Abstract:
Described herein are systems and methods of hydrogen generation and electrolyte regeneration as independent operations in separate redox flow cells. The operations can be decoupled by using an energy-bearing redox pair that electrochemically bears energy facilitating flexible, efficient hydrogen generation. In one example, the hydrogen generation redox flow cell can include a liquid, energy-bearing electrolyte solution in which at least one species of an energy-bearing redox pair is dissolved, to decouple the hydrogen evolution reaction from the reaction at the opposite electrode (e.g., the oxygen evolution reaction of conventional direct water electrolysis). Each species of the energy-bearing redox pair is associated with a standard electrode potential within the water electrolysis window.
Abstract:
An energy storage device comprising: an anode; and a solute-containing electrolyte composition wherein the solute concentration in the electrolyte composition is sufficiently high to form a regenerative solid electrolyte interface layer on a surface of the anode only during charging of the energy storage device, wherein the regenerative layer comprises at least one solute or solvated solute from the electrolyte composition.
Abstract:
Magnesium energy storage devices that take advantage of magnesium-based anodes while maintaining practical energy densities can be useful for large-scale energy storage as well as other applications. One such device can include a negative electrode having magnesium and a positive electrode material that can flow in a batch or continuous manner. The flowable positive electrode material can result in an increased practical energy density because the fresh active material can be flowed to the positive electrode, and as a result can be theoretically infinite in size. The positive electrode can include a cathode suspension contacting a positive current collector and having particulates of a cathode magnesium intercalation compound, a cathode magnesium conversion compound, a redox active species, or combinations thereof.
Abstract:
In some aspects, the techniques described herein relate to a method of capturing carbon from seawater, the method including: flowing input seawater including bicarbonate and having a pH greater than 8 through a center compartment of an electrolytic cell, wherein the center compartment is disposed between an anode compartment and a cathode compartment of the electrolytic cell; acidifying the input seawater in the center compartment with a proton, to form acidified seawater; generating carbon dioxide in the center compartment including reaction of the proton with the bicarbonate from the input seawater; flowing acidified seawater out of the center compartment; contacting the acidified seawater with hydroxide or a hydroxide salt from the cathode compartment to generate basified seawater having a pH greater than 9; and flowing hydrogen generated in the cathode compartment to the anode compartment.
Abstract:
Catalysts comprising MoP and MoP2 are disclosed, wherein the catalyst is a composite. The catalyst may have a molar ratio of MoP:MoP2 within a range of 5:95 to 95:5. The catalyst may be used as a cathode active material for hydrogen generation from neutral pH solutions, such as wastewater or seawater. Methods of making the catalyst also are disclosed.
Abstract:
Aqueous anolytes for redox flow batteries are disclosed. The anolytes include a fluorenone-fluorenol derivative, an additive comprising an organic compound including one or more proton acceptor groups, an alkali metal hydroxide, and water. The additive functions as a homogeneous organocatalyst and may increase the current density of an aqueous redox flow battery including the anolyte.
Abstract:
Described herein are systems and methods of storing and delivering electrical using hydrogen at low-cost and for long-durations. The systems and methods use energy-bearing redox pairs that electrochemically bear energy through decoupled hydrogen and oxygen consumption and/or evolution reactions, which are typically associated with fuel cells. Each species of the energy-bearing redox pair is associated with a standard electrode potential within a water electrolysis voltage window for the electrolyte solution. Electrical energy delivery, hydrogen generation, electrolyte regeneration, or combinations thereof can be performed by logically or physically separated unit operations in a continuous manner, batch manner, or semi-batch manner facilitated by the energy-bearing redox pair.
Abstract:
Aqueous electrolytes comprising fluorenone/fluorenol derivatives are disclosed. The electrolyte may be an anolyte for an aqueous redox flow battery. In some embodiments, the compound, or salt thereof, has a structure according to any one of formulas I-III where Q1-Q4 independently are CH, C(R1) or N, wherein 0, 1, or 2 of Q1-Q4 are N; Q5-Q8 independently are CH, C(R2), or N, wherein 0, 1, or 2 of Q5-Q8 are N; Y is C═O or C(H)OH; R1 and R2 independently are an electron withdrawing group; n is an integer >1; and x and y independently are 0, 1, 2, 3, or 4, where at least one of x and y is not 0.
Abstract:
A solid-state lithium ion battery is disclosed. The battery includes an anode containing an anode active material. The battery also includes a cathode containing a cathode active material. The battery further includes a solid-state electrolyte material. The electrolyte material contains a salt or salt mixture with a melting point below approximately 300 degrees Celsius. The battery has an operating temperature of less than about 80 degrees Celsius.
Abstract:
Embodiments of a solid-state electrolyte comprising magnesium borohydride, polyethylene oxide, and optionally a Group IIA or transition metal oxide are disclosed. The solid-state electrolyte may be a thin film comprising a dispersion of magnesium borohydride and magnesium oxide nanoparticles in polyethylene oxide. Rechargeable magnesium batteries including the disclosed solid-state electrolyte may have a coulombic efficiency ≧95% and exhibit cycling stability for at least 50 cycles.