The present invention provides an air battery using oxygen in air as a cathode active material, the air battery comprising: a cylindrical anode made of a metal; a cathode constituted by a co-continuous body having a three dimensional network structure formed by an integrated plurality of nanostructures having branches; and a separator that is arranged between the cathode and the anode and absorbs an electrolytic solution, wherein: the cathode is arranged inside the anode via the separator; and the anode has an open hole that reaches the separator and constitutes a housing of the air battery.

Development of a flexible battery based on periodate/iodate-zinc system is disclosed. H.sub.3PO.sub.4—KCl dual quasi-solid electrolytes separated by an anion-exchange-membrane maintain the desired pH in electrodes and block unwanted ion movements. Poly(acrylic acid) fortifies the electrodes, enhances electrode flexibility, and avoids the free-flow of liquids. The NaMnIO.sub.6 shows a specific capacity of 650 mAg.sup.−1, approximately 81% of its theoretical capacity even when cells are bent. The overall technology is scalable by printing methods.

The present invention relates to a method of preparing a high-purity electrolyte solution for a vanadium redox flow battery using a catalytic reaction, and more specifically, to a method of preparing a high-purity electrolyte solution having a vanadium oxidation state of +3 to +5 from a mixture solution containing a vanadium precursor, a reducing agent, and an acidic solution, by using a catalyst. By using a catalyst and a reducing agent that does not leave impurities such as Zn.sup.2+, which are generated when preparing electrolyte solutions using an existing metal reducing agent, the high-purity electrolyte solution for a vanadium redox flow battery (VRFB) according to the present invention eliminates the need for an additional electrolysis process; does not form toxic substances during a reaction process, and thus is environmentally friendly; and is electrochemically desirable under milder process conditions than that of an existing process. In addition, the VRFB comprising the electrolyte solution prepared according to the present invention may be used to expand the utility of new renewable energy through price reduction of large-capacity energy storage devices.

An exemplary method of providing an electrolyte for a fuel cell comprises including a electrolyte precursor within a fuel cell. An electrolyte is generated within the fuel cell from the precursor. An exemplary fuel cell system includes a cell stack assembly. A manifold is associated with the cell stack assembly. An electrolyte precursor is within at least one of the cell stack assembly or manifold for generating an electrolyte within a fuel cell.

A secondary battery having high electromotive force and including less lead or being free of lead is provided. The secondary battery includes a positive electrode including a positive electrode active material containing manganese oxide, a negative electrode including a negative electrode active material containing at least one selected from zinc, gallium, and tin, and an electrolytic solution containing at least one selected from phosphoric acid and organic oxoacid and having a pH of less than 7 at 25° C. This secondary battery has an open circuit voltage of more than 1.6 V in a fully charged state.

Provided is an electrolyte for a flow battery, the electrolyte being supplied to a flow battery, in which a total concentration of ions of elements of groups 1 to 8 and ions of elements of groups 13 to 16 in the fifth period of the periodic table, and ions of elements of groups 1, 2, and 4 to 8 and ions of elements of groups 13 to 15 in the sixth period of the periodic table, the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, is 610 mg/L or less, a concentration of vanadium ions is 1 mol/L or more and 3 mol/L or less, a concentration of free sulfuric acid is 1 mol/L or more and 4 mol/L or less, a concentration of phosphoric acid is 1.0×10.sup.−4 mol/L or more and 7.1×10.sup.−1 mol/L or less, a concentration of ammonium is 20 mg/L or less, and a concentration of silicon is 40 mg/L or less. When a charging and discharging test is performed by circulating and supplying the electrolyte to the flow battery under specific conditions, a generation rate of hydrogen is less than 10 cc/h/m.sup.2 and a generation rate of hydrogen sulfide is less than 5.0×10.sup.−3 cc/h/m.sup.2, the hydrogen and the hydrogen sulfide being generated in a negative electrode of the flow battery during charging and discharging.

A raw material of an electrolyte solution that is to be dissolved in a solvent to form an electrolyte solution, and the raw material of an electrolyte solution is a raw material of an electrolyte solution that is a solid or semisolid that contains Ti in an amount of 2 mass % to 83 mass % inclusive, Mn in an amount of 3 mass % to 86 mass % inclusive, and S in an amount of 6 mass % to 91 mass % inclusive.

Provided is an electrolyte for a flow battery, the electrolyte being supplied to a flow battery, in which a total concentration of ions of elements of groups 1 to 8 and ions of elements of groups 13 to 16 in the fifth period of the periodic table, and ions of elements of groups 1, 2, and 4 to 8 and ions of elements of groups 13 to 15 in the sixth period of the periodic table, the ions being impurity element ions involved in generation of a gas containing elemental hydrogen, may be 610 mg/L or less and a concentration of vanadium ions may be 1 mol/L or more and 3 mol/L or less.

An inorganic compound for a Li-ion conductor includes an oxyhalide compound with a chemical composition of MOX where M is at least one of Al, Sc, La, and Y, and X is at least one of F, Cl, Br, and I. Also, the oxyhalide compound has a thermal decomposition start temperature of the oxyhalide compound is greater than a thermal decomposition start temperature of FeOCl and a conductivity that is general equal to or greater than a conductivity of the FeOCl.

An inorganic compound for a Li-ion conductor includes an oxyhalide compound with a chemical composition of MOX where M is at least one of Al, Sc, La, and Y, and X is at least one of F, Cl, Br, and I. Also, the oxyhalide compound has a thermal decomposition start temperature of the oxyhalide compound is greater than a thermal decomposition start temperature of FeOCl and a conductivity that is general equal to or greater than a conductivity of the FeOCl.