Abstract: In the manufacture of cells, e.g. of the system Li-Al/LiCl-KCl/FeS.sub.x, the finely divided raw materials for the electrodes and for an included ceramic separator are respectively mixed individually with the electrolyte salt, as well as with a synthetic plastic which is decomposable without residue under heat. The mixtures are rolled into plates, and the plates are heated above the decomposition temperature of the plastic after assembly. The plastic is preferably a polyhydrocarbon such as polyisobutylene and is preferably introduced by means of a solvent. It makes the powder mixtures plastifiable and suitable for rolling. This makes it possible to produce ceramic separators, which are fundamentally composed only of loose particle accumulations, in the form of plates of uniform structure and strength and to handle these in the same way as electrode plates during cell assembly.

Abstract: An improved secondary electrochemical cell is disclosed having a negative electrode of lithium aluminum, a positive electrode of iron sulfide, a molten electrolyte of lithium chloride and potassium chloride, and the combination that the fully charged theoretical capacity of the negative electrode is in the range of 0.5-1.0 that of the positive electrode. The cell thus is negative electrode limiting during discharge cycling. Preferably, the negative electrode contains therein, in the approximate range of 1-10 volume % of the electrode, an additive from the materials of graphitized carbon, aluminum-iron alloy, and/or magnesium oxide.

Abstract: High-temperature battery with at least one electrochemical storage cell of the alkali metal and chalcogen type and thermal insulation which surrounds the storage cell and is provided with feedthroughs for the electric conductors. Each of the electric conductors brought into the high-temperature battery consists of at least two subconductors which are connected to each other detachably and in an electrically conducting manner via at least one contact element. The contact element forming the contact point is arranged in the interior of the high-temperature battery.

Abstract: A current collector for the positive electrode of an electrochemical cell with a positive electrode including a sulfide. The cell also has a negative electrode and a molten salt electrolyte including halides of a metal selected from the alkali metals and the alkaline earth metals in contact with both the positive and negative electrodes. The current collector has a base metal of copper, silver, gold, aluminum or alloys thereof with a coating thereon of iron, nickel, chromium or alloys thereof. The current collector when subjected to cell voltage forms a sulfur-containing compound on the surface thereby substantially protecting the current collector from further attack by sulfur ions during cell operation. Both electroless and electrolytic processes may be used to deposit coatings.

Abstract: Alkali metal based electrochemical cells offer a great deal of promise for applications in many areas such as electric vehicles and load leveling purposes in stationary power plants. Lithium is an attractive candidate as the electroactive species in such cells since lithium is very electropositive, abundant and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and normally is operated at elevated temperatures. The subject invention provides an electrochemical cell in one embodiment of which lithium is the electroactive species. The cell comprises an electrolyte, a positive electrode, and a negative electrode, either or both of which is an all-solid, composite microstructural electrode containing both a reactant phase and a mixed ionic-electronic conducting phase. The cells of the subject invention exhibit improved kinetic features, current and power densities. Repeated charging and discharging of these cells can be accomplished without appreciable loss of capacity.

Abstract: Thermal insulation, especially for high-temperature batteries, wherein the thermal insulation has at least one hermetically sealed cavity which contains insulating material, characterized by the feature that the cavity is evacuated and is completely filled with at least one very fine insulating material in powder form in such manner that at least one first region of the cavity can be loaded with full pressure over the area and at least one second region of the cavity has very low thermal conductivity, and that these two regions are arranged immediately adjacent to each other.

Abstract: A thermally activated electrochemical cell is provided having a low melting oint electrolyte. The electrolyte is composed of a layer of a mixture of lithium perchlorate and lithium nitrate adjacent the anode and of a layer of a mixture of lithium perchlorate, lithium nitrate, and silver nitrate adjacent the cathode of the cell.

Abstract: A DC power source for use in a wide range of variable temperatures employing a battery having the characteristic that it is substantially dormant at normal ambient temperatures and operable only at temperatures substantially above normal ambient temperatures, including a heat retaining housing in which the battery is positioned and a controllable heat source within the housing to maintain the temperature of the battery within a preselected elevated range corresponding to the effective operating temperature characteristics of the battery.

Abstract: The efficiency of thermal galvanic cells is enhanced by establishing a temperature gradient along the electrodes, in addition to the temperature gradient between the electrodes, and/or by optimizing electrode geometry. Optimization of electrode geometry may comprise segmenting the electrodes while retaining the desired total electrode area or controlling the depth of immersion of the electrodes into the electrolyte. Further performance improvement may be obtained through the addition of a silica containing material and/or a thermal barrier to the electrolyte.

Abstract: A method of forming a component for a high-temperature secondary electrochemical cell having a positive electrode including a sulfide selected from the group consisting of iron sulfides, nickel sulfides, copper sulfides and cobalt sulfides, a negative electrode including an alloy of aluminum and an electrically insulating porous separator between said electrodes. The improvement comprises forming a slurry of solid particles dispersed in a liquid electrolyte such as the lithium chloride-potassium chloride eutetic, casting the slurry into a form having the shape of one of the components and smoothing the exposed surface of the slurry, cooling the cast slurry to form the solid component, and removing same. Electrodes and separators can be thus formed.

Abstract: The present invention is directed to rechargeable current-producing cell comprising:(a) an anode made by an alkali or an earth-alkali metal;(b) a non-aqueous electrolyte solution;(c) a cathode formed by alkali metal salts of chromium dichalcogenides of general formula M'.sub.x M".sub.y CrB.sub.2, wherein M' and M" are metals of group I A of the Periodic Table, B is a chalcogen and x and y have values between zero and one.

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: The invention comprises thermal batteries employing an FeS.sub.2 depolarizer, i.e. cathode material, and the depolarizer itself. A minor amount of CaSi.sub.2 preferably, 1-3% by weight is provided as an additive in the FeS.sub.2 depolarizer to eliminate the voltage transient (spike) which normally occurs upon activation of batteries of this type. The amount of FeS.sub.2 by weight generally comprises 64-90%.

Abstract: The efficiency of thermal galvanic cells is enhanced by establishing a temperature gradient along the electrodes, in addition to the temperature gradient between the electrodes, and/or by optimizing electrode geometry. Optimization of electrode geometry may comprise segmenting the electrodes while retaining the desired total electrode area or controlling the depth of immersion of the electrodes into the electrolyte. Further performance improvement may be obtained through the addition of a silica containing material and/or a thermal barrier to the electrolyte.

Abstract: A felt or other fabric of boron nitride suitable for use as an interelecte separator within an electrochemical cell is wetted with a solution containing a thermally decomposable organic salt of an alkaline earth metal. An aqueous solution of magnesium acetate is the preferred solution for this purpose. After wetting the boron nitride, the solution is dried by heating at a sufficiently low temperature to prevent rapid boiling and the creation of voids within the separator. The dried material is then calcined at an elevated temperature in excess of 400.degree. C. to provide a coating of an oxide of magnesium on the surface of the boron nitride fibers. A fabric or felt of boron nitride treated in this manner is easily wetted by molten electrolytic salts, such as the alkali metal halides or alkaline earth metal halides, that are used in high temperature, secondary electrochemical cells.

Abstract: A tubular high-temperature storage cell is provided. This cell comprises a central rod electrode of one polarity and a second electrode which encases said central electrode. Between both electrodes, a large separator is interposed. One electrical terminal from the central rod electrode is provided at the center of the cell top through a feedthrough sleeve. The opposite terminal is welded directly to the cell container can or to the cell top lid. The cell container itself also can act as a current collector.

Abstract: This invention relates to lithium-germanium containing electrodes for electrical energy storage batteries, batteries containing such electrodes and a process for fabrication of such electrodes from materials in the charged and uncharged state. The electro-chemically active material may be a binary alloy of lithium-germanium or ternary alloys of lithium-germanium-silicon and lithium-germanium-aluminum. Negative electrodes for electrical storage batteries fabricated according to this invention provide batteries having improved stability over prior art lithium containing electrodes and provides a particularly advantageous negative electrode for use in lithium-metal sulfide batteries having improved stability.

Abstract: A process for making laminates of cellophane, conductive plastic, and metal powder, comprising laminating the sheet of cellophane to a sheet of conductive plastic with an intermediate composition comprising an aqueous dispersion of metal electrode particles and a binder, and drying the laminate to remove water from the dispersion.

Abstract: Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and of light weight. One type of lithium-based cell utilizes a molten salt electrolyte and normally is operated in the temperature range of about 350.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems. The present invention provides an electrochemical cell in which lithium is the electroactive species. The cell has a positive electrode which includes a ternary compound generally represented as Li-M-O, wherein M is a transition metal. Corrosion of the inventive cell is considerably reduced.

Abstract: In a method of regulating the temperature of a system in which exothermic type reactions take place at temperatures of several hundreds of degrees and which are followed by stoppage periods, the system (1) is put in contact with a first substance (4) whose boiling temperature (T2) is close to the required temperature (T) of the system, and heat which results from the exothermic reactions is used to boil the first substance (4). Thereafter heat which comes from the condensation of the vapor evolved by said boiling is used to heat a second substance (5) to its melting point (T1), the second substance (5) being chosen so that it melts at a temperature close to but lower than the boiling temperature (T2) of the first substance (4). In operation the second substance (5) is kept at a temperature which is substantially constant and a little higher than its melting point (T1) until the end of a period of exothermic reaction.

Abstract: This invention is directed toward a seal (25) for fused salt batteries (10) having a current conducting rod (19) partially within said battery and partially outside which includes a layer of compressible material (32) on the body of the current conducting rod leaving exposed the opposite ends thereof and a swaged metal sheath (33) covering and compressing the layer of material to approximately its maximum density. Optionally, a sealing glass (35) having a low coefficient of thermal expansion approximating that of the current conducting rod and the metal sheath can also be employed over the end of the rod and/or a plating (31) of a conductive metal can be provided over the end of the current conducting rod outside of the battery and/or a separate coating (28) of a different material can be deposited on the rod between the rod and the layer of compressible material. A process is also provided for forming the seal.

Abstract: A secondary electrochemical cell and a negative electrode composition for use therewith comprising a positive electrode containing an active material of a chalcogen or a transiton metal chalcogenide, a negative electrode containing a lithium-aluminum alloy and an amount of a ternary alloy sufficient to provide at least about 5 percent overcharge capacity relative to a negative electrode solely of the lithium-aluminum alloy, the ternary alloy comprising lithium, aluminum, and iron or cobalt, and an electrolyte containing lithium ions in contact with both of the positive and the negative electrodes. The ternary alloy is present in the electrode in the range of from about 5 percent to about 50 percent by weight of the electrode composition and may include lithium-aluminum-nickel alloy in combination with either the ternary iron or cobalt alloys. A plurality of series connected cells having overcharge capacity can be equalized on the discharge side without expensive electrical equipment.

Abstract: Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

Abstract: A secondary electrochemical cell is prepared by providing positive and negative electrodes having outer enclosures of rigid perforated electrically conductive material defining an internal compartment containing the electrode material in porous solid form. The electrodes are each immersed in molten electrolyte salt prior to cell assembly to incorporate the cell electrolyte. Following solidification of the electrolyte substantially throughout the porous volume of the electrode material, the electrodes are arranged in an alternating positive-negative array with interelectrode separators of porous frangible electrically insulative material. The completed array is assembled into the cell housing and sealed such that on heating the solidified electrolyte flows into the interelectrode separator.

Abstract: An energy conversion process for converting thermal energy into stored electrochemical energy and then into electrical energy comprising heating a first FeCl.sub.2 -containing electrolyte melt to produce gaseous FeCl.sub.3 and a reductant product in a first chemical reaction, these reaction products being separated, cooled, optionally stored, and combined in a second FeCl.sub.2 -containing electrolyte melt to cause a reaction to take place which is the reverse of said first reaction, thereby regenerating said first melt and producing heat and electrical energy.

Abstract: A secondary electric cell which includes: a non-aqueous electrolyte, a negative electrode whose active material includes at least one alkali metal in contact with the electrolyte, and a positive electrode whose active material is suitable for intercalating the active material of the negative electrode, wherein said positive electrode includes an active compound or solid solution whose general formula is M.sub.x X, R.sub.y X.sub.3 where:M is an element chosen from lead and tin;R is an element chosen from bismuth and antimony; andX is an element chosen from sulphur and selenium, with x having a value lying between 0 and 1 (inclusive), and y having a value lying between 0 and 2 (inclusive). Such cells may be used in watches or pacemakers.

Abstract: An electrode structure for a secondary electrochemical cell includes an outer enclosure defining a compartment containing electrochemical active material. The enclosure includes a rigid electrically conductive metal sheet with perforated openings over major side surfaces. The enclosure can be assembled as first and second trays each with a rigid sheet of perforated electrically conductive metal at major side surfaces and normally extending flanges at parametric margins. The trays can be pressed together with moldable active material between the two to form an expandable electrode. A plurality of positive and negative electrodes thus formed are arranged in an alternating array with porous frangible interelectrode separators within the housing of the secondary electrochemical cell.

Abstract: A molten salt cell is described in which a special material is used as the active material in the negative electrode. Such active material permits extensive cycling of the battery and does not significantly alter cell voltage. Molten salt cells made in accordance with this invention exhibit high energy content and high discharge rates. In addition, they can be cycled extensively without significant loss of capacity.

Abstract: A system and method for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 Kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

Abstract: An electrolyte for use in an electrochemical cell is disclosed of the alkali metal-aluminium-halide type. The electrolyte has a melting point below 140.degree. C. at atmospheric pressure and conforms with the stoichiometric productMAlX.sub.4whereinM represents lithium cations, a mixture of lithium and potassium cations or a mixture of sodium and potassium cations; andX represents a mixture of chloride and fluoride anions.A method of reducing the melting point of a sodium-aluminium-chloride or lithium-aluminium-chloride electrolyte by doping it with a potassium fluoride, sodium fluoride, or lithium fluoride, to obtain said electrolyte with a melting point below 140.degree. C. is disclosed, as are various electrochemical cells employing the product electrolyte.

Abstract: An electrode for an electrochemical cell, the electrode comprising an electrochemically active substance selected from:(a) the group comprising or including the halogens, the alkali metals, the alkaline earth metals the first and second series of transition elements, lead, phosphorus, arsenic, antimony, bismuth, and aluminium;(b) an oxygen, sulphur or selenium composition; or(c) a composition containing carbon, baron, silicon or nitrogen with any of the substances of (a) or (b);and a zeolite molecular sieve carrier wherein the electrochemically active substance is sorbed and is held in dispersed form for effective use in a cell. An electrochemical cell including a pair of electrodes and an electrolyte, at least one electrode comprising an electrode as defined above.

Abstract: In a high-temperature cell using, for example, the system Li(Al)/LiCl, KCl/MeS (wherein Me is a heavy metal) the operating temperatures and the composition of the molten electrolyte are so selected that a solid phase is created through partial precipitation of at least one of the components of the salt mixture, which provides the separator function between the electrode plates. For example, a non-eutectically composed molten electrolyte of 80% by volume LiCl and 20% by volume KCl, at a given temperature corresponding to the operating point in the phase diagram, contains a solid LiCl frame whose pore volume of about 50% is filled with ion-conducting residual molten LiCl and KCl. Through combination with non-electron conducting inert material in grid or powder form, the permeability of the precipitated solid separator can be further controlled.

Abstract: A thermal battery cell is provided comprising a low-melting point electroe in the presence of halides, a cathode, an oxidizer and a calcium anode.

Abstract: A sodium-sulfur battery including sodium and sulfur separated by a beta-alumina tube is disclosed herein along with a method of operating the battery utilizing a sodium storage and dispensing arrangement. This storage and dispensing arrangement includes a housing containing a supply of sodium out of contact with the beta-alumina tube and a thermally responsive bimetallic valve for passing sodium from its supply housing into contact with the beta-alumina separating tube when the sodium is in a liquid state and so long as the average temperature along at least a predetermined section of the tube remains below a predetermined value. In the event that this average temperature reaches the predetermined value, the bimetallic valve automatically prevents passage of liquid sodium from its supply housing to the beta-alumina tube.

Abstract: Separators for electrochemical high temperature cells with molten electrolytes, particularly consisting of the raw materials boron nitride or aluminum nitride, become better wettable through treatment with boron trifluoride. Preferably the separator, e.g. a BN fabric, may be sprinkled with a BF.sub.3 yielding material, e.g. KBF.sub.4 and activated through brief heating to about 400.degree. C.

Abstract: Electrochemical storage battery normally operating at an elevated temperature, surrounded by heat insulation to retard heat loss. The surrounding heat insulation is an enclosed gastight cavity under subatmospheric pressure to impede heat flow by convection, and a radiation shield in the interior of the cavity in the path of heat flow to reduce heat loss by radiation.

Abstract: A battery includes a negative electrode comprising metallic lithium (Li) in conjunction with lithium chlorate (LiClO.sub.3) electrolyte. Lithium perchlorate (LiClO.sub.4) may also be used as the electrolyte. Lithium chloride (LiCl) and lithium oxide (Li.sub.2 O), individually or together, may also be utilized with lithium chlorate or lithium perchlorate in forming the electrolyte. A positive electrode comprises a metal, such as nickel. In one form, a sheet of lithium metal is sandwiched between two sheets of nickel comprising a negative electrode, one nickel sheet being perforated to permit contact between the lithium sheet and a lithium chlorate electrolyte contained within an insulative member, the other electrode comprising a film of metallic nickel disposed upon the insulative member and in contact with the electrolyte; alternatively, a film or sheet of lithium metal may be disposed upon the insulator as a negative electrode.

Abstract: An electrode for a high temperature secondary electrical storage cell including an alkali metal negative electrode, a molten salt electrolyte, and a transition metal sulfide as the positive electrode, formed by mechanically loading a precut form or graphite felt or foam with FeS.sub.x powder, coating or impregnating the precut form with a high carbon yield resin, curing the resin at an intermediate temperature, and carbonizing the resin at a temperature below 1000.degree. C.

Abstract: The rechargeable electrical energy storage device including spaced-apart negative electrode and positive electrode structures immersed in an electrolyte which is molten at the operating temperature of the device wherein the positive electrode structure comprises a housing for containing a body of electropositive active material, said housing having at least one open face, an electrolyte permeable member affixed to the housing and covering said open face for retaining said active material in said housing and said housing and electrolyte permeable member comprising material selected from the group consisting of steel, nickel, copper and alloys thereof having at least an 8 .mu.m thick electroless nickel coating thereon. In accordance with the present invention it has been found that such an electroless nickel coating permits the use of relatively inexpensive conductive materials such as steel, nickel, copper and alloys thereof and provides the corrosion resistance required in the molten electrolyte.

Abstract: The invention relates to an iron/lithium anode material for use in thermal batteries which comprises about 15% to 30% by weight lithium. Thermal batteries made from such anodes are also disclosed. The anode comprises particulate iron bound together by the surface tension of the lithium which wets the iron particles. A method is disclosed for the manufacture of the anode material which includes adding iron powder to a molten lithium and mixing to form a homogeneous mixture. The mixture is cooled to form an ingot and rolled into strips for fabrication into anode configurations.

Abstract: Electrolyte geometry in alkali metal thermoelectric generator devices that alters the view thereof seen by cooler condenser regions provides an increase in power generating area without undesirably concomitant increase in radiation heat transfer area.

Abstract: A thermoelectric energy system comprising first and second separated metal electrodes, an electrolyte comprising a source of metal ions and a material for complexing the metal ions to form a metal ion complex, the electrolyte being disposed between and in contact with the electrodes to provide a metal ion conduction path which extends substantially the entire distance between the electrodes. A temperature gradient is imposed between the electrodes to produce a voltage across the electrodes. An electric circuit is connected to the electrodes to allow for removal of electrical energy from the system.

Abstract: A secondary bipolar battery including a conductive intercell barrier having a tortuously-pathed (e.g., finned) peripheral portion outboard the cells to reduce parasitic current flow between adjacent cells around the periphery of the barrier. The battery's end electrodes have greater reactant content than the intermediate electrodes to compensate for parasitic losses. A Li/FeS.sub.2 example is detailed.

Abstract: A pelletized, light weight, thermal battery having copper (II) chloride and an alkali tetrachloroaluminate as electrolytic components.

Abstract: Molten sodium is filled into a reservoir insert container including a closed ended tubular portion and the sodium is solidified and the container sealed. Then the container is placed into the sodium compartment of a sodium sulfur cell so that the tubular portion extends into the electrolytic separator tube of the cell and is spaced apart therefrom forming an annular chamber. To activate the cell, the sodium is melted and an opening is formed in the insert container permitting flow of molten sodium from the container into the thus-formed chamber.

Abstract: A thermal battery using a calcium anode and a catholyte consisting of a mure of lithium, potassium, nitrate and chloride ions. The device is operable over a temperature range of about 150.degree. C. to 600.degree. C. and produces a long lasting, high energy density output.

Abstract: Electrochemical cell components such as interelectrode separators, retaining screens and current collectors are contacted with lithium tetrachloroaluminate prior to contact with molten electrolytic salt to improve electrolyte wetting. The LiAlCl.sub.4 can be applied in powdered, molten or solution form but, since this material has a lower melting point than the electrolytic salt used in high-temperature cells, the powdered LiAlCl.sub.4 forms a molten flux prior to contact by the molten electrolyte when both materials are initially provided in solid form. Components of materials such as boron nitride and other materials which are difficult to wet with molten salts are advantageously treated by this process.

Abstract: A calcium electrode for an electrochemical cell with an electrolyte consing of molten nitrates and up to 10 mole percent halides.

Abstract: Molten sodium is filled into a reservoir insert container including a closed ended tubular portion and the sodium is solidified and the container sealed. Then an open port is provided for the insert container. The container is placed into the sodium compartment of a sodium-sulfur cell so that the tubular portion extends into the electrolytic separator tube of the cell and is spaced apart therefrom forming an annular chamber. To activate the cell, the sodium is melted and flows through the open port into the annular chamber.

Abstract: A high temperature secondary cell of pelletized construction contained within a close fitting inert tube. Anode active material is lithium. Cathode active material is an iron sulphide or titanium disulphide. Electrolyte is a mixture of lithium halides. The cell is bounded by separator plates extending beyond the inner peripheral surface of the inert tube.