Abstract: A redox flow battery (RFB) system with a low-cost online turbidity sensor to detect the early stages of electrolyte precipitate formation is described. The inline turbidity sensor can be used in either absorption or scattering mode. The RFB system may optionally include an RGB color sensor to monitor the charge-discharge cycles by detecting color change in the electrolyte.

Abstract: Rebalancing methods and systems for redox flow battery systems are described. A reductant is selectively introduced from a reductant container into one or more of a rebalancing tank, the negative electrolyte tank, or the positive electrolyte tank to reduce Fe3+ ions to Fe2+ ions. The rebalancing system can be controlled by a controller in response to one or more measured properties of the iron flow battery.

Abstract: Stable and high performance positive and negative electrolytes compositions to be used in redox flow battery systems are described. The redox flow battery system, comprises: at least one rechargeable cell comprising a positive electrolyte, a negative electrolyte, and an ionically conductive membrane positioned between the positive electrolyte and the negative electrolyte, the positive electrolyte in contact with a positive electrode, and the negative electrolyte in contact with a negative electrode. The positive electrolyte consists essentially of water, a first amino acid, an inorganic acid, an iron precursor, a supporting electrolyte, and optionally a boric acid. The negative electrolyte consists essentially of water, the iron precursor, the supporting electrolyte, and a negative electrolyte additive. The iron precursor is FeCl2, FeCl3, FeSO4, Fe2(SO4)3, FeO, Fe, Fe2O3, or combinations thereof. The supporting electrolyte is LiCl, NaCl, Na2SO4, KCl, NH4Cl, or combinations thereof.

Abstract: Processes for limiting circulation of precipitates in a redox flow battery system are described. The processes include filtering the negative electrolyte, or the positive electrolyte, or both in one or more filters. The filter(s) can be located in the negative electrolyte loop, the positive electrolyte loop, or in both loops. Filtering can take place in normal operation; it can also take place during refresh cycles.

Abstract: Low cost membrane electrode assemblies (MEA) with improved coulombic efficiency (CE), reduced maintenance cost, and improved deliverable capacity have been developed for redox flow batteries and other electrochemical reaction applications. The MEA comprises: a microporous substrate membrane, first and second hydrophilic ionomeric polymer coating layers on surfaces of the microporous substrate membrane, and an electrode adhered to a second surface of the second hydrophilic ionomeric polymer coating layer. Methods of preparing the MEA and a redox flow battery system incorporating the MEA are also described.

Abstract: An ionically conductive asymmetric composite membrane for use in redox flow battery, fuel cell, electrolysis applications and the like is described. It comprises a microporous substrate membrane and an asymmetric hydrophilic ionomeric polymer coating layer on the surface of the microporous substrate layer. The coating layer is made of a hydrophilic ionomeric polymer. The asymmetric hydrophilic ionomeric polymer coating layer comprises a porous layer having a first surface and a second surface, the first surface of the porous layer on the surface of the microporous substrate layer and a nonporous layer on the second surface of the porous support layer. The microporous substrate membrane is made from a different polymer from the hydrophilic ionomeric polymer.

Abstract: Devices and methods for managing the state of health of an electrolyte in redox flow batteries (RFB) efficiently are described. A diffusion cell is added to the RFB which controls one or more properties of the electrolytes using the diffusion of protons through a proton exchange membrane. The diffusion cell can resemble an electrochemical cell in that there are two fluid chambers divided by a proton conducting membrane. Anolyte flows through one side of the device where it contacts the proton conducting membrane, and catholyte flows through the second side of the device where it contacts the other face of the proton conducting membrane. The concentration gradient of protons from high concentration in the catholyte to low concentration in the anolyte is the driving force for proton diffusion, rather than electromotive force, which greatly simplifies the design and operation.

Abstract: Devices and methods for managing the state of health of an electrolyte in redox flow batteries (RFB) efficiently are described. A diffusion cell is added to the RFB which controls one or more properties of the electrolytes using the diffusion of protons through a proton exchange membrane. The diffusion cell can resemble an electrochemical cell in that there are two fluid chambers divided by a proton conducting membrane. Anolyte flows through one side of the device where it contacts the proton conducting membrane, and catholyte flows through the second side of the device where it contacts the other face of the proton conducting membrane. The concentration gradient of protons from high concentration in the catholyte to low concentration in the anolyte is the driving force for proton diffusion, rather than electromotive force, which greatly simplifies the design and operation.

Abstract: Various current collectors for redox flow batteries are described. The current collectors include at least one metal plate encapsulated in a conductive polymer end plate, the metal plate to the back of a stack end plate with a conductive adhesive, and a flat metal plate having deformable tabs. Battery flow systems incorporating the current collectors are also described. Battery flow systems with easily replaceable current collectors are also described.

Abstract: Low cost membrane electrode assemblies (MEA) with improved coulombic efficiency (CE), reduced maintenance cost, and improved deliverable capacity have been developed for redox flow batteries and other electrochemical reaction applications. The MEA comprises: a microporous substrate membrane, first and second hydrophilic ionomeric polymer coating layers on surfaces of the microporous substrate membrane, and an electrode adhered to a second surface of the second hydrophilic ionomeric polymer coating layer. Methods of preparing the MEA and a redox flow battery system incorporating the MEA are also described.

Abstract: A flow battery system with a cathode cell including a first electrode, an anode cell includes a second electrode, and a membrane between the two cells. A first electrolyte tank includes a catholyte. A second electrolyte tank includes an anolyte. The system includes two rebalancing cells. A first rebalancing cell is in fluid communication between the cathode cell and the first electrolyte tank and is configured to reduce active species from the catholyte. The second rebalancing cell is in fluid communication with the first electrolyte tank and the second electrolyte tank such that the first electrolyte tank and the second electrolyte tank are in direct fluid communication. The second rebalancing cell is configured to reduce active species from the catholyte and the reduced catholyte may be combined directly with the anolyte. The second rebalancing cell may be a chemical reactor, a catalytic reactor, or an electrochemical reactor.

Abstract: An ionically conductive asymmetric composite membrane for use in redox flow battery, fuel cell, electrolysis applications and the like is described. It comprises a microporous substrate membrane and an asymmetric hydrophilic ionomeric polymer coating layer on the surface of the microporous substrate layer. The coating layer is made of a hydrophilic ionomeric polymer. The asymmetric hydrophilic ionomeric polymer coating layer comprises a porous layer having a first surface and a second surface, the first surface of the porous layer on the surface of the microporous substrate layer and a nonporous layer on the second surface of the porous support layer. The microporous substrate membrane is made from a different polymer from the hydrophilic ionomeric polymer.

Abstract: Stable and high performance positive and negative electrolytes compositions to be used in redox flow battery systems are described. The redox flow battery system, comprises: at least one rechargeable cell comprising a positive electrolyte, a negative electrolyte, and an ionically conductive membrane positioned between the positive electrolyte and the negative electrolyte, the positive electrolyte in contact with a positive electrode, and the negative electrolyte in contact with a negative electrode. The positive electrolyte consists essentially of water, a first amino acid, an inorganic acid, an iron precursor, a supporting electrolyte, and optionally a boric acid. The negative electrolyte consists essentially of water, the iron precursor, the supporting electrolyte, and a negative electrolyte additive. The iron precursor is FeCl2, FeCl3, FeSO4, Fe2(SO4)3, FeO, Fe, Fe2O3, or combinations thereof. The supporting electrolyte is LiCl, NaCl, Na2SO4, KCl, NH4Cl, or combinations thereof.

Abstract: A homogenously mixed metal manganese oxide. The mixed metal manganese oxide includes a homogenous mixture of manganese and at least two more metals. The additional metals may be cesium, nickel, copper, bismuth, cobalt, magnesium, iron, aluminum, scandium, vanadium, chromium, silver, gold, titanium, or, lead. A method of making the metal manganese oxide material includes mixing salts of manganese and the additional metals. The mixture may be activated and digested at an elevated temperature. Also, a battery having a cathode made from the homogenously mixed metal manganese oxide.

Abstract: A poorly crystalline mixed metal manganese oxide material. The mixed metal manganese oxide material may be used for making a cathode for a rechargeable battery. Generally, the mixed metal manganese oxide includes: manganese oxide; copper, silver, gold, or a combination thereof; a first additional cation selected from the group consisting of: bismuth, lead, and mixtures thereof; and a second additional cation selected from the group consisting of: lithium, sodium, potassium, cesium, rubidium, beryllium, magnesium, calcium, strontium, barium, NR4+, or a combination thereof, with R being, hydrogen, an alkyl group, an aryl group, or combinations thereof. The amorphous composition has an essentially amorphous x-ray powder diffraction pattern.

Abstract: A hydroprocessing catalyst has been developed. The catalyst is a crystalline transition metal tungstate material or metal sulfides derived therefrom, or both. The hydroprocessing using the crystalline transition metal tungstate material may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking. A data system comprising at least one processor; at least one memory storing computer-executable instructions; and at least one receiver configured to receive data of a conversion process comprising at least one reaction catalyzed by the catalyst or a metal sulfide decomposition product of the catalyst has been developed.

Abstract: A hydroprocessing catalyst or catalyst precursor has been developed. The catalyst is a transition metal molybdotungstate material or metal sulfides derived therefrom. The hydroprocessing using the transition metal molybdotungstate material may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

Abstract: A unique crystalline mixed transition metal tungstate material has been developed material may be sulfided to generate metal sulfides which are used as a catalyst in a conversion process such as hydroprocessing. The hydroprocessing may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

Abstract: A hydroprocessing catalyst or catalyst precursor has been developed. The catalyst is a poorly crystalline transition metal molybdotungstate material or a metal sulfide decomposition product thereof. The hydroprocessing using the crystalline ammonia transition metal molybdotungstate material may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

Abstract: A hydroprocessing catalyst has been developed. The catalyst is a crystalline transition metal tungstate material or metal sulfides derived therefrom, or both. The hydroprocessing using the crystalline transition metal tungstate material may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.