Abstract: An ocean alkalinity enhancement (OAE) system that reduces atmospheric CO2 and mitigates ocean acidification by electrochemically processing feedstock solution (e.g., seawater or brine) to generate an alkalinity product that is then supplied to the ocean. The OAE system includes a base-generating device and a control circuit disposed within a modular system housing deployed near a salt feedstock. The base-generating device (e.g., a bipolar electrodialysis (BPED) system) generates a base substance that is then used to generate the ocean alkalinity product. The control circuit controls the base-generating device such that the alkalinity product is supplied to the ocean only when (1) sufficient low/zero-carbon electricity is available, (2) it is safe to operate the base-generating device, and (3) supplying the alkalinity product will not endanger sea life.

Abstract: MRV for an ocean CDR system is achieved by varying the release/delivery of base substance into ocean seawater such that the base substance propagates as a series of release batch wavefronts along a dispersion path. A release frequency, which controls a timing of the release batch wavefronts, is selected to coincide with a non-natural frequency (e.g., a frequency exhibiting quiet/weak power spectra in a natural seawater chemistry variation power spectrum). Time-based seawater carbonate chemistry measurement data, which is collected by ocean-based sensors disposed in the base substance's dispersion path during base substance release, records both human-induced contributions caused by the release batch wavefronts and natural seawater chemistry variations.

Abstract: An ocean alkalinity enhancement (OAE) system that reduces atmospheric CO2 and mitigates ocean acidification by electrochemically processing feedstock solution (e.g., seawater or brine) to generate an alkalinity product that is then supplied to the ocean. The OAE system includes a base-generating device and a control circuit disposed within a modular system housing deployed near a salt feedstock. The base-generating device (e.g., a bipolar electrodialysis (BPED) system) generates a base substance that is then used to generate the ocean alkalinity product. The control circuit controls the base-generating device such that the alkalinity product is supplied to the ocean only when (1) sufficient low/zero-carbon electricity is available, (2) it is safe to operate the base-generating device, and (3) supplying the alkalinity product will not endanger sea life.

Abstract: An ocean alkalinity enhancement (OAE) system that reduces atmospheric CO2 and mitigates ocean acidification by electrochemically processing feedstock solution (e.g., seawater or brine) to generate an alkalinity product that is then supplied to the ocean. The OAE system includes a base-generating device and a control circuit disposed within a modular system housing deployed near a salt feedstock. The base-generating device (e.g., a bipolar electrodialysis (BPED) system) generates a base substance that is then tested and processed (e.g., mixed/diluted with processed feedstock solution, seawater or another saltwater solution and/or reacted with CO2) to generate the ocean alkalinity product. The control circuit controls the base-generating device such that the alkalinity product is supplied to the ocean only when supplying the alkalinity product will not endanger sea life.

Abstract: An ocean alkalinity enhancement (OAE) system that reduces atmospheric CO2 and mitigates ocean acidification by electrochemically processing feedstock solution (e.g., seawater or brine) to generate an alkalinity product that is then supplied to the ocean. The OAE system includes a base-generating device and a control circuit disposed within a modular system housing deployed near a salt feedstock. The base-generating device (e.g., a bipolar electrodialysis (BPED) system) generates a base substance that is then used to generate the ocean alkalinity product. The control circuit controls the base-generating device such that the alkalinity product is supplied to the ocean only when (1) sufficient low/zero-carbon electricity is available, (2) it is safe to operate the base-generating device, and (3) supplying the alkalinity product will not endanger sea life.

Abstract: Electrochemical cells, such as those present within flow batteries, can include at least one electrode with one face being more hydrophilic than is the other. Such electrodes can lessen the incidence of parasitic reactions by directing convective electrolyte circulation toward a separator in the electrochemical cell. Flow batteries containing the electrochemical cells can include: a first half-cell containing a first electrode with a first face and a second face that are directionally opposite one another, a second half-cell containing a second electrode with a first face and a second face that are directionally opposite one another, and a separator disposed between the first half-cell and the second half-cell. The first face of both the first and second electrodes is disposed adjacent to the separator. The first face of at least one of the first electrode and the second electrode is more hydrophilic than is the second face.

Abstract: The present invention is directed to novel membrane electrode assemblies, and devices and systems incorporating them. Representative membrane electrode assemblies comprise (a) a first, porous electrode; (b) a buffer layer optionally comprising an aqueous solution comprising a pH buffer; (c) a membrane; and (d) a second, porous electrode comprising a catalyst for the generation of oxygen (O2); wherein the membrane is interposed between the first electrode and the second electrode, and the buffer layer is interposed between the membrane and the first electrode.

Abstract: The present disclosure is directed to methods for levelizing circulation rates over multiple electrochemical cells of an electrochemical cell stack due to a pressure drop that occurs at an outlet of each electrochemical cell.

Abstract: The present invention is directed to novel membrane electrode assemblies, and devices and systems incorporating them. Representative membrane electrode assemblies comprise (a) a first, porous electrode; (b) a buffer layer optionally comprising an aqueous solution comprising a pH buffer; (c) a membrane; and (d) a second, porous electrode comprising a catalyst for the generation of oxygen (02); wherein the membrane is interposed between the first electrode and the second electrode, and the buffer layer is interposed between the membrane and the first electrode.

Abstract: Electrochemical cells, such as those present within flow batteries, can include at least one electrode with one face being more hydrophilic than is the other. Such electrodes can lessen the incidence of parasitic reactions by directing convective electrolyte circulation toward a separator in the electrochemical cell. Flow batteries containing the electrochemical cells can include: a first half-cell containing a first electrode with a first face and a second face that are directionally opposite one another, a second half-cell containing a second electrode with a first face and a second face that are directionally opposite one another, and a separator disposed between the first half-cell and the second half-cell. The first face of both the first and second electrodes is disposed adjacent to the separator. The first face of at least one of the first electrode and the second electrode is more hydrophilic than is the second face.

Abstract: The present disclosure is directed to methods for levelizing circulation rates over multiple electrochemical cells of an electrochemical cell stack due to a pressure drop that occurs at an outlet of each electrochemical cell.

Abstract: Electrolyte solution circulation rates in a flow battery can impact operating performance. Although adjusting the circulation rates can allow improved performance to be realized, it can be difficult to levelize circulation rates over multiple electrochemical cells of an electrochemical cell stack due to a non-uniform pressure drop that occurs at an outlet of each electrochemical cell. Accordingly, flow batteries capable of realizing improved operating performance can include: an electrochemical cell stack containing a plurality of electrochemical cells in electrical communication with one another; an inlet manifold containing an inflow channel fluidically connected to an inflow side of each of the electrochemical cells; an outlet manifold containing an outflow channel fluidically connected to an outflow side of each of the electrochemical cells; and an insert disposed in the outflow channel. The insert has a variable width along a length of the outflow channel.

Abstract: Electrochemical cells, such as those present within flow batteries, can include at least one electrode with one face being more hydrophilic than is the other. Such electrodes can lessen the incidence of parasitic reactions by directing convective electrolyte circulation toward a separator in the electrochemical cell. Flow batteries containing the electrochemical cells can include: a first half-cell containing a first electrode with a first face and a second face that are directionally opposite one another, a second half-cell containing a second electrode with a first face and a second face that are directionally opposite one another, and a separator disposed between the first half-cell and the second half-cell. The first face of both the first and second electrodes is disposed adjacent to the separator. The first face of at least one of the first electrode and the second electrode is more hydrophilic than is the second face.

Abstract: During operation of flow battery systems, the volume of one or more electrolyte solutions can change due to solvent loss processes. An electrochemical balancing cell can be used to combat volume variability. Methods for altering the volume of one or more electrolyte solutions can include: providing a first electrochemical balancing cell containing a membrane disposed between two half-cells, establishing fluid communication between a first aqueous electrolyte solution of a flow battery system and a first half-cell of the first electrochemical balancing cell, and applying a current to the first electrochemical balancing cell to change a concentration of one or more components in the first aqueous electrolyte solution. Applying the current causes water to migrate across the membrane, either to or from the first aqueous electrolyte solution, and a rate of water migration is a function of current.

Abstract: Electrochemical cells, such as those present within flow batteries, can have an electrode and a bipolar plate in at least one half-cell interfacially bonded together with an electrically conductive adhesive. Bonding the bipolar plate to the electrode can decrease contact resistance and sometimes lessen the incidence of parasitic reactions in the electrochemical cell. Flow batteries containing these features can include: a first half-cell containing a first electrode in interfacial contact with a first bipolar plate, a second half-cell containing a second electrode in interfacial contact with a second bipolar plate, and a separator disposed between the first half-cell and the second half-cell. An electrically conductive adhesive interfacially bonds at least one of the first electrode to the first bipolar plate and the second electrode to the second bipolar plate. Each electrode maintains fluid communication with its corresponding bipolar plate.

Abstract: Electrochemical cells, such as those present within flow batteries, can have at least one electrode with a density gradient in which the density increases outwardly from a separator. Such electrodes can decrease contact resistance and lessen the incidence of parasitic reactions in the electrochemical cell. Flow batteries containing the electrochemical cells can include: a first half-cell containing a first electrode, a second half-cell containing a second electrode, and a separator disposed between the first half-cell and the second half-cell. At least one of the first electrode and the second electrode has a density gradient such that a density of at least one of the first electrode and the second electrode increases outwardly from the separator.

Abstract: Electrolyte solution circulation rates in a flow battery can impact operating performance. Although adjusting the circulation rates can allow improved performance to be realized, it can be difficult to levelize circulation rates over multiple electrochemical cells of an electrochemical cell stack due to a non-uniform pressure drop that occurs at an outlet of each electrochemical cell. Accordingly, flow batteries capable of realizing improved operating performance can include: an electrochemical cell stack containing a plurality of electrochemical cells in electrical communication with one another; an inlet manifold containing an inflow channel fluidically connected to an inflow side of each of the electrochemical cells; an outlet manifold containing an outflow channel fluidically connected to an outflow side of each of the electrochemical cells; and an insert disposed in the outflow channel. The insert has a variable width along a length of the outflow channel.

Abstract: During operation of flow battery systems, the volume of one or more electrolyte solutions can change due to solvent loss processes. An electrochemical balancing cell can be used to combat volume variability. Methods for altering the volume of one or more electrolyte solutions can include: providing a first electrochemical balancing cell containing a membrane disposed between two half-cells, establishing fluid communication between a first aqueous electrolyte solution of a flow battery system and a first half-cell of the first electrochemical balancing cell, and applying a current to the first electrochemical balancing cell to change a concentration of one or more components in the first aqueous electrolyte solution. Applying the current causes water to migrate across the membrane, either to or from the first aqueous electrolyte solution, and a rate of water migration is a function of current.

Abstract: Electrochemical cells, such as those present within flow batteries, can include at least one electrode with one face being more hydrophilic than is the other. Such electrodes can lessen the incidence of parasitic reactions by directing convective electrolyte circulation toward a separator in the electrochemical cell. Flow batteries containing the electrochemical cells can include: a first half-cell containing a first electrode with a first face and a second face that are directionally opposite one another, a second half-cell containing a second electrode with a first face and a second face that are directionally opposite one another, and a separator disposed between the first half-cell and the second half-cell. The first face of both the first and second electrodes is disposed adjacent to the separator. The first face of at least one of the first electrode and the second electrode is more hydrophilic than is the second face.

Abstract: Electrochemical cells, such as those present within flow batteries, can have an electrode and a bipolar plate in at least one half-cell interfacially bonded together with an electrically conductive adhesive. Bonding the bipolar plate to the electrode can decrease contact resistance and sometimes lessen the incidence of parasitic reactions in the electrochemical cell. Flow batteries containing these features can include: a first half-cell containing a first electrode in interfacial contact with a first bipolar plate, a second half-cell containing a second electrode in interfacial contact with a second bipolar plate, and a separator disposed between the first half-cell and the second half-cell. An electrically conductive adhesive interfacially bonds at least one of the first electrode to the first bipolar plate and the second electrode to the second bipolar plate. Each electrode maintains fluid communication with its corresponding bipolar plate.