One embodiment provides a method for predicting maintenance of a redox flow battery, the method including: receiving, from a plurality of sensors, data regarding characteristics of the redox flow battery; weighting, using a processor, each of the characteristics to form an estimated state parameter for the redox flow battery; and determining, using the processor, a maintenance action for the redox flow battery using the estimated state parameter. Other aspects are described and claimed.

One embodiment provides a method for predicting maintenance of a redox flow battery, the method including: receiving, from a plurality of sensors, data regarding characteristics of the redox flow battery; weighting, using a processor, each of the characteristics to form an estimated state parameter for the redox flow battery; and determining, using the processor, a maintenance action for the redox flow battery using the estimated state parameter. Other aspects are described and claimed.

A method of refurbishing a singulated fuel cell stack interconnect includes scanning a first pulsed laser beam on an air side of the interconnect to vaporize seal and corrosion barrier layer residue without vaporizing a metal oxide layer located on the air side of the interconnect below the corrosion barrier layer residue, and scanning a second pulsed laser beam which is different from the first pulsed laser beam on the exposed metal oxide layer on the air side of the interconnect to reflow the metal oxide layer without removing the metal oxide layer.

The process is described for recycling a heat-treated solid article including a fluorinated polymer having a fluorinated polymer backbone chain and a plurality of groups represented by formula —SO.sub.3Z, wherein Z is independently a hydrogen, an alkali-metal cation, or a quaternary ammonium cation. The heat-treated solid article was previously heated at a temperature of at least 100° C. The process includes heating the heat-treated solid article in the presence of water and base to form a fluorinated polymer salt solution, allowing the fluorinated polymer salt solution to cool, and converting the fluorinated polymer salt solution to fluorinated polymer solution wherein Z is hydrogen by cation exchange.

The process is described for recycling a heat-treated solid article including a fluorinated polymer having a fluorinated polymer backbone chain and a plurality of groups represented by formula —SO.sub.3Z, wherein Z is independently a hydrogen, an alkali-metal cation, or a quaternary ammonium cation. The heat-treated solid article was previously heated at a temperature of at least 100° C. The process includes heating the heat-treated solid article in the presence of water and base to form a fluorinated polymer salt solution, allowing the fluorinated polymer salt solution to cool, and converting the fluorinated polymer salt solution to fluorinated polymer solution wherein Z is hydrogen by cation exchange.

A method of refurbishing a singulated fuel cell stack interconnect includes scanning a first pulsed laser beam on an air side of the interconnect to vaporize seal and corrosion barrier layer residue without vaporizing a metal oxide layer located on the air side of the interconnect below the corrosion barrier layer residue, and scanning a second pulsed laser beam which is different from the first pulsed laser beam on the exposed metal oxide layer on the air side of the interconnect to reflow the metal oxide layer without removing the metal oxide layer.

A method of refurbishing a singulated fuel cell stack interconnect includes scanning a first pulsed laser beam on an air side of the interconnect to vaporize seal and corrosion barrier layer residue without vaporizing a metal oxide layer located on the air side of the interconnect below the corrosion barrier layer residue, and scanning a second pulsed laser beam which is different from the first pulsed laser beam on the exposed metal oxide layer on the air side of the interconnect to reflow the metal oxide layer without removing the metal oxide layer.

A method of monitoring and replacing fuel cells within a fuel cell stack assembly. The method includes measuring one or more operating conditions of a fuel cell within the fuel cell stack assembly. The method includes determining, using a processor, a state of health of the fuel cell based at least in part on the one or more operating conditions. The method includes detaching the fuel cell from an adjacent cell within the fuel cell stack assembly by removing a first electrically-conducing mating matrix associated with a first endplate of the fuel cell from a second electrically-conducing mating matrix associated with a second endplate of the adjacent cell. The method includes attaching a replacement fuel cell by mating a third electrically-conducing mating matrix associated with a third endplate of the replacement fuel cell with a fourth electrically-conducing mating matrix associated with a fourth endplate of the adjacent cell.

A unit cell for a fuel cell stack including an anode catalyst layer separated by a polymer electrolyte membrane from a cathode catalyst layer, a first cell end plate separated by a first gas diffusion layer from the anode catalyst layer, and a second cell end plate separated by a second gas diffusion layer from the cathode catalyst layer, wherein the first cell end plate, the second cell end plate, or both include a matrix of electrically-conducting protrusions thereof.

A method for recovering gold, silver, and/or platinum from components of a fuel cell stack of a fuel cell or electrolyzer includes treating the components with an aqueous electrolyte solution and with at least one gaseous oxidant in the fuel cell or the electrolyzer in an oxidation step. In a reduction step, the components are treated with a flow of an aqueous electrolyte solution and with at least one gaseous reductant in the fuel cell or the electrolyzer. A device by which the method can be carried out has a reservoir for the electrolyte solution, a line connected to an outlet opening of the reservoir, the line having a pump, an anode inlet connection connected to an anode inlet, and a cathode inlet connection connected to a cathode inlet. An oxidant-introducer introduces a gaseous oxidant into the line. A reductant-introducer introduces a gaseous reductant and/or inert gas into the line.