A redox flow battery includes a redox flow cell and a supply and storage system external of the redox flow cell. The supply and storage system includes first and second electrolytes for circulation through the redox flow cell. The first electrolyte is a liquid electrolyte having electrochemically active manganese species with multiple, reversible oxidation states in the redox flow cell. The electrochemically active manganese species may undergo reactions that cause precipitation of manganese oxide solids. The first electrolyte includes an inhibitor that limits the self-discharge reactions. The inhibitor includes an oxoanion compound.

The present invention relates to novel lignin-derived compounds and compositions comprising the same and their use as redox flow battery electrolytes. The invention further provides a method for preparing said compounds and compositions as well as a redox flow battery comprising said compounds and compositions. Additionally, an assembly for carrying out the inventive method is provided.

The present invention relates to a flow battery system. The system comprises a first and second electrode comprising a lattice structure and at least one electrolyte supply configured to provide flow electrolyte through at least one of the first and second electrodes. A power circuit is operatively connected to the first and second electrodes to provide electrical power from the system.

The invention relates to an electrode (1) for a flow battery (B) and a method for producing said electrode (1), wherein said electrode (1) comprises a first portion (12) consisting of particles (11) of electrically conductive material having nanometric dimensions, wherein said first portion (12) is mesoporous and its porosity is such as to increase the quantity of redox reactions per time unit in a flow of an electrolytic solution of said battery (B).

A protective layer for an electrolyte in a flow battery and an electrolyte tank having a protective layer. The protective layer includes a light oil that includes hydrophobic hydrocarbons. The light oil having a density lower than a density of the electrolyte, the hydrophobic hydrocarbons being non-reactive to the electrolyte. The protective layer may be a liquid layer or may include a substrate impregnated with the light oil. An inert gas may also be utilized in the electrolyte tank.

Various embodiments include a method for operating an electrically rechargeable redox flow battery comprising: using a redox flow battery having a first chamber and a second chamber separated by a membrane, wherein the first chamber comprises a cathode and the second chamber comprises an anode; conducting a first electrolyte as catholyte into the first chamber and conducting a second electrolyte as anolyte into the second chamber; and charging or discharging the redox flow battery. The first electrolyte comprises a first reduction-oxidation pair and the second electrolyte comprises a second reduction-oxidation pair. At least one of the first electrolyte and the second electrolyte comprises a pH-stabilizing buffer for chemically stabilizing the reduction-oxidation pair.

A polar plate is fabricated. The polar plate is flexible and made of a plastic graphite composite. No matter a supporting member is used for calendering or not, a thin polar plate with controllable thickness is fabricated. The polar plate is excellent in blocking the through-transmission of vanadium ions and the limit of blending ratio of conductive carbon is broken through. The longitudinal through-transmission volume resistivity (proportional resistance to thickness) is greatly improved by adjusting the blending ratio of conductive carbon for meeting the demand of conductivity. In the mean time, the present invention strengthens the rigidity required for the thin polar plate while providing large-area polar plate fabrication for industrial use and convenience and provides a cooling and pressing method for patterning a composite polar plate. An integrated mold is thus obtained to replace the conventional polar plate which needs to be processed and prepared with runner.

A flow battery includes a positive electrode, a positive electrode electrolyte, a negative electrode, a negative electrode electrolyte, and a polymer electrolyte membrane interposed between the positive electrode and the negative electrode. The positive electrode electrolyte includes water and a first redox couple. The first redox couple includes a first organic compound which includes a first moiety in conjugation with a second moiety. The first organic compound is reduced during discharge while during charging the reduction product of the first organic compound is oxidized to the first organic compound. The negative electrode electrolyte includes water and a second redox couple. The second couple includes a second organic compound including a first moiety in conjugation with a second moiety. The reduction product of the second organic compound is oxidized to the second organic compound during discharge.

Systems and methods are provided for electrolyte and current circulation in a redox flow battery system. In one example, the redox flow battery system may include a plurality of redox flow battery cells electrically coupled in series. In this way, a potential difference across the plurality of redox flow battery cells may be ramped up, such that relatively high voltage external loads may be powered by the redox flow battery system. In some examples, each of the plurality of redox flow battery cells may be fluidically isolated from one another. As such, in one example, the redox flow battery system may further include a plurality of electrolyte storage tanks respectively fluidically coupled to the plurality of redox flow battery cells. Such fluidic isolation of each of the plurality of redox flow battery cells may eliminate stack-to-stack shunting in the redox flow battery system, as well as improve a modularity thereof.

Systems and methods are provided for electrolyte distribution, rebalancing, and storage in a redox flow battery system. In one example, the redox flow battery system may include a plurality of redox flow battery cells and a plurality of storage tanks respectively fluidically coupled thereto, wherein a gauge pressure in each of the plurality of storage tanks may be maintained below a relatively low pressure (for example, below 2 psi). In some examples, the redox flow battery system may further include a plurality of rebalancing cells respectively fluidically coupled to the plurality of storage tanks, each of the plurality of rebalancing cells including a stack of internally shorted electrode assemblies. In this way, the redox flow battery system may be operated at less than the relatively low pressure, such that multiple space effective (for example, prismatic and relatively small) storage tanks may be included.