Abstract: In a sodium-sulphur battery cell, an extended surface area current collector is sandwiched between portions of solid electrolyte, also of extended surface area, which provide between them a space for the liquid sulphur. The spacing between the current collector and each of the portions does not exceed the maximum distance that the sodium ions can diffuse in the liquid sulphur during a specified recharge time. A plurality of portions defining a plurality of spaces for the liquid sulphur may be provided, each space having an extended surface area current collector sandwiched between the portions defining the space.A plurality of these battery cells may be arranged so that they are separated one from another by a bipolar electrode to provide a series connection.