N, P or S;R1 and R4= H, halo, 1-20C alkyl, alkylamine, alkenyl or aryl;m=0-3;s=0-2;n=1-10;R5=EDG.Provided that(A) at least one of R2 and R3 is EDG, and other is H or halo;(B) when X is H, then m is 0;(C) when X is O or S, then m is 1;(D) when X is N or P, then m is 2;(E) when X is C or Si, then m is 3;(F) when X' is O or S, then s is 0;(G) when X' is N or P, then s is 1; and when X' is C or Si, then s is 2. SPECIFIC COMPOUNDS - 14 Compounds are specifically claimed as the amide group-containing compound, e.g. N-ethylacetamide, N-methylurea, N,N'-dimethyl urea, ethyl N-methylcarbamate (I') and ethyl N-ethylcarbamate.    EXAMPLE - An eutectic mixture (test) (13 g) was obtained by mixing ethyl N-methylcarbamate (CH3NHCOOC2H5) (7 g) and LiN(SO2CF3)2 (6 g) in molar ratio of 3:1, and then gradually stirring the resultant mixture at room temperature under nitrogen atmosphere for 12 hours. Subsequently, moisture contained in the eutectic mixture was reduced to less than or equal to 20 ppm under vacuum atmosphere of 0.3 torr. A comparative (control) eutectic mixture was prepared in similar manner of the test mixture except using ethylcarbamate (6 g) instead of 7 g of ethyl N-methylcarbamate. Both test/control mixtures were evaluated for reduction potential and it was found to be that the test mixture showed reduction potential of 0.3V, whereas the control showed reduction potential of 0.55V. Hence the test mixture is used as a component of an electrolyte and the electrochemical stability window of the electrolyte was shift to a lower limit.