FR2489603A1 - ELEMENT ELECTROCHEMICAL ACCUMULATOR - Google Patents

Abstract

THE INVENTION RELATES TO AN ELECTROCHEMICAL ACCUMULATOR ELEMENT. THIS ELECTROCHEMICAL ACCUMULATOR ELEMENT INCLUDES A METAL 1 FOR CONNECTION BETWEEN SEVERAL ELECTROCHEMICAL ELEMENTS, CONSTITUTED BY AT LEAST TWO ELECTRICALLY CONDUCTIVE LAYERS, SUPERIMPOSED 2, 3 OF WHICH AT LEAST ONE HAS LOW JUNCTIONING RESISTANCE AND MOUNTAINABILITY IS CORROSION-RESISTANT AND HAS LOW OHMIC RESISTANCE, THE ELECTRICAL CONNECTION SURFACES 4 OF UNIT 1 BEING CONSTITUTED AT LEAST BY ONE OF THE TWO LAYERS 2, 3. APPLICATION IN PARTICULAR TO OXIDIZATION-FREE ACCUMULATOR BATTERIES.

Description

The invention relates to an electrochemical accumulator element

  the base of an alkali metal and a chalcogen, comprising at least one anode space for receiving the anolyte and a cathode space for receiving the catholyte and which are separated from each other

  by a wall formed of an electrolyte-solid and conductive

  this for alkaline ions = and are limited at least partially-

  by a metal wall, a first current draw member being constituted by an electrode introduced into the space of the reagent product, limited by

  the wall formed by the solid electrolyte, while a se-

  current draw device is formed by the metal wall, and that each current drawing member can be connected to at least one metal member connecting elements, for connecting in an electrically conductive manner the accumulator element to the

  minus another accumulator element.

  Such electrochemical accumulator elements

  rechargeable batteries with solid electrolytes

  are very good for the realization of accumulators

  with a high density of energy and power.

  The solid electrolyte used, for example, in the case of sodium / sulfur storage elements and consisting of beta-aluminum oxide allows only sodium ions to pass. In contrast to the lead-acid accumulator 2, this means that virtually no self-discharge occurs and that, during charging, no secondary reaction takes place, such as water dissociation in the case of the system. lead-lead oxide. The current efficiency, that is, the Faradays efficiency of such a sodium / sulfur accumulator element, is

around 100%.

  To produce such a storage battery, several sodium / sulfur accumulators are connected in parallel. Several groups of this type of accumulator elements connected in parallel are then mounted in

  series. Thanks to this arrangement, within a group

  killed by several accumulators connected in parallel, it establishes the same state of charge in all the accumulators, because of currents of

  compensation circulating between these accumulators.

  From a statistical point of view, the overall capacities of the different groups differ less from each other.

  other than the capacities of individual accumulators

  duels. To achieve such a parallel assembly, which includes several storage elements of this type, is connected in an electrically conductive manner each

  accumulator element provided for this purpose in two or more

  accumulators mounted in parallel with this element

  accumulator. For this purpose, special organs are

  tionally designed connection between accumulators

  tors. Conductor is connected in a conductive manner for storage elements to the two cathodic and anodic current drawing members of the two

  accumulators to be interconnected.

  To assemble the battery packs

  bent up to now, connecting members are used between accumulators, for which copper is used as the base material. These connection elements are covered with aluminum to protect them against

all corrosion and oxidation.

  The deposition of aluminum is by plasma projection. For the establishment of the electrical contact with the accumulator element, it is preferably fixed by

  screwing the connecting members between accumula-

  on these. The screwing technique however has

  for the inconvenience that copper, used for

  connection of the connection element between accumulator elements,

  and aluminum soften under pressure at room temperature.

  operating condition of the accumulator element, which is

  between 300 and 400C. This means that these materials

  are subject to creep or deformation at the temperature

  indicated above. As a result, there is an inadmissible increase in the resistance at the electrical connection surfaces of the connecting member between accumulator elements. The correct operation of a battery, the accumulators of which are connected together through these organs

connection is therefore excluded.

  Therefore, the object of the present invention is to create a connection member between accumulator elements having a very low ohmic resistance and which remains free of oxidation layers even in the case of a

  long-term operation and whose electrical resistance

  The junction box is not increased even in the case of an average operating temperature of 400 ° C. The organ

  connection between accumulators must therefore

  be so constituted that it can be fixed at

  remains or removably to an accumulator element.

  This problem is solved by the fact that

  The metallic connection between accumulators is at least locally composed of two or more electrically conductive layers, at least partially arranged one above the other, and of which at least one first layer has a low resistance of junction and a

  defined mechanical stability and at least one second -

  layer is resistant to oxidation and has a low ohmic resistance, and that the connecting surfaces

  electrical connection of the connecting element between

  The emateurs are at least one of two layers. The connecting member between accumulator elements has the form of a band. The latter is performed at least in zones with two or more layers. A

  first layer is formed by a steel strip. The se-

  layer is made of aluminum which is

  deposited by plasma projection on the steel strip.

  The second layer may also be formed by an aluminum strip which is laminated on the strip

  steel. In the case of aluminum, this is a material

  very light. In addition, it has the property of not having any oxidation layer, even in the case of very long operating periods of the elements

  accumulators. In addition, the specific conductivity

  the weight due to aluminum is very large. It reaches 5.6 m.cm 3 / (ngmm) whereas in the case of copper, silver, gold, steel C and steel X, it only takes values between 2, 8 and

3 2

0.14 m.cm /(n.mm.g).

  The steel strip contributing to form the connecting member between accumulator elements has a very low junction resistance, which is less than 1 milliohm. In addition, the steel strip is sufficiently flexible, while giving the connecting member between accumulator elements the mechanical stability required of the latter. The connecting member between accumulator elements can, therefore, be simply connected permanently or removably to the current draw members of the accumulator element. In particular said connection member may be welded to the current draw members of the storage elements or be detachably attached to these current draw members. Advantageously, even in the case of a long-term operation and an average operating temperature of 300 to 4000 C, it has no

  softening under pressure and no increase in

  serve as its junction resistance. In the case of a

  normal temperature of about 20'C, it has a resistance

  connection temperature of 0.36 milliohm. In the case of a

  4000C operating temperature, the connection resistance

  increase slightly in accordance with the temperature coefficient of the specific resistances of the different

  connecting material between accumulators

  tors. The element connecting member according to the invention is formed by a steel strip which is covered on one of its faces or on both sides by an aluminum layer. The aluminum layer can

  be deposited by plasma projection or by

  immersion mining on the steel strip. Instead of this layer, one can also affix an aluminum strip on one side or on both sides of the strip

  steel. This is preferably done by means of a

  cage cold or hot. In addition, there is also the possibility of also welding such a strip of aluminum on one side or on both sides of the steel strip.

  According to another embodiment of the invention,

  the steel strip is provided on one of its faces or on both sides with an aluminum coating, only in its central or central zone. Its end surfaces that make up the electrical connection surfaces

  of the connecting element, are not covered by

  in the case of this embodiment. All connection elements of the elements, which must be screwed

  current drawers of accumulators

  latters, are provided with at least one eyelet, each at their electrical connection surfaces, that is to say in particular at their ends. To realize the

  screwing the connecting member between elements,

  a screw in each of these eyelets and rotate the respective current drawing member, with which the connecting member between elements must be connected

  in an electrically conductive manner.

  Another embodiment of the element connecting member according to the invention comprises two steel legs which are arranged at a reciprocal distance had to be predetermined. Steel legs

  are arranged in such a way that their longitudinal axes

  are in a plane. The interspace between

  these two steel legs are crossed by a strip of aluminum

  which is affixed to the two ends facing each other and is linked by force to these

  latest. Also in the case of this form of

  The two steel tabs again constitute the electrical connection surfaces of the connection member between elements. In the case where the connection member between elements must be fixed by screwing to the current drawing members,

  the legs are again equipped each with an eyelet.

  Another element connecting element according to the invention consists of two or more steel strips each of which is covered with aluminum on one of its faces or on both sides. These steel strips are arranged on one another by being stacked and are interconnected. The element connecting member according to the invention may also be constituted by a metal fabric. The latter is constituted for example by two

  reciprocally intertwined steel wires which are

  green aluminum. Both ends of this metallic fabric

  that are provided with respective steel sleeves constituting the electrical connection surfaces of the body of

connection between elements.

  By way of example, an embodiment of the subject of the invention has been described below and diagrammatically illustrated in the accompanying drawings, in which FIG. 1 represents a vertical section of a connection member between accumulator elements; Figure to represents the complete member of connection between elements, shown in Figure 1; FIG. 3 represents a connection element between elements covered on one side by aluminum.

  whose outer surfaces are made up of only

  by the ends of the steel strip; FIG. 4 represents a connection member

  between elements covered on both sides by aluminum

  minium; FIG. 5 represents a variant of the connection element between elements represented in FIG. 4; FIG. 6 represents a connecting element between elements constituted by two steel plates and by a

aluminum strip.

  Figure 7 shows another variant of the connection member between elements; Fig. 8 shows a member connecting member formed by a metal fabric; FIG. 9 represents two accumulator elements which are in mutual electrical contact via two connection members between elements according to the invention. In Figure 1, there is shown in a vertical sectional view the member 1, according to the invention, connection for accumulator elements. The cutting surface is parallel to the longitudinal axis of the connecting member 1. The latter is made in the form of a strip and is formed of two layers 2 and 3 planes arranged one above the other. The connecting member between accumulator elements consists essentially of a steel strip 2 and an aluminuim layer 3. The latter is applied to one side of the steel strip. Preferably, it is filed by

  plasma projection on the steel strip.

  In Figure 2, there is shown all of this connecting member between elements. In this figure

  it can be seen that the aluminum layer 3 covers completely

  one side of the steel strip. Instead of the aluminum layer deposited by plasma projection, it is also possible to affix an aluminum layer 3 on the steel strip. The binding of such an aluminum strip 3 to the steel strip 2 is effected for example by means of a

  cold or hot plating. Aluminum strip 3 can -

  also be attached by welding to the steel strip. The or-

  The connection between elements, according to the invention and shown in FIGS. 1 and 2, has a width close to 12 mm. In the case where the conditions so require,

  the steel strip 2 may also have other dimensions

  sions. The thickness of this steel strip 2 is located

between 0.1 and 5 mm.

  Most of the steel strips have a thickness of between 0.3 and 1 mm. The form of

  The preferred embodiment has a thickness of 0.6 mm.

  The length of the steel strip 2 is determined by the respective conditions, and in particular by the respective spacing between the two storage elements to be electrically connected. The aluminum layer 3 deposited on the steel strip 2 has a thickness of between about 0.01 and 11 mm. The preferred embodiment

  has a thickness of 0.6 mm. In order to obtain a conduc-

  optimal tiveness of the element 1 connection between elements

  accumulators, an aluminum layer 3 is

  thickness of 0.05 to 0.4 mm on the steel strip

  2. As already mentioned, to form the coating

  On the steel strip 2, it is also possible to use an aluminum strip 3 in place of a layer of aluminum deposited by plasma projection. The thickness of such an aluminum strip is preferably between 0.02 and

  0.6 mm. The member, according to the invention, of connection

  The elements are equipped with respective eyelets 5 on its two electrical connection surfaces 4, which are located on its two ends. These eyelets are used to

  to make a detachable fastening on the pre-

  current removal from the accumulator elements. In the case where the conditions so require, the element connecting member may also be fixed by screwing on a second connecting member between elements serving as an extension member. For screwing, is threaded into each eyelet the neck of a screw (here not shown), which is screwed for fixing in the current draw member of a storage element Figure 3 shows a variant of the organ 1

  connection between elements, shown in Figure 2.

  This member is constituted essentially as the member 1 for connection between elements shown in FIG.

  explained in the associated description. It involves again

  a steel strip 2 which has the indi-

  in the previous description. A diaper

  of aluminum or an aluminum sheet 3 is affixed again on one side of this steel strip 2. The aluminum layer 3 is here thicker than in the case of the embodiments described above. In contrast to the member connecting member shown in Figures 1 and 2, the aluminum layer 3 affixed to one side of the strip does not completely cover the steel strip 2. The aluminum layer 3 is preferably arranged only in the middle part of the strip

  of steel and has a length of about 30 to 100 mm.

  In the case of this embodiment of the organ

  connecting elements, the two connecting surfaces

  electrical equipment 4, which are located on both ends

  mites of the steel strip 2, have no coating.

  This embodiment of the connection element between elements is preferably used when the layer of aluminum 3 affixed is, as here, a thickness greater than 0.4 mm. This makes it possible to avoid creep of the aluminum in the area of the connection surface 4, in particular around the eyelets 5, in particular when the element connecting member is screwed onto the current drawers and the screws exert

  a pressure on said connecting member between elements.

  In contrast to this, the embodiment, shown in FIG. 2, of the element connecting member comprises an aluminum layer 3 which, as already mentioned, has an optimum thickness of between 0.05 and 0.4 mm. The steel strip 2 can be provided entirely with an aluminum coating in the case of the embodiment of the element connecting member, shown in Figure 2, since for such a layer thickness there is no creep backflow of aluminum at temperatures around 400 ° C. Such an aluminum layer is also not affected by the pressure load

applied by the screws.

  FIG. 4 also shows an embodiment of the connection element between elements,

  according to the invention. This connection member is constituted

  killed by a steel strip 2 which has a coating on both sides. This coating is formed by a layer of aluminum 3. As already mentioned above, these two aluminum layers can be deposited by plasma projection or

  by aluminising with imersion on the surface of the steel strip. The dimensions

  the steel strip 2 correspond to the dimensions of the steel strip 2

  represented in FIG. 2 and explained in the description

  associated. In the case of the embodiment

  4, instead of using both, aluminum layers 3 deposited for example by projection

  plasma, two bands of aluminum can also be

  to the surfaces of the steel strip. The two aluminum strips are connected for example by the steel strip 2 by means of cold or hot plating. A welding of

  the steel strip 2 to the two aluminum strips is also

  possible. The dimensions of the two layers or bands

  3 are chosen in such a way that the two

  faces of the steel strip 2 overlap completely.

  The thickness of the two aluminum layers or strips corre-

  to the values described above. In the vicinity of its two electrical connection surfaces, the body of

  connection between elements is equipped with eyelets 5 of mania-

re to allow screwing.

  Figure 5 shows a variant of the organ of

  connection between elements 1, shown in FIG.

  The constitution of this element connecting member differs only slightly from the embodiment shown in Figure 4. This element connecting member 1 is also formed essentially by a

  strip of steel, on both sides of which is again

  This layer is again here two aluminum layers or strips 3 which are connected in the manner described above to the steel strip 2. This strip has the same dimensions as the strips of aluminum. steel 2 already described-The steel strip 2 is covered by the two aluminum layers or by the aluminum sheets 3 so that its two electrical connection surfaces 4ne are not covered on their two faces. The two layers

  3 therefore only extend beyond

  above the middle part of the steel strip 2.

  The thickness of the two layers or strips of aluminum is

  also between 0.05 and 0.4 mm.

  The element connecting member shown in Figure 6 is formed of two steel legs 2. The 11.

  length of the two steel legs is equal to about 15 mm.

  In the case where the conditions so require, the steel legs

  can also be made with a larger size than

  re or lower. The thickness of the two steel lugs 2 corresponds to the thickness of the steel strip 2, which is used for the realization of the connecting member between elements shown in FIGS. 1 to 5. The two legs of 2 are arranged facing each other, while leaving a spacer space, so that

  that their longitudinal axes are located in a plane.

  The spacing between the two steel legs is determined by the desired length of the connecting member between elements. In the preferred embodiment, this length is about 50 mm. The two steel legs are interconnected by means of an aluminum strip 3. The latter is applied at both ends to each of the two steel lugs 2. The aluminum strip 3 is connected to in an electrically conductive manner and by a force connection to both legs

  of steel, using one of the above-mentioned procedures

  dermment. The length of the aluminum band is determined by the spacing between the two steel legs 2. This

  spacing is preferably between 0.5 and 1 mm.

  The connection member between elements 1 represents

  7 is formed by three steel strips 2.

  Each of these steel strips is covered on both

  aluminum layers 3. These layers of aluminum

  Nium 3 can also be replaced by aluminum strips 3 laminated on both sides of the strips. The steel strips 2 thus covered are stacked one on the other and are interconnected by a force link. To realize the connecting member between elements 1, it is also possible to

  cover with aluminum or to coat with a strip of aluminum

  each of the steel strips only on one of

  his faces. The steel strips 2 are preferably stacked

  placed on each other in such a way that the face covered with a strip of steel is respectively adjacent to the

  uncoated side of the adjoining steel strip.

  Figure 8 shows an element connecting member 1, which is made in the manner of a metal fabric. The latter comprises two and preferably several intertwined steel wires. These son are provided with an aluminum coating (here not shown). Both ends of the metal fabric are

  connected respectively to a steel bushing 4. These bushings

  make them the electrical connection surfaces

  of the connection element between elements.

  FIG. 9 diagrammatically shows two electrochemical accumulator elements 6. These two accumulator elements form part of a battery (not shown here) and are connected in parallel. The metal housings of the two accumulator elements 6 serve as first current collection members and are interconnected via a member 1 for connection between elements. This element 1 for connection between elements is permanently connected to the two metal housings of the storage elements 6. It is produced in accordance with the embodiment shown in FIG. 6 and comprises two steel lugs 2, each of which is connected to a housing. of an accumulator element 6. The two steel legs 2 are interconnected electrically by means of a band

  3. The two accumulators 6 constitute

  each kill another current collection member 7.

  These two current collection members 7 protrude inside the respective storage elements, in particular in the space of the reagent product, bounded by the solid electrolyte:

  a few millimeters above the accumulators 6.

  They are also interconnected via a member 1 connecting elements. This element connecting member is made according to the embodiment shown in Figure 2. It comprises a steel strip 2 which is covered entirely on a

  face by an aluminum layer 3 or an aluminum strip 3.

  On its connection surfaces 4 it is equipped with eyelets (here not shown). Through each eyelet 5, one

  can insert a screw 8 and screw it into the organ res-

  current drawing phase 7.

  The element 1 connecting elements according to the invention is not only limited to the forms of

  embodiment of Figures 1 to 8. On the contrary, it can take

  also embodiments which have a larger number of steel strips and aluminum layers or in which the steel strips and

  aluminum are only available in places.

Claims (21)

  1. Electrochemical accumulator element   killed on the basis of an alkali metal and a chalcogen, comprising at least one anode space for receiving the anolyte and a cathode space for receiving the catholyte and which are separated from each other by a wall formed of a solid and conductive electrolyte for the alkaline ions and are at least partially limited by a   metal wall, a first neck take-off member   rant being constituted by an electrode introduced into the space of the reactant product, limited by the wall formed by the solid electrolyte, while a second current draw member is formed by the metal wall, and that each organ of current draw can be connected to at least one metal connecting member between elements   to connect in an electrically conductive   the accumulator element to at least one other accumula-   characterized in that the metal member (1) for connection between elements is made, at least in places, by two or more electrically conductive flat layers (2 and 3) and arranged at least partially above one another and wherein at least a first layer has a low junction strength and a defined mechanical stability and at least a second layer is resistant to oxidation   and has a low ohmic resistance, and that   electrical connection faces (4) of the con-   between elements (1) are carried out at least by one of the two layers (2, 3).   Accumulator element according to Claim 1, characterized in that the first layer (2) is produced in steel.   3. Accumulator element according to any one   claims 1 and 2. characterized in that the se-   layer (3) is made of aluminum.   4. Accumulator element according to any one   Claims 1 to 3, characterized in that the member (1)   connection between elements is made in the form of a strip.   5. Accumulator element according to any one   Claims 1 to 4, characterized in that the second   layer (3) is an aluminum layer deposited by   plasma concentration on the first layer (2).   6. Accumulator element according to any one   Claims 1 to 4, characterized in that the second   layer (3) is formed by an aluminum strip.   7. Accumulator element according to any one   Claims 1 to 4, characterized in that the two   layers (2 and 3) are connected to each other by cold plating. 8. Accumulator element according to any one   Claims 1 to 4, characterized in that the two   layers (2 and 3) are interconnected by hot.   9. Accumulator element according to any one   Claims 1 to 5, characterized in that the second   layer (3) is deposited by immersion aluminizing the first layer (2).   10. Accumulator element according to any one   Claims 1 to 4, characterized in that the two   layers (2 and 3) are welded to each other.   11. Accumulator element according to any one   Claims 1 to 10, characterized in that the organ   (1) of connection between elements is constituted by a ban-   of steel (2) of which one face is provided with a layer   aluminum or an aluminum strip (3).   12. Accumulator element according to any one   claims 1 to 10, characterized in that the organism   The inter-element connection (1) is formed by a steel strip (2) provided on both sides with a layer   aluminum or an aluminum strip (3).   13. Battery cell according to any one of   Claims 1 to 10, characterized in that the layer   aluminum or the aluminum strip (3) affixed to one side is arranged only in the central part of the strip of steel (2).   14. Accumulator element according to any one   claims 1 to 10, characterized in that the   made of aluminum or aluminum strips (3), affixed on both sides, are placed only in the central of the steel strip (2).   15. Accumulator element according to any one   Claims 1 to 14, characterized in that the sur-   electrical connection faces (4) are arranged on both ends of the member (1) connecting elements. 16. Accumulator element according to any one   Claims 1 to 15, characterized in that the   electrical connection surfaces (4) of the connection member between elements are respectively provided with   minus one eyelet (5) allowing the screwing.   17. Accumulator element according to any one   claims 13 and 14, characterized in that the   electrical connecting surfaces (4) of the connecting member between elements are constituted by the two ends of the steel strip (2) with or without a coating.   18. The accumulator element according to claim 1, characterized in that the member (1) for connection between elements is constituted by at least two steel lugs (2).   interconnected by means of a strip of aluminum   minium (3) and constituting the connecting surfaces electric (4).   19. Battery element according to claim 1, characterized in that the connecting member (1) between   elements is constituted by at least two steel strips (2).   arranged one above the other and which are each yellow on one or both sides of an aluminum layer (3) and are interconnected.   20. Accumulator element according to claim 1, characterized in that the connecting member (1) between   elements is constituted by a metal fabric (2).   21. Accumulator element according to claim 20, characterized in that the metal fabric (2) is constituted by at least two aluminum-coated steel wires, the two ends of which are respectively connected to   steel bushings constituting the connecting surfaces   (4) of the member (1) connecting elements.