TECHNOLOGY FOCUS - ELECTRONICS - Preferred Method: All or part of the fuel cell is maintained during operation at an elevated temperature and/or pressure. The speciation of the polyoxometallate occurs in situ. The elevated temperature is above 80 degrees C, preferably above 100 degrees C or not greater than 120 degrees C; is below the boiling point for the catholyte solution; is in the regeneration zone and/or in the cathode/anode region of the cell; or is in the regeneration zone. Both elevated temperature and pressure are used. The elevated pressure is above ambient pressure; is above 2 barG pressure; is in the regeneration zone and/or in the cathode/anode region of the cell; is in the regeneration zone. Preferred Redox Cell: The redox fuel cell contains 2-6 vanadium centers in the polyoxometallate. Preferred Components: The catholyte solution comprises at least one ancillary redox species. The ancillary redox species is selected from ligated transition metal complexes, and/or further polyoxometallate species. The catholyte solution is free from any ancillary redox species, other than the vanadium species.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The transition metal(s) in the transition metal complexes are selected from manganese in oxidation states II-V, iron I-IV, copper I-III, cobalt I-III, nickel I-III, chromium (II-VII), titanium II-IV, tungsten IV-VI, vanadium II-V and molybdenum II-VI.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polyoxometallate is of formula (X)a((Z1)b(M1)c(O)d) (I) (preferably (H)a1(P)z(Mo)y(V)x(O)b (II), especially H7PMo8V4O40 (III) or H12P3Mo18V7O85 (IV)).X=H, alkali metals, alkaline earth metals, ammonium or transition metal ions;Z1=B, P, S, As, Si, Ge, Ni, Rh, Sn, Al, Cu, I, Br, F, Fe, Co, Cr, Zn, H2, Te, Mn or Se;M1=vanadium and optionally at least one of Mo, W, Nb, Ta, Mn, Fe, Co, Cr, Ni, Zn Rh, Ru, TI, Al, Ga, In or other metals selected from 1st, 2nd and 3rd transition metal series and the lanthanide series;a=number of X necessary to charge balance the ((M1)c(O)d) anion;b=0-20;c=1-40;d=1-180;a1=number of H necessary to charge balance the ((P)z(Mo)y(V)x(O)b) anion;z=1-3;y=8-20;x=1-12;b=40-89.