A reduction-oxidation flow battery wherein the catholyte and/or the anolyte are selected from among respective defined groups of polyoxometalate compounds.

An aqueous electrolyte composition suitable for a lithium ion battery is provided. The aqueous electrolyte composition contains water, an ionic liquid which is a salt of a protonic cation and an anion comprising a fluoroalkylsulfonyl group and a lithium fluoroalkylsulfonyl salt. A lithium ion battery containing the aqueous electrolyte and a vehicle at least partially powered by the battery are also provided.

An illustrative example fuel cell component includes an electrode substrate including a plurality of pores. A first portion of the substrate includes a liquid electrolyte absorbing material in at least some of the pores in the first portion. Those pores respectively have a first unoccupied pore volume. Pores in a second portion of the substrate respectively have a second unoccupied pore volume. The first unoccupied pore volume is less than the second unoccupied pore volume.

Disclosed is an aqueous battery, in which not only a predetermined aqueous electrolyte solution is adopted, but also an ionic conduction path between positive and negative electrodes is ensured. The aqueous battery of the present disclosure includes a positive electrode, an aqueous electrolyte solution, a separator and a negative electrode, in which the aqueous electrolyte solution contains water and a potassium salt dissolved in the water, the aqueous electrolyte solution has no freezing point at ?60? C. or higher, and at least one element constituting the separator is the same in type as at least one element constituting an anion of the potassium salt.

The present disclosure relates to a metal-air battery, such as a zinc (Zn)-air battery with a decoupled cathode, an acidic catholyte, an alkaline anode electrolyte, and a solid electrolyte between the catholyte and the anode electrolyte.

The aqueous secondary battery of the present disclosure comprises: a positive electrode active material layer, an aqueous electrolyte, and a negative electrode active material layer, wherein the aqueous electrolyte contains an aqueous solvent and potassium polyphosphate which has two or more elemental phosphorus, and any one of potassium ion, proton, hydroxide ion, and polyphosphoric anion is a carrier ion, a positive electrode active material contained in the positive electrode active material layer has a monoclinic crystal structure represented by space group C2/m, is represented by composition formula MnO.sub.2.Math.A.sub.xB.sub.y(H.sub.2O).sub.z, and the A, B, and H.sub.2O are present in a space interposed between layers composed of MnO octahedrons, A is an alkali metal or alkali rare earth metal, B is an anion, 0<x<1, 0<y<1, and 0<z<2.

A redox flow battery includes a battery cell including a positive electrode, a negative electrode, and a membrane disposed between these two electrodes; a positive electrode electrolyte supplied to the positive electrode; and a negative electrode electrolyte supplied to the negative electrode, wherein the positive electrode electrolyte contains manganese ions and a phosphorus-containing substance, the negative electrode electrolyte contains at least one species of metal ions selected from titanium ions, vanadium ions, chromium ions, and zinc ions, and a concentration of the phosphorus-containing substance is 0.001 M or more and 1 M or less.

A solid electrolyte includes an amorphous silica network and phosphoric acid. The phosphoric acid is contained in the amorphous silica network, and is typically in molecular form. The ratio of silicon to phosphorus in the solid electrolyte is about 1:4, and the silicon is in a four-coordinated state. The solid electrolyte is in the form of a dried (e.g., anhydrous) gel. The solid electrolyte may be used in a fuel cell membrane. Preparing the solid electrolyte includes reacting phosphoric acid in the liquid state with tetrachloride compound including silicon and a displaceable ligand to yield a fluid suspension, heating the fluid suspension to yield a liquid electrolyte comprising a particulate solid, separating the particulate solid from the liquid electrolyte, combining the particulate solid with water to yield a homogenous solution, forming a gel from the homogeneous solution, and removing water from the gel to yield the solid electrolyte.

An illustrative example fuel cell electrolyte management device includes a first component having a first density and a second component having a second density that is less than the first density. The first component has a first side including a pocket and a second side facing opposite the first side. The second side of the first component includes a first plurality of fluid flow channels. The second component has a porosity configured for storing electrolyte in the second component. The second component fits within the pocket. The second component has a first side received directly against the first side of the first component. The second component has a second side including a second plurality of fluid flow channels.

A positive electrode active material includes a nickel-containing lithium transition metal oxide containing nickel in an amount of 60 mol % or more based on a total number of moles of transition metals excluding lithium, and a lithium-containing inorganic compound layer formed on a surface of the nickel-containing lithium transition metal oxide, wherein the positive electrode active material has a first peak in a range of 5 eV or less, a second peak in a range of 7 eV to 13 eV, and a third peak in a range of 20 eV to 30 eV when intensity is measured by X-ray photoelectron spectroscopy, and the first peak has a maximum value of 80% to 120% with respect to the third peak. A method of preparing the positive electrode active material, and a positive electrode and a lithium secondary battery are also provided.