Provided herein is a redox flow battery comprising an anode comprising anodic redox mediators; a negative electrolyte tank comprising an anolyte; and an anode pump capable of circulating the anolyte through the anode. The redox flow battery further comprises a cathode comprising cathodic redox mediators; a positive electrolyte tank comprising a catholyte and a cathode pump capable of circulating the catholyte through the cathode. A separator is between the anode and cathode.

Flow battery systems are provided, including flowing a liquid electrolyte from a storage tank of a flow battery system to an electrode chamber of the flow battery system, the liquid electrolyte comprising a solvent and a first active ion dissolved in the solvent, wherein the storage tank comprises the liquid electrolyte and a first solid composed of the active ion and an ion of the solvent; inducing an electrochemical reaction in the electrode chamber to convert the first active ion dissolved in the solvent to a second active ion dissolved in the solvent, wherein the first solid dissolves to provide more of the first active ion dissolved in the solvent; flowing the liquid electrolyte comprising the solvent and the second active ion dissolved in the solvent from the electrode chamber back to the storage tank; and precipitating a second solid composed of the second active ion and the ion of the solvent in the storage tank.

A high voltage metal-free battery comprising a cathode comprising a cathode electroactive material, wherein the cathode electroactive material comprises at least one of an organic compound, an oxide, a hydroxide, an oxyhydroxide, a sulfide, and combinations thereof; an anode comprising an anode electroactive material, wherein the anode electroactive material comprises at least one of an organic compound, an oxide, a hydroxide, an oxyhydroxide, a sulfide, and combinations thereof; a catholyte in contact with the cathode, wherein the catholyte is not in contact with the anode; and an anolyte in contact with the anode, wherein the anolyte is not in contact with the cathode. The catholyte has a pH of less than 4, and the anolyte has a pH of greater than 10. The battery comprises a separator, wherein the separator has ion-selective properties.

This disclosure relates to compositions and methods for improving the performance of batteries, such as lead-acid batteries, including reviving or rejuvenating a partially or totally dead battery, by adding an amount of nonionic, ground state metal nanoparticles to the electrolyte of the battery, and optionally recharging the battery by applying a voltage. The metal nanoparticles may be gold and coral-shaped and are added to provide a concentration within the electrolyte of 100 ppb to 2 ppm or more (e.g., up to 5 ppm, 10 ppm, 25 ppm, 50 ppm, or 100 ppm). The metal nanoparticles may be added to battery electrode paste applied to the electrodes to enhance newly manufactured or remanufactured batteries.

A hybrid energy storage device has at least two half cells, wherein each half cell includes an electrode comprising an electrically conductive high surface area material incorporating an electrolyte comprising a dissolved species that can exist in more than two redox states, and at least one separator that separates the at least two half cells and allows transfer of selected charge carriers between the half cells. After an initial charging, a redox pair of one half cell is different from the redox pair of the other half cell. The hybrid energy storage device operates as a battery for low power applications, and as a supercapacitor for high power applications. The hybrid energy storage device may be flexible.

A lead-acid battery is disclosed. The lead-acid storage battery has a container with a cover, the container including one or more compartments. One or more cell elements are provided in the one or more compartments. The one or more cell elements include a positive plate, the positive plate having a positive grid and a positive electrochemically active material on the positive grid; a negative plate, the negative plate having a negative grid and a negative electrochemically active material on the negative grid, wherein the negative electrochemically active material comprises barium sulfate and an organic expander; and a separator between the positive plate and the negative plate. Electrolyte is provided within the container. One or more terminal posts extend from the cover and are electrically coupled to the one or more cell elements.

A novel energy storage battery system is described that includes a highly reversible electrolytic Zn—MnO.sub.2 system in which electrodeposition/electrolysis of Zn (anode side) and MnO.sub.2 (cathode side) couple is employed with a theoretical voltage approximately 2 V and energy density of approximately 409 Wh kg.sup.−1 providing superior durability and excellent energy densities.

A flow battery field, an electrode slurry, a slurry electrode, a flow battery, and a stack are disclosed. The electrode slurry comprising electrode particles and electrolyte that contains active substance. Based on 100 pbw active substance, the electrode particles are 10-1,000 pbw. The slurry electrode comprises: a bipolar plate, a current collector, and a slurry electrode reservoir configured to store electrode slurry. In the two opposite sides of the bipolar plate, one side is adjacent to the current collector, and the other side is arranged with a slurry electrode cavity, and flow channels are arranged and extended between the bipolar plate and the slurry electrode cavity, so that the electrode slurry is circulated between the slurry electrode cavity and the slurry electrode reservoir. A flow battery that employs the electrode slurry can provide higher and more stable power output under the same current condition and is lower in cost.

An electrochemical device has an electrochemical cell provided with an electrolyte having proton conductivity, an anode provided on one side of the electrolyte, and a cathode provided on the other side of the electrolyte. The electrochemical device is configured so that a solution containing water, an artificial synthetic resin, and an acid is supplied to the anode. The electrochemical device is configured so that an oxygen-containing gas is supplied to the cathode and connecting a load between the anode and the cathode. The electrochemical device is configured so that the inert gas is supplied to the cathode and connecting the voltage application unit between the anode and the cathode.

Disclosed are an electrolytic reduction system of a vanadium electrolyte and a method for producing the electrolyte. The electrolytic reduction system includes a separating device and an electrolytic tank. The separating device is configured to separate a mixture consisting of a vanadium pentoxide (V2O5) solid and a sulfate acid solution, thereby obtaining a vanadium solution from a liquid discharging port of the separating device and a vanadium solid from a solid discharging port. The vanadium solution includes pentavalent vanadium ions. The electrolytic tank connects to the liquid discharging port of the separating device to contain the vanadium solution. In the method for producing the vanadium electrolyte, other chemical reagents are unnecessarily to be added into the mixture, and the vanadium solution is subjected to an electrolytic reduction process, such that the pentavalent vanadium ions are reduced to tetravalent vanadium ions and trivalent vanadium ions in the electrolytic tank.