NOVELTY - A nonflammable solid polymer electrolyte or matrix (SPE or PME) composition comprising at least one ring-nitrogen substituted alkyl and/or fluoroalkyl lithium sulfonate polyazole polymer and/or hydroxyethylated polyazole polymer, and optionally at least one lithium salt, at least one solvent or ionic liquid. The polyazole polymer, lithium salt and solvent and/or ionic liquid form a composition that is homogeneous and optically clear, and can be made nonflammable.    USE - As a solid electrolyte for use in a battery and in a supercapacitor (claimed); in polymer electrolyte battery assemblies; in consumer automotive applications; and as separator-membranes in high performance lithium and lithium ion batteries.    ADVANTAGE - The polymer has very high thermal/chemical stability; is optical clear; can be made completely nonflammable; shows uniquely high lithium ion transfer values, high current carrying capacity over a wide temperature range, excellent rechargeability, and good compatibility with anode and cathode materials; and possesses high lithium conductivity over a broad temperature range, high energy density and operating current, charge cycle durability, broad voltage range and high output voltage and current, good current carrying capability and good membrane mechanical integrity.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the polymer (SPE or PME) composition involving a) preparing a solution of a polybenzimidazole polymer in at least one solvent comprising ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, 1,2-dimethyl ether, 1,2-diethyl ether, gamma-butyrolactone, acetonitrile, dimethyl formamide and dimethyl sulfoxide; b) heating the solution to form a solution of partially or completely hydroxyethylated polybenzimidazole; c) drying the solution to form a partially or completely hydroxyethylated polybenzimidazole solution; d) mixing the partially or completely hydroxyethylated polybenzimidazole solution with lithium hydride to produce a solution of the corresponding polybenzimidazole polyanion or mixture of polybenzimidazole polyanions; e) reacting the resulting hydroxyethylated polybenzimidazole polyanion solution with a perfluorinated sultone; f) optionally adding at least one lithium salts selected from LiCl, LiBr, Lil, LiSCN, LiClO4, LiBF4, LiAsF6, LiSO3CF3, LiSbF6, LiPF6, LiCF3SO2, LiAlO4, LiNO3, LiB(Ph)4, LiCH3CO2, LiCF3CO2, LiAlCl4 and/or LiN(SO2CF3)2; and g) casting the solution of step e) or f) onto a substrate with partial or complete evaporation of the solvent(s).