Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing fluid communication with the cathode, the catholyte solution comprising a polyoxometallate redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode, the catholyte solution comprising at least about 0.075M of the said polyoxometallate, and a vanadium (IV) compound.

Abstract: The invention concerns the use as a redox a catalyst and/or mediator in a fuel cell catholyte solution of the compound of Formula (I) wherein: X is selected from hydrogen and from various functional groups; R1-8 are independently selected from hydrogen and various functional groups; wherein R1 and X and/or R5 and X may together form an optionally substituted ring structure; wherein R1 and R2 and/or R2 and R3 and/or R3 and R4 and/or R4 and R8 and/or R8 and R7 and/or R7 and R6 and/or R6 and R5 may together form an optionally substituted ring structure; wherein (L) indicates the optional presence of a linking bond or group between the two neighboring aromatic rings of the structure, and when present may form an optionally substituted ring structure with one or both of R4 and R8; and wherein at least one substituent group of the structure is a charge-modifying substituent.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing in fluid communication with the cathode, the catholyte solution comprising a redox mediator which is at least partially reduced at the cathode in operation of the cell, and at least partially regenerated by, optionally indirect, reaction with the oxidant after such reduction at the cathode, and a transition metal complex of a multidentate N-donor ligand as a redox catalyst catalyzing the regeneration of the mediator.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing fluid communication with the cathode, the catholyte solution comprising a polyoxometallate redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode, the catholyte solution comprising at least one counterion for the polyoxometallate redox couple wherein the at least one counterion comprises one or more divalent ions.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing fluid communication with the cathode, the catholyte solution comprising a polyoxometallate redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode, the catholyte solution comprising at least about 0.075M of the said polyoxometallate.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing in fluid communication with the cathode, the catholyte solution comprising a redox mediator which is at least partially reduced at the cathode in operation of the cell, and at least partially regenerated by, optionally indirect, reaction with the oxidant after such reduction at the cathode, and a transition metal complex of a multidentate N-donor ligand as a redox catalyst catalyzing the regeneration of the mediator the multi-dentate N-donor ligand comprising at least one heterocyclic substituent selected from pyrrole, imidazole, 1,2,3-triazole, 1,2,4-triazole, pyrazole, pyridazine, pyrimidine, pyrazine, indole, tetrazole, quinoline, i

Abstract: There is provided a method of regenerating a catholyte solution in a redox fuel cell, comprising the steps of: providing a redox fuel cell comprising a catholyte solution; providing droplet formation means for catholyte solution atomisation; atomising, by way of the droplet formation means or other means, the catholyte solution, thereby generating a mist of fine droplets; feeding the mist of fine droplets into an oxidant stream; regulating the oxidant stream flow so that time of flight of the droplets is sufficient to accomplish required mass transfer; reaching sufficient time of flight; and providing separation means for separating the mist of fine droplets from the oxidant stream. A regeneration zone, a fuel cell, and use of the regeneration zone are also provided.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing in fluid communication with the cathode, the catholyte solution comprising a redox mediator which is at least partially reduced at the cathode in operation of the cell, and at least partially regenerated by, optionally indirect, reaction with the oxidant after such reduction at the cathode, and a transition metal complex of a multidentate macrocyclic N-donor ligand as a redox catalyst catalysing the regeneration of the mediator.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing fluid communication with the cathode, the catholyte solution comprising a polyoxometallate redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode, the catholyte solution comprising at least about 0.075M of the said polyoxometallate, and a vanadium (IV) compound.

Abstract: The present invention concerns a fuel cell comprising a cathode in a cathode region of the cell and an anode in an anode region of the cell, the cathode being separated from the anode by an ion selective polymer electrolyte membrane, the cathode region of the cell being supplied in use thereof with an oxidant and a liquid low molecular weight fuel wherein at least some of the liquid low molecular weight fuel in use crosses the polymer electrolyte membrane to supply the anode region of the cell with liquid low molecular weight fuel, the cell being provided with means for generating an electrical circuit between the cathode and the anode.

Abstract: A redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a catholyte solution comprising a modified ferrocene species being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode.

Abstract: The invention provides a fuel cell comprising an anode in an anode region of the cell and a cathode in a cathode region of the cell, the anode being separated from the cathode by an ion selective polymer electrolyte membrane, the anode region of the cell being supplied in use thereof with an alcoholic fuel, the cathode region of the cell being supplied in use thereof with an oxidant, the cell being provided with means for generating an electrical circuit between the anode and the cathode and with a non-volatile redox couple in solution in flowing fluid communication with the cathode in the cathode region of the cell, the redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially regenerated by reaction with the oxidant after such reduction at the cathode.

Abstract: The invention concerns the use as a redox a catalyst and/or mediator in a fuel cell catholyte solution of the compound of Formula (I) wherein: X is selected from hydrogen and from various functional groups; R1-8 are independently selected from hydrogen and various functional groups; wherein R1 and X and/or R5 and X may together form an optionally substituted ring structure; wherein R1 and R2 and/or R2 and R3 and/or R3 and R4 and/or R4 and R8 and/or R8 and R7 and/or R7 and R6 and/or R6 and R5 may together form an optionally substituted ring structure; wherein (L) indicates the optional presence of a linking bond or group between the two neighbouring aromatic rings of the structure, and when present may form an optionally substituted ring structure with one or both of R4 and R8; and wherein at least one substituent group of the structure is a charge-modifying substituent.

Abstract: A redox fuel cell comprising a catholyte solution comprising at least one non-volatile catholyte component, the catholyte solution comprising a redox mediator couple; and a regeneration zone separate from the membrane electrode assemblies of the fuel cell, the means for supplying an oxidant to the fuel cell being adapted to supply the oxidant to the regeneration zone, the volume of catholyte solution in the regeneration zone being from about 25% to about 90% of the total combined volume of catholyte solution in the regeneration zone and the cathode chambers of the fuel cell.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing in fluid communication with the cathode, the catholyte solution comprising a redox mediator which is at least partially reduced at the cathode in operation of the cell, and at least partially regenerated by, optionally indirect, reaction with the oxidant after such reduction at the cathode, and a transition metal complex of a multidentate N-donor ligand as a redox catalyst catalysing the regeneration of the mediator the multi-dentate N-donor ligand comprising at least one heterocyclic substituent selected from pyrrole, imidazole, 1,2,3-triazole, 1,2,4-triazole, pyrazole, pyridazine, pyrimidine, pyrazine, indole, tetrazole, quinoline, i

Abstract: The present invention concerns a fuel cell comprising a cathode in a cathode region of the cell and an anode in an anode region of the cell, the cathode being separated from the anode by an ion selective polymer electrolyte membrane, the cathode region of the cell being supplied in use thereof with an oxidant and a liquid low molecular weight fuel wherein at least some of the liquid low molecular weight fuel in use crosses the polymer electrolyte membrane to supply the anode region of the cell with liquid low molecular weight fuel, the cell being provided with means for generating an electrical circuit between the cathode and the anode.

Abstract: A redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a catholyte solution comprising a modified ferrocene species comprising at least one bridging unit between the cyclopentadienyl rings, the modified ferrocene species being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing in fluid communication with the cathode, the catholyte solution comprising a redox mediator which is at least partially reduced at the cathode in operation of the cell, and at least partially regenerated by, optionally indirect, reaction with the oxidant after such reduction at the cathode, and a transition metal complex of a multidentate macrocyclic N-donor ligand as a redox catalyst catalysing the regeneration of the mediator.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing fluid communication with the cathode, the catholyte solution comprising a polyoxometallate redox couple being at least partially reduced at the cathode in operation of the cell, and at least partially re-generated by reaction with the oxidant after such reduction at the cathode, the catholyte solution comprising at least one counterion for the polyoxometallate redox couple wherein the at least one counterion comprises one or more divalent ions.

Abstract: This invention provides a redox fuel cell comprising an anode and a cathode separated by an ion selective polymer electrolyte membrane; means for supplying a fuel to the anode region of the cell; means for supplying an oxidant to the cathode region of the cell; means for providing an electrical circuit between the anode and the cathode; a non-volatile catholyte solution flowing in fluid communication with the cathode, the catholyte solution comprising a redox mediator which is at least partially reduced at the cathode in operation of the cell, and at least partially regenerated by, optionally indirect, reaction with the oxidant after such reduction at the cathode, and a transition metal complex of a multidentate N-donor ligand as a redox catalyst catalysing the regeneration of the mediator.