Cathode electrode structures for sodium sulphur cells and their manufacture.

摘要

A cathode structure for a sodium sulphur cell is formed of fibre material which at least predominantly is of carbon fibre and in which the fibre orientation is such that the fibres have a component of direction extending from the electrolyte to the cathode current collector. A number of methods of forming such a structure are described in which use is made of fibre sheet material (10, 15, 25) in which the fibres lie in planes parallel to the plane of the sheet and in which segments of the material formed as corrugations in the sheet or as strips cut from the sheet are reoriented, either before or after impregnation with sulphur, to provide an assembly with fibres extending in the required direction, this assembly of segments being shaped by compression in a mould whilst the sulphur is molten, to form elements adapted to fit in an annular cathodic region of a sodium sulphur cell.