TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The anion is derived from oxo-acid chosen from multivalent oxo-acid of formula: HnXO4 (I), preferably dihydrogen phosphate anion or hydrogen sulfide anion. The molecule having proton donor property is multivalent oxo-acid (I), preferably molecule of phosphoric acid or sulfuric acid. The molecule having proton acceptor property has lone pair in the structure.n=2-4.(i) When n is 2, X is sulfur, selenium, chromium, tellurium, molybdenum or tungsten; (ii) when n is 3, X is potassium, arsenic, vanadium, niobium, manganese or antimony; and (iii) when n is 4, X is silicon or germanium.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Group: The functional group which functions as a hydrogen bond donor is hydroxyl group or amine group of formula: -NR1H. The functional group which functions as a hydrogen bond acceptor is chosen from group of formula: =O, =NR2, O-, and -NR3-.R1-R3=H or hydrocarbyl.Preferred Components: The molecule having proton donor property is acid chosen from oxo-acid, imido acid, thio acid and hydrohalic acid. The molecule having proton acceptor property is chosen from imidazole derivative, benzimidazole derivative, pyridine derivative, pyrrolidine derivative, piperidine derivative, piperazine derivative, amine derivative, phosphine derivative, acetone, acetonitrile, N,N-dimethylformamide and dimethyl sulfoxide. The cation of salt is cation derived from imidazolium derivative, benzimidazolium derivative, pyridinium derivative, pyrrolidinium derivative, piperidinium derivative, piperazinium derivative, ammonium derivative, phosphonium derivative and sulfonium derivative, preferably imidazolium derivative, and at least one of 1st position of imidazolium derivative or 3rd position is an allyl group. The molecule of cation and anion is 1-allyl-3-alkyl imidazolium-ion and dihydrogen phosphoric acid anion of formula (II). The molar ratio of phosphoric acid with respect to cation is 0-2, preferably 1. The proton-conductive electrolyte further contains molecular solvent.R4=1-20C alkyl or allyl.