Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/30—Deferred-action cells
  • H01M6/36—Deferred-action cells containing electrolyte and made operational by physical means, e.g. thermal cells
  • H01M6/38—Deferred-action cells containing electrolyte and made operational by physical means, e.g. thermal cells by mechanical means

Definitions

• the invention relates to electrochemical plaice, in particular electrochemical cells of the so-called “reserve” type. It particularly relates to means for initiating such batteries.
• Electrochemical cells of the reserve type are cells intended to be put into operation after a storage period of which the duration is variable, and can range for example up to 15 years and more.
• This type of battery is widely used to supply electrical energy in ballistic missiles, for example shells, missiles, etc. . . But these batteries are also of great interest in other fields, for example that of security devices.
• Reserve type batteries provide electrical energy from the moment they are primed. Priming the battery consists in bringing together the different elements which, in a conventional manner, transform the chemical reaction into electrical energy.
• Such an electrochemical cell can comprise one or more electrochemical cells, the number of these cells being a function of the voltage to be obtained.
• each cell comprises two electrodes of opposite polarities in contact with a quantity of liquid electrolyte.
• the liquid electrolyte is kept outside the cell in a storage tank, until the moment of priming. Priming the battery consists in releasing the electrolyte.
• the present invention relates to electrochemical cells, in particular of the reserve type. It particularly relates to means for initiating such batteries, and applies equally well in the case of strong or weak accelerations, with centrifugal force or not. It allows very rapid priming while avoiding self-consumption faults and poor distribution of the electrolyte.
• the invention lends itself well to economic industrial achievements to the point that it can be applied in many fields other than those already mentioned, for example the electrical supply of safety devices, such as fire extinguishers, beacons, etc. . . .
• an electrochemical cell comprising at least one cell, the rellule comprising two opposite polarized electrodes and an electrolyte space containing an electrolyte, is characterized in that it furthermore comprises means for, on the one hand maintaining the electrodes outside the cell during a storage period of the battery, and on the other hand place these electrodes in the cell to prime the battery.
• This solution is particularly advantageous in that it makes it possible to store the electrolyte in the cell itself, at the position of use, so that the placement of the electrode causes the battery to operate immediately.
• the distribution of the electrolyte in the cells is always correct since it is carried out during the manufacture of the cell.
• FIG. 1 shows a battery according to the invention
• FIG. 2 is a top view of the cell of the invention showing a distribution of several cells with their electrodes.
• Figure 1 shows schematically, by way of example l "- ** without limitation, an electrochemical cell 1 according to the invention.
• Battery 1 is of the reserve type. It comprises an enclosure 2 which, in the nonlimiting example described, has a circular section (represented by its diameter dl), the plane of this section being perpendicular to that of FIG. 1. 0 Several electrochemical cells are arranged around a longitudinal axis 5 of the enclosure, of which only two cells C2, CIO are shown in FIG. 1.
• Figure 2 is a top view of the stack 1, view which is symbolized in Figure 1 by an arrow 4, and which 5 shows the stack 1 according to its section.
• 14 consecutive electrochemical cells C1 to C14 are distributed around the longitudinal axis 5 at a pitch p; the longitudinal axis 5 being perpendicular to the plane of Figure 2, it appears on 0 the latter as a point.
• these cells can be arranged differently and be in a different number, larger or more sfaible can go up to a single cell.
• Each cell C1 to C14 includes two electrodes E -, E + of opposite polarities, arranged on either side of a space called “electrolytic space” 7 containing an electrolyte 8.
• the electrochemical cells C1 to CM are connected in series and add the voltages they produce, so that the total electromotive force is available between two outputs "+", "-", one of which is the positive polarity delivered by an electrode E +, from the first cell Cl, and the other "-" is the negative polarity delivered by the electrode E- of the last
• the electrodes E-, E + are constituted by bipolar plates, that is to say that they are carried by separating plates PI to P15, on the two large opposite faces of the latter: the plaques
• separators PI to P15 are made of a conductive material one side of which is covered, for example, with lead to form a negative electrode E-, and the other side of which is covered, for example, with lead dioxide (Pb0_) to form a positive electrode E + .
• the third separator plate P3 which separates the second and third electrochemical cells C2 and C3, carries on one face the negative electrode E- of the second cell C2 and carries its opposite face the electrode E + of the third cell C3.
• the electrolytic space 7 is determined in each cell C1 to C4 between the two electrodes E +, E- and between 3 insulating walls: the first called peripheral wall 10 is on the side of the enclosure 2; the second located opposite the first is called central wall 11, it is constituted by example by a crown of insulating material 13 centered on the longitudinal axis 5; the third insulating wall being formed by the insulating bottom 21 of the cell.
• the peripheral and central walls 10, 11 are separated by a distance D1 called separation which extends parallel to the rays (not shown) of the enclosure 2.
• the separating plates PI to P15 when the stack 1 is in operation, have a length L1 parallel to the distance Dl of separation and greater than the latter, so that each of the lateral edges 16, 17 separator plates PI to P15 protrude and are inserted into the peripheral and central insulating walls 10, 11. These lateral edges 16, 17 are thus enclosed in the walls 10, 11 and protected from any contact with the electrolyte 8, in order to '' avoid the phenomenon of self-consumption.
• the latter particularly represents, on the one hand, the second cell C2 in a left part of the figure located in a box marked 25; and it particularly represents the tenth cell C10 in a second box marked 26.
• box 25 is to illustrate the storage position of the battery, that is to say its state is not primed and therefore when it is not working.
• Box 26 is to illustrate the primed position when the battery is put into operation.
• the electrodes E +, E- are held outside the cells C1 to C14.
• the third separating plate P3 carries on its visible face a negative electrode E- intended for the second cell C2, and carries on the other face a positive electrode E + intended for the third cell C3.
• the priming of the cell 1 is obtained by the installation of the different electrodes E +, E- in the different cells C1 to C14.
• all the separating plates PI to P15 are moved from a high position (shown in box 25), to a low position
• P15 is illustrated in Box 26 in which it is seen that a positive electrode E +, forming the visible face of the tenth separator plate P10, is placed inside the tenth CIO cell.
• separating plate P10 has a length L1 greater than the separation distance Dl, so that its lateral edges 16 and 17 are engaged in the insulating walls 10, 11. Furthermore the separating plates have a height Hl greater than the depth H2 of the electrolytic space 7, of
• each cell C1 to C14 contains the quantity of electrolyte necessary for its operation, and the electrodes E +, E- are kept apart from the electrolytic block.
• Priming consists in placing the electrodes E +, E- in the electrolytic block, in contact with the electrolyte. This is obtained by a relative movement between the electrolytic block and the PI P15 separator plates, and as described above, the dimensions of the latter are such that, as they are inserted into a cell, they penetrate the peripheral walls and central 10, 11 in which their lateral edges 16, 17 are embedded and isolated from the electrolyte, just as their lower edge 18 is pressed into the bottom 21; this arrangement makes it possible to avoid the phenomenon of self-consumption which occurs when the edge of a bipolar blade is immersed in the electrolyte.
• the electrically insulating material in which the walls 10, 11 and the bottom 21 are made must have a structure suitable for being allowed to penetrate the edges of the plates without falling apart, and for maintaining a seal around these edges.
• Materials having the required qualities are for example elastometers, or gels of the silicone type.
• the electrolyte can be in liquid form or preferably in solid form, that is to say in the form of a gel.
• electrolytic gel can be obtained in itself simple, by adding gelling agents to the electrolyte, for example based on colloidal silica or the like.
• the electrolytic gel can for example be based on colloidal silica, plus fluoboric acid and diethylene glycol.
• the separating plates PI to P15 are maintained at positions defined around the longitudinal axis 5, with predetermined spacings between them which correspond to the pitch p of the cells C1 to C14.
• the zone containing the electrolyte that is to say the succession of electrolytic spaces 7 can be covered with a film or seal 32 waterproof, for example in thermo-welded plastic.
• the cover 32 also provides mechanical maintenance of the electrolytic gel.
• the cover 32 is necessary to keep the electrolyte in its housing which constitutes the succession of electrolytic spaces 8.
• the cover 32 is perforated by the lower edges 18 of the separating plates PI to P15, during the 'sinking of the latter into the; * * cells.
• the inner edge 18 and possibly the edges 16, 17 of these plates can be made sharp, by example by giving them a triangular shape (not shown).
• the movement which must lead to the insertion of the electrodes E +, E- in the cells C1 to C14 can be obtained by a displacement of the separating plates PI to P15 and / or by a displacement of the electrolytic block 30.
• the separating plates PI to P15 are overmolded in a plastic part
• the plastic part 38 extends above the succession of cells C1 to C3, and it carries the separating plates PI to P15 with which it constitutes a possibly displaceable block called "electrode block" 35.
• the separating plates PI to P15 are thus fixed to each other, and maintained with a spacing between them which corresponds to the pitch p according to which the cells C1 to C14 are arranged.
• the displacement of the electrode block 35 is symbolized by an arrow 29; it must be carried out over a distance d2 which is that necessary to transport the separating plates PI to P15 from the storage position (represented in box 25), to the primed position where they are in the cells, as shown in box 26.
• the electrode block 35 can slide for example along a shaft 44 disposed along the longitudinal axis 5.
• the electrode block 35 can be guided in different ways, it can be guided for example using a rib 70 on the shaft 44.
• the displacement of the electrode block 35 from the storage position to the primed position can be accomplished using various means which are known per se, in particular depending on the application of the battery 1.
• the block of electrodes 35 can behave like a counterweight whose inertia at the moment of the departure of the shell, causes the displacement and consequently the insertion of the electrodes in the
• the electrode block 35 acts like a piston and slides on the central shaft 44 so as to be movable along the longitudinal axis 5, between two positions PS and PA: the
• first position PS is that which is closest to an upper wall 38 of the enclosure 2, and. it constitutes the storage position, the second position A being the primed position.
• the electrode block 35 is maintained in the storage position PS by conventional means (not shown).
• the generator 41 is arranged in the example in a space 43 formed between the electrode block 35 and the upper wall of the enclosure 2.
• the control of the gas generator 41 can be carried out in a conventional manner generally by an electrical pulse.
• the shaft 44 is equipped a non-return device.
• a non-return device Various means are known for this purpose. In the nonlimiting example described, this is accomplished using a leaf spring 71 which, during storage, is retracted into the shaft 44 itself; when the electrode block 35 is pressed, the spring 71 escapes and thus prevents a return movement of the electrode block 35.
• a priming device 40 allows the priming of the battery 1 in a large number of situations and applications: control by electric pulse, percussion or others.
• an electrochemical cell in accordance with the invention is of very particular interest in the case of mortar fire, because the placement of the electrolyte in the cells of the electrolyte and the balancing in the cells of this electrolyte does not require the presence of a centrifugal force.
• the outputs "+” and “-” of the electromotive force of battery 1 (that is to say coming from the placing in series of all cells C1 to C14) , are symbolized as being available at first ends 60, of two connecting wires FI, F2; these outputs "+” and “-” being fixed.
• the two wires FI, F2 are connected at their second end 61 respectively to the plates PI and P15, the electrical contacts being obtained for example by soldering.
• the electrodes are mobile, that is to say if the insertion of the separating plates PI to P15 between the cells C1 to C14 results from a displacement of these separating plates as explained above, it is necessary to connect the first and the last PI plate, P15 to the fixed connections of the battery, for example by a flexible wire; the wires FI, F2 then have sufficient clearance to absorb the displacement of the electrodes.
• a connection by spring leaf (not shown) in itself conventional, as described for example in US Pat. No. 4,331,848.
• the output connections are conventionally and simply carried out on the electrodes themselves.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Primary Cells (AREA)
• Secondary Cells (AREA)

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• 1991
  • 1991-09-03 FR FR9110865A patent/FR2680915A1/fr not_active Withdrawn
• 1992
  • 1992-08-28 US US08/039,421 patent/US5389461A/en not_active Expired - Fee Related
  • 1992-08-28 WO PCT/FR1992/000826 patent/WO1993005542A1/fr not_active Application Discontinuation
  • 1992-08-28 EP EP92919063A patent/EP0555461A1/de not_active Ceased
  • 1992-08-28 KR KR1019930701331A patent/KR930702792A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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