A reservoir for a redox flow battery comprising: at least one inner tank for electrolyte, the or each inner tank having at least one inner tank wall, an outer, bund tank around the or each inner tank, air circulation gaps or passages between the inner and outer walls or the inner and outer tanks and means for passing cooling air to the air circulation gaps or passages for cooling the electrolyte in or each inner tank.

A reservoir for a redox flow battery comprising: at least one inner tank for electrolyte, the or each inner tank having at least one inner tank wall, an outer, bund tank around the or each inner tank, air circulation gaps or passages between the inner and outer walls or the inner and outer tanks and means for passing cooling air to the air circulation gaps or passages for cooling the electrolyte in or each inner tank.

A battery bank for a redox flow battery having a cavity in which electrolyte is stored, wherein the electrolyte is provided for supply to one or more redox flow cells, characterized in that the cavity is a cavern.

A battery bank for a redox flow battery having a cavity in which electrolyte is stored, wherein the electrolyte is provided for supply to one or more redox flow cells, characterized in that the cavity is a cavern.

A system comprises a first electrode, an electrolyte membrane, and a second electrode. The first electrode is configured to reduce oxygen in a gas to an oxygen carrier ion at an intermediate temperature. The electrolyte membrane is configured to transport the oxygen carrier ion, and the second electrode is configured to oxidize the oxygen carrier ion to an oxygen molecule. Oxidation of the oxygen molecule consumes less than four electrons.

A system comprises a first electrode, an electrolyte membrane, and a second electrode. The first electrode is configured to reduce oxygen in a gas to an oxygen carrier ion at an intermediate temperature. The electrolyte membrane is configured to transport the oxygen carrier ion, and the second electrode is configured to oxidize the oxygen carrier ion to an oxygen molecule. Oxidation of the oxygen molecule consumes less than four electrons.

Disclosed is a porous support including fine porous structures formed between nanofibers, wherein the fine porous structures have a porosity of 50% to 90%, a pore size of 0.01 μm to 10 μm and an air permeability of 0.01 to 7 sec/100 cc.Math.air, and the porous support has a thickness of 5 μm to 50 μm, a method of manufacturing the same and a reinforced membrane including the same.

Disclosed is a porous support including fine porous structures formed between nanofibers, wherein the fine porous structures have a porosity of 50% to 90%, a pore size of 0.01 μm to 10 μm and an air permeability of 0.01 to 7 sec/100 cc.Math.air, and the porous support has a thickness of 5 μm to 50 μm, a method of manufacturing the same and a reinforced membrane including the same.

A method of cleaning power cells in an array of power cells, comprising coupling at least one first power cell to second power cells in an array of power cells and causing the second power cells to drive the at least one first power cell with a voltage to clean catalyst on the at least one first power cell.

A method of cleaning power cells in an array of power cells, comprising coupling at least one first power cell to second power cells in an array of power cells and causing the second power cells to drive the at least one first power cell with a voltage to clean catalyst on the at least one first power cell.