Abstract: The invention provides a method of making an analogue of .beta."-alumina, the analogue having a layered .beta."-alumina spinel-type structure in which ate least some of the Na ions in the layers of Na ions separated by layers of Al and O ions in said .beta."-alumina spinel-type structure are replaced by substitute metal cations. The substitute metal cations are mono-, d- and/or trivalent. The method comprises dispersing in a boehmite having a well developed and highly ordered crystal structure at least one oxide of the substitute metal cations or a precursor thereof to form a starting mixture, and heating the mixture to a conversion temperature at which it is converted to the analogue.

Abstract: A high temperature rechargeable electrochemical power storage cell comprises an anode compartment containing a molten alkali metal anode; a cathode compartment containing an alkali metal aluminium halide molten salt electrolyte as well as a cathode which comprises an electronically conductible electrolyte-permeable porous matrix which has dispersed therein an active cathode substance, with the matrix being impregnated with said molten electrolyte; a separator separating the anode compartment from the electrolyte; and a wick in the anode compartment to enhance contact of alkali metal with the separator in the anode compartment. The wick comprises a layer of alkali metal wettable particles on the separator surface, and a metallic anchoring component abutting the wettable particles and protruding into the anode compartment.

Abstract: The invention provides a high temperature electrochemical cell having an anode and a cathode separated by a separator. The cell has a housing divided by the separator into two cell compartments for the anode and cathode, each of which compartments contains liquid at the cell operating temperature, and has a gas space therein above the liquid, containing an inert gas. The cell compartments are in communication with each other, e.g. by passage, and are otherwise sealed. This communication is above the levels of the liquid in the compartments at all stages of charge of the cell.

Abstract: The invention provides an anode for an electrochemical cell. There is an anode holder containing a molten sodium anode. The holder is a ceramic envelope which is a sodium conductor and the holder has a current collector in contact with the sodium and projection through an opening in the envelope wall. The envelope interior contains a unitary porous solid matrix permeable by and impregnated by sodium. The matrix is bonded to at least part of the inner surface of the wall of the envelope. The invention provides also a holder for the anode which is empty of sodium; and provides an electrochemical cell employing the anode; and it provides a method of making said anode and holder.

Abstract: The invention provides a compressed envelope of solid electrolyte for holding an electrode in an electrochemical cell. The envelope comprises corrugated sheets joined along their edges. The sheets are aligned with each other so that their corrugations extend parallel along the length of the envelope and a space is defined between the sheets. The corrugations of the sheets nest in each other where the sheets are joined together at the ends of the envelope. The invention also provides a method of making the envelope and a cell having an electrode held in said envelope.

Abstract: The invention provides a method of making a flattened solid electrolyte, e.g. .beta.-alumina, envelope for use as an electrode holder in an electrochemical cell. A mouldable mixture of the .beta.-alumina with a binder is formed into sheet material and two panels of the sheet material are joined together along their peripheral edges to form the envelope. Spacing and reinforcing means is provided between the panels to space them apart and to reinforce the envelope. The edges of the panels are joined together using pressure, heat and/or solvent, after which are envelope is heated to cure the binder, volatilize the cured binder and sinter the solid electrolyte.

Abstract: A method of making an electrochemical cell comprises loading into the cathode compartment of a cell housing comprising an anode compartment separated from a cathode compartment by a separator which is a solid conductor of ions of alkali metal M or is a micromolecular sieve which contains alkali metal M sorbed therein; an alkali metal aluminium halide molten salt electrolyte having the formula MAlHal.sub.4 wherein M is the alkali metal of the anode and Hal is a halide; Cu as an active cathode substance; and an alkali metal halide MHal wherein M and Hal are respectively an alkali metal and a halide; thereby to make an electrochemical cell precursor.

Abstract: The invention provides a method of joining together a ceramic component and a metal component. According to the invention a surface of the ceramic component is metallized with a metallizing metal to form a metallized layer thereon. The metal component is then thermocompression bonded to the metallized layer, optionally after the metallized layer is plated with a continuous metal layer. For electrochemical cell applications, the ceramic component is typically alpha-alumina, the metal of the metallized layer is typically selected from tantalum, titanium, vanadium, tungsten and molybdenum, and the metal component typically comprises, in metallic or alloy form, at least one of iron, nickel, cobalt, chromium, manganese or copper.

Abstract: A method of making an electrochemical cell comprises loading into a cathode compartment of a cell housing comprising an anode compartment separated from a cathode compartment by a separator which is a solid conductor of ions of alkali metal M or is a micromolecular sieve which contains alkali metal M sorbed therein, an alkali metal aluminium halide molten salt electrolyte having the formula MAlHal.sub.4 wherein M is the alkali metal of the separator and Hal is a halide; an alkali metal halide MHal wherein M and Hal are respectively an alkali metal and a halide; a transition metal T selected from the group comprising Fe, Ni, Co, Cr, Mn and mixtures thereof, as an active cathode substance; and a current collector comprising at least one of copper, a copper-based substance, and a copper-coated substance, thereby to make an electrochemical cell precursor.

Abstract: An electrochemical cell 10 comprises, in its charged state, an anode 14 comprising, as an active anode substance, (i) a metal halide T(1).sup.m+ X.sub.m.sup.- where T(1) is a metal selected from the group consisting in the first series of transition elements, the second series of transition elements, tungsten, aluminium, silicon, tin and lead, m+ is the valency of the metal T(1), and X is a halogen. The cell also comprises a cathode 18 comprising, as an active cathode substance, a metal halide T(2).sup.n+ X.sub.n.sup.-, where T(2) is a metal selected from the group consisting in the first series of transition elements, the second series of transition elements, tungsten, aluminium, silicon, tin and lead, n+ is the valency of the metal T(2), and X is a halogen. The cell further comprises a liquid electrolyte 22, E, containing halogen ions X.sup.-, when the active anode and cathode substances are T(1).sup.m+ X.sub.m.sup.- and T(2).sup.n+ X.sub.n.sup.

Abstract: An electrochemical cell has a molten alkali metal anode separated by a separator which is a conductor of anode ions from an alkali metal aluminium halide molten electrolyte which couples the anode to a cathode having an active material comprising Fe, Ni, Co, Cr and/or Mn. The molten electrolyte is doped by a dopant M.sub.2 X, MY or M.sub.A Z in which M is the anode metal, X, Y and Z are respectively anions which are divalent, monovalent and polyvalent. The dopant acts to reduce the Lewis acidity of the molten electrolyte.

Abstract: The invention provides a high temperature rechargeable electrochemical power storage cell having an alkali metal anode molten at the cell operating temperatrure. A solid electrolyte separator conductive of ions of the anode separates the anode from a cathode having an electronically conductive electrolyte-permeable porous matrix impregnated with liquid electrolyte comprising cations of the anode metal and halide ions. Dispersed in the porous interior of the matrix is an electronically active cathode substance substantially insoluble in the liquid electrolyte. The separator is a sheet and the matrix of the cathode has the same peripheral outline as the sheet. The matrix is opposed to the sheet and is in register face-to-face therewith. The separator and sheet are located in a cell housing divided by the separator into an anode compartment containing the anode and a cathode compartment containing the cathode.

Abstract: The invention provides a cathode for an electrochemical cell, a cell incorporating the cathode, and a method of rendering the cathode resistant to a drop in capacity associated with cell cycling. The invention involves dispersing a transition metal, other than Ni, Fe, Cr, Co or Mn, in the active cathode substance, the cathode comprising an electronically conductive porous matrix impregnated with sodium aluminium halide molten salt electrolyte containing chloride ions. Said active cathode substance is an chlorinated nickel-containing substance dispersed in the matrix.

Abstract: The invention provides a method of making .beta."-alumina by heating aluminium oxide in the presence of Na.sub.2 O. A metal oxide dopant in the form of Li.sub.2 O, MgO, ZnO, CoO, NiO, FeO or mixtures thereof, or a precursor of the dopant, is dispersed in a cubic-close packed aluminium oxide or a precursor thereof to form a starting mixture which is calcined by heating to 250.degree.-1100.degree. C. in an oxygen-containing atmosphere. Na.sub.2 O is then dispersed in the calcined starting mixture to form a final mixture, and the final mixture is heated in an oxygen-containing atmosphere to above 1100.degree. C. to produce .beta."-alumina.

Abstract: The invention provides a rechargeable high temperature electrochemical storage cell having a molten alkali metal anode and a cathode separated from the anode by a ceramic solid electrolyte separator which is a conductor of ions of the anode. The separator has, in contact with its surface exposed to the alkali metal of the anode, a lining of material which is porous to and permeable by the molten alkali metal of the anode. The molten alkali metal of the anode, when in contact with the surface of the material of the lining, exhibits a contact angle of at least 90.degree. with respect to the surface of the lining material.

Abstract: The invention provides a method of making a composite beta-alumina artifact, such as a separator tube for an electrochemical cell, comprising two beta-alumina portions which are sealed together in a sealing zone, namely an inner portion and an outer portion which extends peripherally around the inner portion and embraces it in the sealing zone. The method comprises pressing the inner and outer portions from powders which, when sintered, shrink and form integral beta-alumina artifacts. The portions are then arranged so that the outer portion extends around the inner portion and embraces it in a sealing zone. The portions are then sintered to cause them to seal together hermetically in the sealing zone while converting each of the portions into a beta-alumina artifact.

Abstract: The invention provides a high temperature rechargeable electrochemical power storage cell which comprises an alkali metal anode which is molten at the operating temperature of the cell. The cell has a cathode and a separator which separates the anode from the cathode and which is a conductor of ions of the metal of the anode. The surface of the separator which is exposed to the anode is at least partly enclosed by and in contact with a layer of particulate material which acts as a wick for the molten alkali metal of the anode. The material of the particles of the layer is electronically conductive and chemically inert at the operating temperatures of the cell to the alkali metal of the anode and to the separator, and the particles thereof are coated by a surface coating.

Abstract: The invention provides a rechargeable electrochemical power storage cell. The cell has an anode compartment defined between a cell casing and a separator, the anode compartment containing active anode material which is liquid at the operating temperature of the cell. The separator defines a cathode compartment containing an electrolyte which is liquid at the operating temperature of the cell, and an active cathode material. The separator separates said compartments from each other and during discharge of the cell the active anode material passes from the anode compartment to the cathode compartment through the separator, to enter the cathode compartment in ionic form. The active anode material passes through the separator from the cathode compartment to the anode compartment during charging of the cell.

Abstract: A method of making an (alkali metal) (metal) halide compound and an alkali metal, the compound having the formula MDHal.sub.x+1 in which D is a metal; M is an alkali metal; Hal is a halide; and x is the valency of the metal D. The compound is made by exposing to one another a molten MDHal.sub.x+1 compound, a metal D and an alkali metal halide having the formula MHal. The MDHal.sub.x+1 compound is separated from a molten alkali metal M by means of a separator which is in contact with both the molten MAlHal.sub.4 and molten alkali metal. The separator can include a solid conductor of ions of the alkali metal or a micromolecular sieve having the alkali metal absorbed therein. A sufficient electrical potential is applied across the electrolytic cell D/MHal/MDHal.sub.x+1 .parallel.separator.parallel.alkali metal to cause the following reactions to take place: xMHal+D.fwdarw.XM+DHal.sub.x and MHal+DHal.sub.x .fwdarw.MDHal.sub.x+1.

Abstract: The invention provides a method of preparing a surface of a ceramic solid electrolyte conductor of alkali metal ions for wetting by said alkali metal in molten form. The method comprises doping the ceramic surface with an oxide of a transition metal. Transition metals such as Fe, Ni, Cu, Mn, Co, Cr or Mo have suitable oxides for doping beta-alumina for wetting by sodium.