Bipolar electrodes comprising a carbon felt loaded with a polymer material and a nanocarbon material are described herein. The bipolar electrodes are useful in electrochemical cells. In particular, the loaded carbon felt can be used in bipolar electrodes of zinc-halide electrolyte batteries. Processes for manufacturing the loaded carbon felt are also described, involving contacting (e.g., dipping) a carbon felt in a mixture of solvent, polymer material and nanocarbon material.

A redox flow battery cell includes: an electrode to which an electrolyte solution is supplied; and a bipolar plate with which the electrode is arranged, wherein the bipolar plate has at least one groove portion through which the electrolyte solution flows, on a face on the electrode side, the electrode is made of a carbon fiber aggregate containing carbon fibers, and has a buried portion that is pressed toward the bipolar plate side and buried into the groove portion, and an amount of burial of the buried portion is not less than 0.2 mm and not more than 1.4 mm.

Systems and methods are provided for a redox flow battery. In one example, a method for the redox flow battery includes operating the redox flow battery in a short-term idle mode by discharging a current density as a pulse of a duration shorter than a duration of the short term idle mode. By discharging the current density, a plating surface at a negative electrode of the redox flow battery system may be maintained.

A redox flow battery including an electrode assembly, the electrode assembly including a carbon block having pores and a flow frame having a first and a second surface, wherein the carbon block is accommodated on one or both of the first and second surfaces.

A battery cell that has a supply edge to which an electrolyte solution is supplied and a discharge edge from which the electrolyte solution is discharged has an introduction port that connects with the supply edge and a discharge port that connects with the discharge edge, and includes a plurality of meandering flow paths each of which is serially formed from the introduction port to the discharge port, the plurality of meandering flow paths being arranged in parallel in a widthwise direction. Each of the meandering flow paths has an introduction-side section extending from the introduction port toward a discharge edge side, a turn-back section that is turned back from an end portion on the discharge edge side of the introduction-side section toward a supply edge side, and a discharge-side section reaching the discharge port from an end portion on the supply edge side of the turn-back section.

The invention relates to a distributor structure (12, 20), particularly a bipolar plate for a stack structure (10) of a fuel cell or of an electrolyser. The distributor structure (12, 20) comprises a channel structure (48) that interacts with at least one polymer membrane (16). The distributor structure (12, 20) is designed as a plastic part (40) that has electrically conductive properties.

The disclosure relates to a fuel cell, a bipolar plate and a bipolar plate assembly for a fuel cell. The bipolar plate comprises: at least one distributing region; at least one first through hole which communicates with the distributing region via a circumferential opening on a sidewall as an inlet of a first reactant; and at least one second through hole which communicates with the distributing region via a circumferential opening on a sidewall as an outlet of a first reactant. Each of the at least one first through hole and the at least one second through hole has a cross section of approximately trapezoid with an arc edge or an oblique edge, and the circumferential opening is formed on a curved sidewall or on an oblique sidewall. The fuel cell has improved structural design of the bipolar plate to improve flow uniformity and hydrothermal management of the fuel cell.

A cell stack is in which a plurality of battery cells are stacked, including an electrode of a porous body, and a bipolar plate facing the electrode, in which the bipolar plate includes an introduction portion of an electrolyte, a discharge portion of the electrolyte, and a plurality of first grooves extending from a side at which the introduction portion is disposed toward a side at which the discharge portion is disposed, each of the plurality of first grooves allows the electrolyte in each of the plurality of first grooves flow toward the discharge portion, R.sub.2/R.sub.1 is 7×10.sup.−11 or more and 2×10.sup.−4 or less, R.sub.1 is a permeation resistance indicating a difficulty of a flow of the electrolyte in the electrode, and R.sub.2 is a permeation resistance indicating the difficulty of the flow of the electrolyte in each of the plurality of first grooves.

Systems and methods are provided for a redox flow battery. In one example, a method for the redox flow battery includes operating the redox flow battery in a short-term idle mode by discharging the redox flow battery at a constant current density over a duration of the short-term idle mode. By discharging the current density, a plated surface at a negative electrode of the redox flow battery may be maintained.

A gas diffusion layer for an electrolyser or for a fuel cell comprises a first nonwoven layer of metal fibers provided for contacting a proton exchange membrane, a second nonwoven layer of metal fibers, and a third porous metal layer. The first nonwoven layer of metal fibers comprises metal fibers of a first equivalent diameter. The second nonwoven layer of metal fibers comprises metal fibers of a second equivalent diameter. The second equivalent diameter is larger than the first equivalent diameter. The third porous metal layer comprises open pores. The open pores of the third porous metal layer are larger than the open pores of the second nonwoven layer of metal fibers. The second nonwoven layer is provided in between and contacting the first nonwoven layer and the third porous metal layer. The second nonwoven layer is metallurgically bonded to the first nonwoven layer and to the third porous metal layer. The thickness of the third porous metal layer is at least two times—and preferably at least three times—the thickness of the first nonwoven layer.