The present invention relates to an aqueous electrolyte composition comprising a sulfonic acid, optionally sulfuric acid, redox metal ions, and at least one inorganic additive (A) comprising at least one phosphorus atom whose degree of oxidation is less than or equal to +5. The present invention also relates to an electrochemical cell comprising said electrolyte composition and an oxidation-reduction battery (also called a redox battery) comprising such a cell.

The disclosed technology relates to redox flow batteries (“RFB”), and particularly to electrolytes useful in RFBs based on 2,5-dimercapto-1,3,4-thiadiazole (“DMTD”) and derivatives thereof.

A hybrid redox fuel cell system includes a hybrid redox fuel cell including an anode side through which a reductant is flowed and a cathode side through which liquid electrolyte is flowed, and a catalyst bed fluidly connected to the cathode side of the hybrid redox fuel cell, the catalyst bed including a substrate layer and a catalyst layer spiral wound into a jelly roll structure. Furthermore, the liquid electrolyte includes a metal ion at a higher oxidation state and the metal ion at a lower oxidation state, and power is generated at the hybrid redox fuel cell by way of reducing the metal ion from the higher oxidation state to the lower oxidation state at the cathode side while oxidizing the reductant at the anode side.

A redox flow battery cell includes a positive electrode and a negative electrode, and each of the positive electrode and the negative electrode is an assembly containing a plurality of carbon fibers, and a quantity per unit area of the negative electrode is larger than a quantity per unit area of the positive electrode.

Example implementations relate to novel battery designs based on the original disclosures of the Parent patent application Ser. No. 15/196,019. In a non-limiting embodiment, a first battery includes a ferroelectric glass electrolyte and a ferrocene Fe(C.sub.5H.sub.5).sub.2 molecule as a redox-mediator-relay material used for plating sodium on a current collector. Novel redox Fe(C.sub.5H.sub.5).sub.2 behavior is shown at a fixed (or a finite) voltage under discharge conditions. The disposed ferroelectric electrolyte material is predisposed to align itself in the direction of the electric field inside the battery, increasing the capacity of the battery. This description is not intended to be a complete description of, or to limit the scope of, the invention.

An organic positive electrode active material for aqueous redox flow batteries, and more particularly, to technology of applying an organic positive electrode active material to make up for the drawbacks of conventional aqueous redox flow batteries. An aqueous redox flow battery to which a particular positive electrode active material is applied has no problems regarding metal deposition, and can also be useful in realizing a high energy density because the positive electrode active material may be used at high concentration due to an increase in solubility in a solvent, attaining a high working voltage, and enhancing energy efficiency. Also, the aqueous redox flow battery has excellent economic feasibility because an expensive organic electrolyte is not used.

The present invention relates to the technical field of energy storage. Disclosed in the invention are a composite electrode for a flow cell, a flow cell, and a stack. The composite electrode comprises: a distribution layer, used to distribute an electrolyte; a reaction layer used to receive the electrolyte of the distribution layer and provide an electrochemical reaction site for the electrolyte; and a contact layer, used to reduce the contact resistance of the distribution layer so as to reduce an internal resistance of the flow cell. In the present invention, by means of providing a distribution layer, a reaction layer and a contact layer, an electrochemical reaction site and an electrolyte distribution site of a composite electrode can be effectively separated, the distribution layer being able to greatly reduce dead zones and channeling caused by uneven flow distribution, and the contact layer being able to greatly reduce the internal resistance of the flow cell. Meanwhile, the distribution layer and the reaction layer can be separately and specially designed, thus improving the output power and energy efficiency of a cell or a stack taking the present composite electrode as an anode and/or a cathode.

A system comprises an electrodialysis apparatus, which includes first and second reservoirs, wherein a salt concentration in the first reservoir reduces below a threshold concentration and salt concentration in the second reservoir increases during an operation mode. A first electrode comprises a first solution of a first redox-active electrolyte material, and a second electrode comprises a second solution of a second redox-active electrolyte material. In a first reversible redox reaction between the first electrode and first electrolyte material at least one ion is accepted from the first reservoir, and in a second reversible redox reaction between the second electrode and second electrolyte material at least one ion is driven into the second reservoir. A first type of membrane is disposed between the first and second reservoirs, and a second type of membrane, different from the first type, is disposed between the respective electrodes and reservoirs.

Provided in this patent disclosure are two types of novel fluoro-monomers that can be polymerized for the fabrication of ion-exchange fluoropolymers. In addition, new proton-conductive zirconium-perfluorophosphonic acid fluoropolymer membranes that can reduce metal crossovers in redox flow batteries are also provided.

Aspects of the subject disclosure may include, for example, a porous electrode that includes a porous layer, and a pattern of flow channels defined in the porous layer, wherein a first flow channel in the pattern of flow channels has a shape that at least partially approximates a cube-root profile. Additional embodiments are disclosed.