A redox flow battery. The redox flow battery has a plurality of cells stacked on each other and three or more conductive terminals. The redox flow battery is able to vary a charge voltage and a discharge voltage by switching control.

The invention relates to a bipolar plate (10) for a fuel cell stack. The bipolar plate (10) respectively has two profiled separator plates (12, 14) respectively having an active area (16) and two distribution areas (18, 20) for supplying and discharging reaction gases and coolant to or from the active area (16), wherein the separator plates (12, 14) are designed and arranged on top of each other such that the respective bipolar plate (10) has separate channels (28, 30, 32) for the reaction gases and the coolant, which channels connect ports (22, 24, 26) for reaction gases and coolant of both distribution areas (18, 20) to each other. In the mounted fuel cell stack, the channels (28, 30) for the reaction gases are respectively bordered by a surface of a separator plate (12, 14) and a surface of a gas diffusion layer (58).

It is provided that the bipolar plate (10) have an impermeable first dividing plate (38), which respectively divides the channels (28) for a reaction gas in an inlet area (40) of the active area (16) into two volume areas and extends in the flow direction (42) of the reaction gas, wherein only one volume area of the channel (28) is adjacent to the gas diffusion layer (58).

The subject matter of the invention is also a fuel cell stack with such bipolar plates (10), as well as a fuel cell system with a fuel cell stack according to the invention.

An exemplary fuel cell component includes a plate comprising an electrically conductive material. An electrical connector includes a first portion embedded in the plate. A second portion of the electrical connector extends from the plate. The second portion is configured to make an electrically conductive connection with another device.

An exemplary fuel cell component includes a plate comprising an electrically conductive material. An electrical connector includes a first portion embedded in the plate. A second portion of the electrical connector extends from the plate. The second portion is configured to make an electrically conductive connection with another device.

There is a need to improve the positioning accuracy in stacking gas separators. A guide section 58 provided in a fuel cell manufacturing apparatus 50 has first and second guide members 52 arranged to be parallel to each other and away from each other in a horizontal direction and extended in a stacking direction of the gas separators. The gas separator has first and second engagement elements 28 provided at corresponding positions to the first and the second guide members 52 to have a concave and/or convex shape formed along its outer periphery. A manufacturing method of a fuel cell includes a stacking step of stacking a plurality of members including gas separators by engaging the first engagement element with the first guide member and engaging the second engagement element with the second guide member. The gas separators stacked by the stacking step satisfy such a configuration that a first support location of the first engagement element and a second support location of the second engagement element are arranged at positions away from each other across a center of gravity of the gas separator and that the center of gravity is located in a lower area in a direction of gravity below a straight line of connecting the first support location with the second support location on a stacking surface of the gas separator.

There is a need to improve the positioning accuracy in stacking gas separators. A guide section 58 provided in a fuel cell manufacturing apparatus 50 has first and second guide members 52 arranged to be parallel to each other and away from each other in a horizontal direction and extended in a stacking direction of the gas separators. The gas separator has first and second engagement elements 28 provided at corresponding positions to the first and the second guide members 52 to have a concave and/or convex shape formed along its outer periphery. A manufacturing method of a fuel cell includes a stacking step of stacking a plurality of members including gas separators by engaging the first engagement element with the first guide member and engaging the second engagement element with the second guide member. The gas separators stacked by the stacking step satisfy such a configuration that a first support location of the first engagement element and a second support location of the second engagement element are arranged at positions away from each other across a center of gravity of the gas separator and that the center of gravity is located in a lower area in a direction of gravity below a straight line of connecting the first support location with the second support location on a stacking surface of the gas separator.

Bipolar electrode (100) for use in an electrolysis unit, said bipolar electrode (100) comprising a planar main body having a first side and a second side, each of said first side and said second side being provided with a corresponding pattern of protrusions (125), wherein each of said protrusions has a geometrical base within the plane of said planar main body and a substantially planar top side (129), the orthogonal projection of said top side onto said main body being contained in said geometrical base, and wherein the top sides (129) of the respective protrusions (129) of said first side and said second side lie in two planes parallel to said planar main body, the electrode being further characterized by specific shape and orientation requirements. Method for producing the bipolar electrode as above described, which includes an embossing step.

A device and method that allows bipolar plates to be welded in a rotating transport device in a vertical position at high speed, thereby fulfilling the high requirements for loading, fixing, welding and unloading the components to a high degree. Overall, a high level of productivity is achieved with the device and method.

An electrochemical element stack that includes a plurality of stacked electrochemical elements, each of the electrochemical elements including a plate-like support provided with an internal passage. The plate-like support includes: a gas-permeable portion through which gas passes between the internal passage located inside the plate-like support and the outside; an electrochemical reaction portion covering the gas-permeable portion; and a first penetrated portion forming a supply passage through which fuel gas flows from the outside of the plate-like support to the internal passage. The plate-like supports of two adjacent electrochemical elements are opposed, an outer face of the first electrochemical element on which the electrochemical reaction portion is arranged is electrically connected to an outer face of the second electrochemical element on which the electrochemical reaction portion is not arranged, and a flowing portion through which air flows along the two adjacent outer faces is formed between the two outer faces.

In a fuel cell stack (1), a connection region SR in which a protrusion (67) of a current collecting plate (9) and a second output terminal (15) are electrically connected is formed within a belt-like range, namely, a connectable range SKH, between a first tangential line L1 tangential to the circumference of one through hole (10c) and a second tangential line L2 tangential to the circumference of the other through hole (10d). Therefore, since the flow of electric current generated in the fuel cell stack (1) is unlikely to be obstructed by the through holes (10), electric current is easily supplied to the second output terminal (15) from a current collecting section (65) of the current collecting plate (9) through the protrusion (67). As a result, a voltage loss is small, thereby improving the performance of the fuel cell stack (1).