TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compounds: The non-aqueous metal salt electrolyte may be lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium hexafluoroantimonate (LiSbF6), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium tetrachlorogallate (LiGaCl4), lithium nitrate (LiNO3), lithium thiocyanate (LiSCN), or lithium fluorosulfate (LiSO3F).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The barbituric acid is of formula (IV).R4, R5=H, CH3, C2H5, C6H5, CH(CH3)2, CH2CH(CH3)2, CH2CH2CH(CH3)2, or -CH(CH3)-CH2-CH2-CH3.The unsaturated compound (I) may be bis((4-((vinyloxy)methyl)cyclohexyl)methyl)terephthalate, triallyl trimellitate, tetra(ethylene glycol) diacrylate, triethylene glycol dimethacrylate, bis(4-(vinyloxy)butyl)succinate or bis(4-(vinyloxy)butyl)isophthalate. The non-aqueous metal salt electrolyte may be lithium tris(trifluoromethanesulfonyl)methide (LiC(SO2CF3)3), lithium bis(trifluoromethanesulfonyl)imidate (LiN(SO2CF3)2), lithium tetraphenylborate (LiB(C6H5)4), lithium pentafluorophenylsulfonate (LiC6F5SO3), lithium trifluoromethanesulfonate (LiCF3SO3), or organolithium compound (LiO3SCF2CF3 or LiO2CCF3). The non-protonic solvent comprises a higher dielectric constant and higher viscosity solvent and a lower dielectric constant and lower viscosity solvent. The higher dielectric constant and higher viscosity solvent is ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, dipropyl carbonate, acid anhydride, N-methylpyrrolidone, N-methyl acetamide, N-methyl formamide, dimethyl formamide, gamma -butyrolactone, acetonitrile, dimethyl sulfoxide, or dimethyl sulfite. The lower dielectric constant and lower viscosity solvent is 1,2-diethoxyethane, 1,2-dimethoxyethane, 1,2-dibutoxyethane, tetrahydrofuran, 2-methyl tetrahydrofuran, propylene oxide, methyl acetate, ethyl acetate, methyl butyrate, ethyl butyrate, methyl propionate, ethyl propionate, dimethyl carbonate (DMC), diethyl carbonate (DC), ethyl methyl carbonate (EMC), or propyl acetate (PA). The free radical initiator is ketone peroxide, peroxy ketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxy ester, or azo compound. It is preferably 2,2-azobisisobutyronitrile (AIBN), phenylazotriphenylmethane, t-butyl peroxide (TBP), cumyl peroxide, acetyl peroxide, benzoyl peroxide (BPO), lauroyl peroxide, t-butyl hydroperoxide, (bis(4-tert-butylcyclohexyl)peroxydicarbonate) (BCHPC), or t-butylperbenzoate. The gel polymer electrolyte precursor further comprises a passive film-type additive, preferably vinylene carbonate, sulfite, sulfate, phosphonate or derivatives.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The gel polymer electrolyte precursor comprises 1-50 wt.% bismaleimide monomer or bismaleimide oligomer, 1-50 wt.% unsaturated compound of formula (I), 0.5-2 M non-aqueous metal salt electrolyte in non-protonic solvent, 2-90 wt.% non-protonic solvent, and 0.1-10 wt.% free radical initiator, based on the sum of the bismaleimide monomer or bismaleimide oligomer and (I). Preferred Monomers: The bismaleimide monomer is of formula (II) or (III).R2=-RCH2-(alkyl), -RNH2R-, -C(O)CH2-, -CH2OCH2-, -C(O)-, -O-, -O-O-, -S-, -S-S-, -S(O)-, -CH2S(O)CH2-, -(O)S(O)-, -C6H5-, -CH2(C6H5)CH2-, -CH2(C6H5)(O)-, or optionally (di)phenylene;R3=-RCH2-, -C(O)-, -C(CH3)2-, -O-, -O-O-, -S-, -S-S-, -(O)S(O)-, or -S(O)-; andR=H or 1-4C alkyl.It is N,N'-bismaleimide-4,4'-diphenylmethane, (1,1'-(methylenedi-4,1-phenylene)bismaleimide), (N,N'-(1,1'-biphenyl-4,4'-diyl)bismaleimide), (N,N'-(4-methyl-1,3-phenylene)bismaleimide), (1,1'-(3,3'-dimethyl-1,1'-biphenyl-4,4'-diyl)bismaleimide), N,N'-ethylenedimaleimide, (N,N'-(1,2-phenylene)dimaleimide), (N,N'-(1,3-phenylene)dimaleimide), N,N'-thiodimaleimide, N,N'-dithiodimaleimide, N,N'-ketonedimaleimide, N,N'-methylene-bis-maleinimide, bis-maleinimidomethyl-ether, (1,2-bis(maleimido)-1,2-ethanediol), N,N'-4,4'-diphenylether-bis-maleimide, or (4,4'-bis(maleimido)diphenylsulfone). Preferred Polymers: The unsaturated compound (I) may be polyethylene glycol dimethacrylate. The gel polymer electrolyte precursor further comprises a thickening agent, preferably poly(vinylidenefluoride) (PVdF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), poly(vinylidene carbonate) (PVdC), polyacrylonitrile (PAN), poly(vinyl chloride) (PVCA), poly(vinyl sulfone) (PVS), poly(p-phenylene terephthalamide) (PPTA), poly(vinyl pyrrolidone) (PVP), polyethylene glycol diacrylate, or polyvinylene carbonate. Preferred Definitions:    X=-(OCH2CH2)m-(OCH2CH(CH3))n-(OCH2CH2CH2)o-O or polyethylene glycol or polypropylene glycol with a molecular weight greater than 300; and    m, n=greater than 1.    EXAMPLE - A gel polymer electrolyte precursor comprising a bismaleimide oligomer with a 10:1 ratio of 1,1-methylenedi-4,1-phenylene bismaleimide and barbituric acid (MBMI1-10) and electrolyte (1.1 M lithium hexafluorophosphate and ethylene carbonate/diethylene carbonate/propylene carbonate in a ratio of 2:3:5) in a ratio of 3.5:96.5 and bis(4-tert-butylcyclohexyl)peroxydicarbonate (BCHPC) and MBMI1-10 in a ratio of 1:10 was prepared into a soft-gel electrolyte after heating at 90 degrees C for 1 hour.