Abstract: The present invention relates to an electrochemical sensor for determining the concentration of a group IA metal in a fluid such as molten metal. The sensor comprises a substantially pure quantity of the group 1A metal as a reference electrode (13) contained in a sensor housing (3), and a solid electrolyte constituting at least part of the sensor housing (3). The electrolyte is in electrical contact with the reference electrode (13) and the sensor is capable of operating at temperatures in excess of 973K. In a preferred arrangement, the sensor comprises a two part elongate conductor (15), a first part (17) of which extends from the reference electrode (13) into a refractory seal (11a), and a second part (19) of which extends from within the refractory seal (11a) externally of the sensor, the two parts (17, 19) being welded together.

Abstract: The present invention relates to an electrochemical sensor for determining the concentration of a group IA metal in a fluid such as molten metal. The sensor comprises a substantially pure quantity of the group 1A metal as a reference electrode (13) contained in a sensor housing (3), and a solid electrolyte constituting at least part of the sensor housing (3). The electrolyte is in electrical contact with the reference electrode (13) and the sensor is capable of operating at temperatures in excess of 973K. In a preferred arrangement, the sensor comprises a two part elongate conductor (15), a first part (17) of which extends from the reference electrode (13) into a refractory seal (11a), and a second part (19) of which extends from within the refractory seal (11a) externally of the sensor, the two parts (17, 19) being welded together.

Abstract: Superconducting ceramic material is prepared by mixing desired oxide powders, calcining them, forming a slurry of the calcined powders with a carrier liquid, depositing a layer of the ceramic from the slurry by electrophoretic deposition and then drying the layer. The layer should then be sintered to increase densification. Typical powders are oxides of Y, Ba and Cu in molar proportions 1:2:3 respectively.

Abstract: A battery module for a sodium sulphur battery containing a plurality of cells comprises a container housing the cells with an evacuated region between the cells and the walls of the container, this evacuated region containing a plurality of layers of metal foil between the cells and the wall. At least one tube extends through the module in contact with the cells for conveying a thermally-conductive fluid by means of which the cells can be heated or cooled.

Abstract: In a sodium sulphur cell, the cathode current collector in the sulphur/polysulphide cathodic reactant comprises an impermeable tube, e.g. a carbon or graphite tube which is inert to the cathodic reactant and contains a solid metal core, e.g. an aluminium core, and a deformable electronic conductor, e.g. graphite felt, as a conducting interface between the impermeable tube and the core. In a preferred construction, the current collector is axially located within a cylindrical electrolyte tube, the space between the electrolyte tube and impermeable tube containing the sulphur/polysulphides and a graphite felt. The outer surface of the impermeable tube in this case has grooves or recesses to form a sulphur reservoir.