(JP9507334-W)      A rechargeable photoelectrochemical cell comprises a photoanode of at least one metallic oxide semiconductor on a conductive substrate, a counterelectrode and an electrolyte between these electrodes. At least one of the electrodes is transparent or translucent. The electrolyte comprises a redox system composed of a mixt. of at least one electrochemically active salt and at least one mol. capable of forming a redox system with the anion or cation of the salt. The system is in the liq. state at ambient temp. and/or in soln. in at least one electrochemically inactive salt having a m.pt. less than ambient temp.    Also claimed is the electrolyte compsn. for such a cell.    ADVANTAGE -   The electrolyte has a very low vapour pressure hence there is a low rate of evapn. and no risk of loss of performance due to precipitation of crystalline salt(s). The amt. of solvent used is much lower than in previous compsns. giving improved stability.    (US5728487-A)      A rechargeable photoelectrochemical cell comprises a photoanode of at least one metallic oxide semiconductor on a conductive substrate, a counterelectrode and an electrolyte between these electrodes. At least one of the electrodes is transparent or translucent. The electrolyte comprises a redox system composed of a mixt. of at least one electrochemically active salt and at least one mol. capable of forming a redox system with the anion or cation of the salt. The system is in the liq. state at ambient temp. and/or in soln. in at least one electrochemically inactive salt having a m.pt. less than ambient temp.    Also claimed is the electrolyte compsn. for such a cell.    ADVANTAGE -   The electrolyte has a very low vapour pressure hence there is a low rate of evapn. and no risk of loss of performance due to precipitation of crystalline salt(s). The amt. of solvent used is much lower than in previous compsns. giving improved stability.    (EP737358-B1)      A rechargeable photoelectrochemical cell comprises a photoanode of at least one metallic oxide semiconductor on a conductive substrate, a counterelectrode and an electrolyte between these electrodes. At least one of the electrodes is transparent or translucent. The electrolyte comprises a redox system composed of a mixt. of at least one electrochemically active salt and at least one mol. capable of forming a redox system with the anion or cation of the salt. The system is in the liq. state at ambient temp. and/or in soln. in at least one electrochemically inactive salt having a m.pt. less than ambient temp.    Also claimed is the electrolyte compsn. for such a cell.    ADVANTAGE -   The electrolyte has a very low vapour pressure hence there is a low rate of evapn. and no risk of loss of performance due to precipitation of crystalline salt(s). The amt. of solvent used is much lower than in previous compsns. giving improved stability.