Abstract: In one embodiment of the present disclosure, a composition for producing a vanadium electrolyte includes a vanadium compound and an ion solution containing vanadium ions and hydrogen ions. In another embodiment, a method for producing a vanadium electrolyte includes obtaining a vanadium compound, and mixing the vanadium compound with an ion solution containing vanadium ions and hydrogen ions.

Abstract: In accordance with embodiments of the present disclosure, a redox flow battery (RFB) may include a shell, an electrolyte storage tank assembly disposed in the shell, wherein at least a portion of the electrolyte storage tank assembly is supported by the shell, an electrochemical cell, and an electrolyte circulation system configured for fluid communication between the electrolyte storage tank assembly and the electrochemical cell. In some embodiments, at least a portion of the electrolyte storage tank assembly defines a tank assembly heat transfer system between an outer surface of the electrolyte storage tank assembly and an inner surface of the shell. In other embodiments, a pump assembly in the electrolyte circulation system is moveable between a first position and a second position. In other embodiments, a gas management system includes a first gas exchange device in fluid communication with the catholyte headspace and the anolyte.

Abstract: A method of operating a redox flow battery string including at least first and second redox flow batteries and an outside power source includes: providing a least first and second redox flow batteries in a string electrically connected in a string, and each redox flow battery having a state-or-charge (SOC); obtaining an SOC value for each redox flow battery in the string; identifying a target SOC value in the string; and adjusting the SOC value for at least one of the first and second redox flow batteries to correspond to the target SOC value.

Abstract: A method of operating a redox flow battery string includes providing a plurality of redox flow batteries, each redox flow battery in electrical communication with at least one other redox flow battery, and each redox flow battery comprising an anolyte storage tank including a quantity of anolyte, a catholyte storage tank including a quantity of catholyte, and an electrochemical cell in fluid communication with the anolyte and catholyte storage tanks; obtaining an open circuit voltage value for each redox flow battery in the string; identifying a predetermined open circuit voltage value in the string; and adjusting the open circuit voltage value for each redox flow battery to correspond to the predetermined open circuit voltage value. A redox flow battery string system includes a plurality of redox flow batteries each redox flow battery in electrical communication with at least one other redox flow battery having an open circuit voltage value.

Abstract: In one embodiment, a redox flow battery includes an electrochemical cell in fluid communication with anolyte and catholyte working electrolytes, and a primary OCV cell to measure the potential difference between the positive and negative working electrolyte, and a reference OCV cell to measure the potential difference between the reference cell working electrolyte, which is one of the anolyte and catholyte working electrolytes, and a reference electrolyte, wherein the reference electrolyte has a known potential. In another embodiment, a method of operating a redox flow battery includes calculating the potential values of the anolyte and catholyte working electrolytes based on the known potential values of the reference electrolyte and the first and second potential difference values obtained from the primary OCV cell and the reference OCV cell.

Abstract: A method of operating a redox flow battery string including at least first and second redox flow batteries and an outside power source includes: providing a least first and second redox flow batteries in a string electrically connected in a string, and each redox flow battery having a state-or-charge (SOC) and an electrical load, wherein the electrical load for at least one of the first and second redox flow batteries in the string is powered by the outside power source; obtaining an SOC value for each redox flow battery in the string; identifying a target SOC value in the string; and adjusting the SOC value for at least one of the first and second redox flow batteries to correspond to the target SOC value by using a portion of stored energy in the at least one first or second redox flow battery to supply power to the electrical load.

Abstract: Systems and methods for shunt current and mechanical loss mitigation in electrochemical systems include a conduit providing at least a portion of an electrically conductive pathway between the first and second electrochemical cells, wherein the conduit includes at least one shunt current suppression device configured as a loop, and/or a connector assembly for maintaining first and second connecting portions in adjacent positioning.

Abstract: A method of operating a redox flow battery includes: providing a redox flow battery configurable to be in off and on states and to be in an islanded state , the redox flow battery including an electrochemical cell in fluid communication with anolyte and catholyte storage tanks, wherein a portion of the anolyte and a portion of the catholyte is contained in the electrochemical cell, and wherein the redox flow battery is at least partially charged; identifying the redox flow battery to be in an off and islanded state; maintaining stored energy in the electrolyte in the electrochemical cell when the redox flow battery is in the off and islanded state; and using the energy stored in the electrolyte in the electrochemical cell to start the redox flow battery and enter the on state.

Abstract: A battery management system is configured to, in an island mode, cause a frequency adjustment (e.g., by 3 Hz) to voltage in the power system based on a state of charge. The frequency adjustment signals assets (e.g., loads, generators, energy storage devices) electrically coupled to a battery system to reduce or increase power. If the state of charge is below a threshold value, the frequency adjustment may signal a load to be decreased, power generation of a generator to be increased, or power output of an energy storage device to be increased. If the state of charge is above a threshold value, the frequency adjustment may signal a load to be maintained or increased, power generation of a generator to be decreased, or power output of an energy storage device to be decreased. The frequency adjustment may be calculated automatically as a function of the state of charge.

Abstract: A method of operating a redox flow battery string including at least first and second redox flow batteries and an outside power source includes: providing a least first and second redox flow batteries in a string electrically connected in a string, and each redox flow battery having a state-or-charge (SOC) and an electrical load, wherein the electrical load for at least one of the first and second redox flow batteries in the string is powered by the outside power source; obtaining an SOC value for each redox flow battery in the string; identifying a target SOC value in the string; and adjusting the SOC value for at least one of the first and second redox flow batteries to correspond to the target SOC value by using a portion of stored energy in the at least one first or second redox flow battery to supply power to the electrical load.

Abstract: A method of operating a redox flow battery includes providing a redox flow battery including an anolyte storage tank configured for containing a quantity of anolyte and an anolyte headspace, a catholyte storage tank configured for containing a quantity of a catholyte and a catholyte headspace, and a gas management system comprising at least one open conduit interconnecting the anolyte headspace and the catholyte headspace for free gas exchange between the anolyte and catholyte headspaces, and a passive gas exchange device in gaseous fluid communication with the anolyte headspace, the passive gas exchange device configured to release gas from the anolyte headspace to an exterior battery environment when an interior battery pressure exceeds an exterior battery pressure by a predetermined amount, and operating the battery.

Abstract: A method of operating a redox flow battery includes providing a redox flow battery including an anolyte storage tank configured for containing a quantity of anolyte and an anolyte headspace, a catholyte storage tank configured for containing a quantity of a catholyte and a catholyte headspace, and a gas management system comprising at least one open conduit interconnecting the anolyte headspace and the catholyte headspace for free gas exchange between the anolyte and catholyte headspaces, and a passive gas exchange device in gaseous fluid communication with the anolyte headspace, the passive gas exchange device configured to release gas from the anolyte headspace to an exterior battery environment when an interior battery pressure exceeds an exterior battery pressure by a predetermined amount, and operating the battery.

Abstract: Methods of determining concentrations and/or amounts of redox-active elements at each valence state in an electrolyte solution of a redox flow battery are provided. Once determined, the concentrations and/or amounts of the redox-active elements at each valence state can be used to determine side-reactions, make chemical adjustments, periodically monitor battery capacity, adjust performance, or to otherwise determine a baseline concentration of the redox-active ions for any purpose.

Abstract: A redox flow battery includes an anolyte storage tank configured for containing a quantity of anolyte and an anolyte headspace; a catholyte storage tank configured for containing a quantity of a catholyte and a catholyte headspace; and a gas management system comprising at least one conduit interconnecting the anolyte headspace and the catholyte headspace, and a gas exchange device configured to contain or release an evolving gas from either or both of the anolyte and catholyte storage tanks to an exterior battery environment when an interior battery pressure exceeds an exterior battery pressure by a predetermined amount.

Abstract: In one embodiment of the present disclosure, an electrochemical cell includes a positive portion including a cathode and a catholyte half-cell and a negative portion including an anode and an anolyte half-cell, wherein at least one of the catholyte half-cell and the anolyte half-cell has a plurality of electrolyte flow areas; an ion transfer membrane separating the positive portion and the negative portion; and at least one positive current collector in contact with the cathode and at least one negative current collector in contact with the anode.

Abstract: A redox flow battery includes an anolyte storage tank configured for containing a quantity of anolyte and an anolyte headspace; a catholyte storage tank configured for containing a quantity of a catholyte and a catholyte headspace; and a gas management system comprising at least one conduit interconnecting the anolyte headspace and the catholyte headspace, and a gas exchange device configured to contain or release an evolving gas from either or both of the anolyte and catholyte storage tanks to an exterior battery environment when an interior battery pressure exceeds an exterior battery pressure by a predetermined amount.

Abstract: A redox flow battery (RFB) controllable by a battery management system and having an energy output has a volume of at least 2000 liters and an energy density of at least 10 w-h/liter. In one embodiment, the RFB maintains at an energy density of at least 10 w-h/liter for a minimum of 50 continuous full charge/discharge cycles or the equivalent number of operating hours without user input.

Abstract: A method of operating an all vanadium redox flow battery includes providing an all vanadium redox flow battery comprising an anolyte storage tank including a volume of anolyte and a catholyte storage tank including a volume of catholyte; an electrochemical cell in fluid communication with the anolyte and catholyte storage tanks; and a predetermined range for the ratio of vanadium concentration between the anolyte and the catholyte; and transferring an amount of catholyte from the catholyte storage tank to the anolyte storage tank, or an amount of anolyte from the anolyte storage tank to the catholyte storage tank, to restore the ratio of vanadium concentration to the predetermined range. An all vanadium redox flow battery system includes means for transferring anolyte and catholyte between the anolyte and catholyte storage tanks to maintain a predetermined range for the ratio of vanadium concentration between the anolyte and the catholyte.

Abstract: A method of operating a redox flow battery string includes providing a plurality of redox flow batteries, each redox flow battery in electrical communication with at least one other redox flow battery, and each redox flow battery comprising an anolyte storage tank including a quantity of anolyte, a catholyte storage tank including a quantity of catholyte, and an electrochemical cell in fluid communication with the anolyte and catholyte storage tanks; obtaining an open circuit voltage value for each redox flow battery in the string; identifying a predetermined open circuit voltage value in the string; and adjusting the open circuit voltage value for each redox flow battery to correspond to the predetermined open circuit voltage value. A redox flow battery string system includes a plurality of redox flow batteries each redox flow battery in electrical communication with at least one other redox flow battery having an open circuit voltage value.

Abstract: A redox flow battery includes a battery housed in a substantially closed housing having at least first and second internal containers, wherein the first and second containers are in fluid communication with each other, and wherein the first container is configured for containing a quantity of electrolyte and providing a gas headspace above the electrolyte; an electrolyte circulation system configured to circulate the electrolyte between the first and second containers; and -an anti-siphon device configured to prevent siphoning between the first and second containers.