The present invention is directed to a redox flow battery comprising at least one electrochemical cell in fluid communication with a balancing cell, said balancing cell comprising: a first and second half-cell chamber, wherein the first half-cell chamber comprises a first electrode in contact with a first aqueous electrolyte of the redox flow battery; and wherein the second half-cell chamber comprises a second electrode comprising a catalyst for the generation of O.sub.2; and wherein the second half-cell chamber does not contain an aqueous electrolyte.

A method of rebalancing electrolytes in a redox flow battery system comprises directing hydrogen gas generated on the negative side of the redox flow battery system to a catalyst surface, and fluidly contacting the hydrogen gas with an electrolyte comprising a metal ion at the catalyst surface, wherein the metal ion is chemically reduced by the hydrogen gas at the catalyst surface, and a state of charge of the electrolyte and pH of the electrolyte remain substantially balanced.

A plant includes a fuel supply line for supplying high-pressure fuel gas; and at least one expander disposed in the fuel supply line and configured to extract power from the high-pressure fuel gas by expanding the high-pressure fuel gas.

A method of rebalancing electrolytes in a redox flow battery system comprises directing hydrogen gas generated on the negative side of the redox flow battery system to a catalyst surface, and fluidly contacting the hydrogen gas with an electrolyte comprising a metal ion at the catalyst surface, wherein the metal ion is chemically reduced by the hydrogen gas at the catalyst surface, and a state of charge of the electrolyte and pH of the electrolyte remain substantially balanced.

The nitrogen battery of the present disclosure includes a positive electrode that uses nitrogen as a positive electrode active material, a negative electrode, and an ion conducting medium that contains a silane compound and conducts alkali metal ions.

The present invention discloses a method for preparing a vanadium battery electrolyte by using a waste vanadium catalyst. The method includes step A: soaking a waste vanadium catalyst in an oxalic acid solution for 2-8 h, to generate a solution containing vanadyl oxalate; step B: cleaning the waste vanadium catalyst, and collecting the vanadyl oxalate solution; and step C: adding a polyacid ester into the vanadyl oxalate solution; and after full reaction, removing impurities by filtration, and concentrating the filtrate to obtain a vanadyl oxalate mother solution. The method for preparing a vanadium battery electrolyte by using a waste vanadium catalyst according to the present invention does not generate wastes which cause environmental pollution in the treatment process, and can make a solution in the waste vanadium catalyst treatment process generate the electrolyte for preparing a vanadium battery. The process is simple and the treatment cost is low.

A method and a system of generating electrical power or hydrogen from thermal energy is disclosed. The method includes separating, by a selectively permeable membrane, a first saline solution from a second saline solution, receiving, by the first saline solution and/or the second saline solution, thermal energy from a heat source, and mixing the first saline solution and the second saline solution in a controlled manner, capturing at least some salinity-gradient energy as electrical power as the salinity difference between the first saline solution and the second saline solution decreases. The method further includes transferring, by a heat pump, thermal energy from the first saline solution to the second saline solution, causing the salinity difference between the first saline solution and the second saline solution to increase. The method and system may include a regeneration process, such as membrane distillation, forward osmosis, electrodialysis, salt evaporation and/or salt decomposition for further energy efficiency and power generation.

A method is provided for restoring an electrolyte of vanadium (V) redox flow battery (VRFB). Electrolyte data of an original system are analyzed in advance. A reusable positive electrode is further equipped with a V electrolyte. A reductant for a stack of VRFB is used in coordination as an electrolysis device. After a long-term reaction with a VRFB having a high valence (greater than 3.5), an electrolyte at the positive electrode is directed out to a negative electrode of the electrolysis device; and, then, electrolysis is processed after accurate calculation. In the end, the internal fluid balancing method of the original system is combined. Thus, a harmless and quick valence restoration is processed for the electrolyte of the original system, which is a final resort for the restoration of V electrolyte.

A method of the type where a brine solution is converted to an alkali metal hydroxide solution within a diaphragm cell, and the resulting cell liquor from the diaphragm cell is introduced to one or more fuel cells for the conversion of the alkali metal hydroxide to form electricity, the improvement comprising regulating the conversion of alkali metal hydroxide within the fuel cell to a conversion of less than 90%, and then subsequently concentrating the alkali metal hydroxide concentration from the anolyte stream of the fuel cell.

An apparatus and process are provided for electricity production and high-efficiency trapping of carbon dioxide, using carbon dioxide within combustion exhaust gas and converging technologies associated with a carbon dioxide absorption tower and a generating device using ions which uses a difference in concentration of salinity between seawater and freshwater. It is expected that enhanced electrical energy production efficiency, an effect of reducing costs for the operation of a carbon dioxide trapping process, and electricity production from carbon dioxide, which is a greenhouse gas, can be simultaneously achieved by increasing the difference in concentration using an absorbent for absorbing carbon dioxide.