Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
  • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
  • C04B35/10—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
  • C04B35/111—Fine ceramics
  • C04B35/113—Fine ceramics based on beta-aluminium oxide
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/183—Sealing members
  • H01M50/19—Sealing members characterised by the material
  • H01M50/191—Inorganic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/36—Accumulators not provided for in groups H01M10/05-H01M10/34
  • H01M10/39—Accumulators not provided for in groups H01M10/05-H01M10/34 working at high temperature
  • H01M10/3909—Sodium-sulfur cells
  • H01M10/3918—Sodium-sulfur cells characterised by the electrolyte
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the invention relates to a high-energy secondary battery cell with a housing in which there is a solid electrolyte made of good ion-conducting aluminum oxide ceramic, which separates the inside of the cell into a positive and a negative electrode and with an electrically conductive housing part of the positive and negative Electrode is connected.
• High energy secondary batteries such as Na / S batteries or zebra batteries use a ceramic electrolyte to separate the positive and negative electrodes.
• Sodium-ion-conducting aluminum oxide is used as the electrolytic ceramic. This ceramic must be firmly bonded to the housing. to create two completely separate spaces for the positive electrode on the one hand and for the negative electrode on the other.
• a U-tubular electrolyte is used, which is introduced into a cylindrical housing and is connected directly to the housing via a metal-ceramic connection. The interior in the U-tube is firmly closed by a cover, which cover is also firmly connected to the electrolyte ceramic by a metal-ceramic connection.
• the solid electrolyte must have a low electrical resistance. Since the solid electrolyte is a polycrystalline material, the internal crystal and the resistance between the crystals must be low.
• connections of the electrolyte ceramic to the housing on the one hand or the cover on the other hand cannot be used directly as metal ceramic connections -Ceramic are executed -. Rather, in a known high-energy secondary battery, a transition is formed in such a way that an additional CL-Al oxide ring is inserted, that is to say that the ⁇ -AIL oxide ring is placed on the upper edge of the U-tube as an intermediate piece and over a special glass through a melting process connected to the / ⁇ ceramic.
• the lid and housing which also represent the two poles of the cell, are made of two metal ceramic connectors. connected to the. ⁇ - ring.
• the r ⁇ -A l-Ox i dri ng t then runs the + pole from the -Pol the cell. (GB-A-2190 236)
• the ⁇ -ceramic is clamped with the glass ring through a pressure seal between the housing and cover.
• the housing and cover in turn represent the two poles of the cell.
• a high-energy secondary battery cell with a housing and a solid electrolyte arranged therein, consisting of good ion-conducting i-aluminum oxide ceramic, which on its side facing a housing part is connected to the housing part via an intermediate layer (US-A-4131 694 ).
• This intermediate layer consists of aluminum oxide ceramic, in which the sodium ions are exchanged for divalent other ions.
• the layer is produced by immersing the solid electrolyte in a salt bath with the divalent ions. This creates the approximately 10 ⁇ m thick intermediate layer of other conductivity, which is based on the partial exchange of the sodium ions for the foreign ions. Sodium ions remain in the layer, which continue to cause conductivity.
• the invention has for its object to develop such a high-energy secondary battery cell, which contains a solid electrolyte made of highly ion-conducting ⁇ -alumina ceramic, which separates the inside of the cell into a positive and a negative electrode, in such a way that between the solid electrolyte and the metallic Housing part has a well electrically insulating, temperature-resistant and longer life connection.
• the object is achieved in that the intermediate piece consists of less conductive J-aluminum oxide ceramic.
• High-energy secondary battery cell which has an intermediate layer in the area of the connection point, the object is achieved according to the invention in that the intermediate layer is formed as a coating of magnesium oxide or silicon dioxide.
• the non-conductive or poorly conductive / 3 ceramic is produced by changing the composition of the beta ceramic.
• the proportion of stabilizing ions required can be reduced from the usual 0.7 to 0.2 or 0.1% by weight of lithium oxide.
• the resistance of a mass containing 0.2% lithium oxide is 15 .5-2'cm at 275 C, while the mass containing 0.7% lithium oxide has only 8 J -_- cm.
• a further increase in resistance can be achieved by inserting a boehmite that is not well crystalline, for example Bacasol from BA Chemicals, into the raw material.
• the material made from a well crystalline boehmite has a resistance of 8 -52 * cm at 275 C C, while a material prepared from Bacasol raw material has 4.25 ⁇ - cm.
• Another possibility is to produce, which is completely doped with magnesium oxide or lithium oxide.
• Such a substance has the formula Na 2 gAl ⁇ 0 0i7 - this substance has no gaps in the sodium conducting level, so that the sodium ion diffusion is severely hindered.
• the resistance of a fy'-alumina solid electrolyte can be increased by blocking the sodium ion diffusion at the grain boundaries.
• a number of foreign substances in the raw material can increase the resistance of the aluminum oxide pellets.
• the two most important are calcium oxide and silicon oxide.
• calcium oxide additives the formation of intercrystalline calcium aluminate phases has hindered the migration of mobile sodium ions to such an extent that the measured one Resistance increased exponentially with the calcium content at 300 ° C.
• silicon oxide the addition of a few percent by weight increased the resistance of ⁇ -aluminum oxide by a factor of 10. A similar effect can be observed if silicon oxide is used for doping "aluminum.
• the sodium ions are ion exchangeable in the c "alumina.
• Many different (V'-alumina were made by ion exchange with molten salts.
• the sodium - ⁇ '- alumina has the lowest ionic resistance of all, but the exchange of a small amount of sodium for a slower moving one ion reduces the sodium mobility. the total resistance can thereby be higher than that of the fully exchanged material with slow mobile ions. Therefore, an increase in resistance by replacing a low sodium content to a large 1 + ion, for example, cesium, or a 2 + Ion, for example barium, strontium or calcium, or a 3 i ion, for example the rare earths.
• the direct generation of the mixed sodium "-aluminium oxide is preferred here, for example La 3+ - o" -aluminium oxides produced by direct sintering.
• one or more of the methods described above may be used in any combination.
• the method selected may depend on whether a part is made and sintered with the beta alumina during firing or whether one two-step joining method is used to press the two objects together, and the high resistance material can also be applied to the edge of the solid electrolyte as a coating or screen printed product.
• the material that changes the resistance can be used for the coating of material with high resistance.
• the cover therefore needs not being of the i "type of alumina, it may contain just those impurities that block the grain boundary path and / or increase the doping level and / or introduce slower moving ions. This alters the / 3" alumina on the surface of its edges to so to increase the resistance of the material at the edges.
• the first is the production of a solid electrolyte from / -. "-Alumina and a ring made of a modified ⁇ >" - alumina with high resistance and the connection of these two parts.
• the second is to make a solid electrolyte and then increase the resistance at the edges.
• the third is to manufacture tools for a dry press or automatic press, which allow the ceramic product to be pressed in one process step.
• a solid "aluminum oxide" electrolyte disk can be made by a number of processes, the simplest of which is pressing in an automatic press. The blanks from this process provide flat surfaces.
• the ring made from modified ⁇ "aluminum oxide can also be pressed an automatic press, using an appropriate shape. In order to improve the flatness of the surfaces to be connected to one another, processing in the raw state can be carried out.
• the ring made of modified / T'-aluminum oxide and the solid electrolyte which, apart from being disc-shaped, for example, also cylindrical, for example, by sintering, the ring is placed on the solid electrolyte. There are two ways to burn the two parts:
• both parts are sintered together, whereby a suitable refractory material can be placed on the upper end of the ring in order to improve the sintering together due to a weight load.
• the weight of the solid electrolyte can support the sintering together. If the weight of the solid electrolyte If an additional weight is not sufficient, for example a suitable refractory material.
• the ring and the disk-shaped solid electrolyte can also be produced by the rolling process, continuous casting process and by extrusion.
• the ring shape is particularly suitable for the extrusion process, although problems may arise when cutting the extruded piece.
• the continuous casting process or rolling can be used to produce a disk-shaped solid electrolyte.
• a higher level of the binder is used. Either by applying pressure in the presence of heat or by using a solvent for the binder, two parts can be joined together as blanks. Therefore, there is rather a hermetic connection between the solid electrolyte and the ring.
• the application of a high-resistance coating requires the production of a coating material and the application of the coating.
• the solid electrolyte can be produced by any of the methods described above.
• the coating is generally made by a wet process whereby the ingredients for the coating are milled with a suitable liquid (usually water).
• a suitable liquid usually water.
• the coating is preferably applied by brushing, but spraying or dipping can also be used. When spraying or dipping, the area of the 3 "aluminum oxide that is not to be coated must be covered.
• the coating can also be applied as a dry powder that is evenly distributed on the surface. When fired, the powder melts and adheres to the surface.
• Other methods of applying a high-resistance coating to a ceramic body are electrophoretic deposition and chemical deposition, but these methods are more complex than the wet method.
• the ceramic body After the coating has been applied, the ceramic body is left to dry, if necessary, and then fired in an oven in the customary manner.
• the ceramic body With carefully designed tools for dry pressing or die casting, it is possible to manufacture the ceramic body in a single operation. There are two filling openings, one for the "- Aluminum oxide powder and one for the modified 3 "aluminum oxide powder.
• the procedure is as follows: First the ring part of the mold is filled and then the disc part. Then pressure is exerted on the mold content, so that the two parts not only solidify but also The individual raw body can then be sintered in a suitable furnace using kiln furniture.
• - aluminum oxide powder not only refers to / s" aluminum oxide powder, but also to powder which, when fired, converts to a V'-aluminum oxide ceramic.
• modified "alumina powder refers not only to a powder that is a modified /" -A - um ".r ⁇ ump powder, but also to a powder that turns into a modified / V'-alumina powder when fired and is non-conductive or is poorly conductive.
• the firing of all components takes place at a firing temperature that gives a product with sufficient density and is carried out in a suitable firing aid.
• Figure 1 shows a part of a high energy secondary battery cell in longitudinal section
• Figure 2 shows a part of another embodiment of a
• High energy secondary battery cell in longitudinal section is High energy secondary battery cell in longitudinal section.
• a Hochenergiesekundärbatte ⁇ ' ezelle contains a good ion-conductive cylindrical solid electrolyte 1 made of -Al-oxide ceramic, one end 2 of which is connected to a less conductive, for example annular, intermediate piece 3 made of little or non-conductive (j-Al-oxide ceramic).
• the intermediate piece 3 is connected at its end 4 facing away from the solid electrolyte to a cover 5, which is made of metal, for example From the end 4, extending radially outwards, a metal ring 6 is fastened to the intermediate piece 3, which is part of the housing and is connected to a cylindrical housing section 7.
• the cover 5 is also part of the housing.
• the solid electrolyte 1 separates the positive 8 and negative 9 electrodes within the cell.
• the electrode 9 consists, for example, of sodium.
• FIG. 2 shows an embodiment in which a solid electrolyte 1 made of highly ion-conductive aluminum oxide ceramic is provided with a low or non-conductive coating 10 on and near its ends.
• the cover 5 and the metal ring 6 are connected to the coating 10. Otherwise, the arrangement according to FIG. 2 corresponds to that of FIG. 1.
• the procedure is such that the highly conductive electrolyte ceramic is pressed in the known manner in the form of a disk, a U-tube or a tube.
• the non-conductive or poorly conductive A ceramic is pressed into rings which have such a geometry that they can be connected to the edge zones of the highly conductive ceramic (FIG. 1).
• These poorly conductive - ceramic rings can be sintered extra; they are then provided with metal rings over a metal-ceramic connection.
• These rings of poorly conducting ⁇ ceramics are then connected to the well agendadenf ⁇ Kera roi k through a glass seal. 11
• the highly conductive ceramic to the poorly conductive ceramic, both in green condition, by pressing and then to sinter together.
• This electrolyte ceramic is provided in its poorly conductive edge zone with metal rings via a ceramic-metal connection.
• the electrolyte ceramics are attached to the two metal rings the housing, or with the cover, which represent the two poles, connected by welding.
• the highly conductive ß-electrolytic ceramic is manufactured in the usual way by pressing. This can take the form of disks, tubes or U-tubes.
• the ceramic produced in this way is provided with a coating of Mg oxide or Si dioxide in its edge area.
• This coating is produced by immersing the ceramic in a suspension of Mg oxide or Si dioxide in a liquid, for example water, with its edge zones one or more times. After drying and the subsequent firing at the usual production temperature of the ceramic, an electrolyte body is formed, the edge zones of which are poor or non-conductive.
• the two metal rings are attached to these edge zones by means of metal-ceramic connections which are produced using known techniques.
• the electrolyte ceramic is in turn connected to the housing and cover of the cell via the two metal rings. This is the case with tubular cells, with flat cells with disc-shaped electrolytes the two rings are welded to the two housing shells.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Inorganic Chemistry (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Secondary Cells (AREA)
• Compositions Of Oxide Ceramics (AREA)

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Cited By (12)

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Citations (8)

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• 1989
  • 1989-08-16 DE DE3926977A patent/DE3926977A1/de active Granted
• 1990
  • 1990-08-08 WO PCT/EP1990/001298 patent/WO1991003080A1/de not_active Ceased

Patent Citations (8)

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