TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Liquid: The anion component of the ionic liquid is chosen from an inorganic halide anion, a perhalogen acid anion, an imide anion and a methide anion. The inorganic halide anion is PF6-, BF4- or AlCl4-. The perhalogen acid anion is ClO4-, the imide anion is (C2F5SO2)2N-(BETI) or (CF3SO2)2N-, and the methide anion is (CF3SO2)3C-. The cation component of the ionic liquid is chosen from a dialkyl imidazolium ion, a trialkyl imidazolium ion, a tetraalkyl ammonium cation and an alkyl pyridinium cation. The dialkyl imidazolium ion is 1-methyl-3-ethylimidazolium, the trialkyl imidazolium ion is 1,2-dimethyl-3-propylimidazolium, the tetraalkyl ammonium cation is dimethyl ethyl methoxy ammonium, and the alkyl pyridinium cation is butyl pyridinium. EXAMPLE - Poly(2,2,6,6-tetramethyl piperidine methacrylate) (in g) (10) obtained by reacting 2,2,6,6-tetramethyl piperidine methacrylate monomer, dry tetrahydrofuran and azobisisobutyronitrile, was dissolved in dry dichloromethane (100 ml). Dichloromethane solution (100 ml) of m-chloro perbenzoic acid (15.2) was added after 1 hour, and stirred at room temperature. The m-chloro perbenzoic acid was separated by filtration and removed, and dichloromethane was distilled from filtrate after washing with sodium carbonate aqueous solution and water. Remaining solid content was ground, washed with diethyl carbonate, and dried under reduced pressure to obtain blackish brown powder of poly(2,2,6,6-tetramethyl piperidinoxyl radical methacrylate) (PTMA) (7.2) with yield of 68.2%. The obtained compound (PTMA) (600 mg), carbon black powder (1200 mg) and polytetrafluoro ethylene resin binder (100 mg), were mixed, pressurized, dried at 80 degrees C under vacuum, cut to a length of 52 mm and width of 70 mm, and molded to obtain anode. Lithium-BETI was dissolved with respect to 1-methyl-3-ethylimidazolium imide salt. The concentration of lithium-BETI was adjusted to 10 mass%, and electrolyte liquid was obtained. The obtained anode and the obtained electrolyte liquid were used to obtain the electrical storage device. The obtained electrical storage device had high energy density and high output.