FR2620869A1 - ELECTROCHEMICAL ACCUMULATOR WITH RECHARGEABLE POWER - Google Patents

Abstract

The invention relates to an electrochemical accumulator 10 having a housing 12 divided by a separator 20 into two electrode compartments for an anode substance 40 and a cathode substance 38 and an electrolyte 36. According to the invention, the separator 20 is sealed to compression to housing 12 to separate the electrode compartments from each other, by means of compression gaskets 44, 48. Each compression seal 44, 48 comprises a tightly wound coil metal spring and a sealing strip made of ductile metal which is subjected to spring pressure. The spring is radially constrained by a force sufficient to elastically compress the spring radially and sufficient to produce plastic deformation of the sealing strip. Application to the manufacture of accumulators.

Description

I o o2620869 Electrochemical Rechargeable Battery Pack

  The invention relates to an electrochemical accumulator of rechargeable power operating at high temperature. More precisely,

  it relates to such an accumulator of the type comprising a substance

  this anodic liquid and an active cathodic substance in contact

  with a liquid electrolyte, the anodic substance and the electrolytic

  the liquid being separated by a separator which is permeable to the

  anodic substance in ionic form.

  According to the invention, the subject of the invention is a battery

  electrochemical rechargeable battery operating at high tempera-

  which comprises an accumulator tank divided by a separator

  solid electrode into a pair of electrode compartments, one of which is an anode compartment which contains an anodic substance

  active and the other is a cathode compartment which

  holds an active cathodic substance and an electrolyte, said

  anode substance and said electrolyte being liquid at the temperature

  function of the accumulator, the separate separator

  the anodic substance of the electrolyte and the substance

  thodic and allowing the anode substance, in operation

  to pass from the anode compartment into the cathodic compartment

  that, conversely, in ionic form, the separator being sealed

  by compression to the tank to separate the compartments one

  on the other by at least one compression seal comprising, in

  boring, a radially elastic helical metal spring

  winding and at least one duct metal sealing strip

  the spring forming a support for each sealing strip

  and being constrained in its radial direction by a sufficient force

  to elastically compress the spring in its radial direction and sufficient to produce a plastic deformation of

each sealing strip.

  There may be two of said two-sided sealing strips

  opposite respectively of each coil spring which are de-

  formed plastically therefrom.

  Each seal may be in the form of a split ductile metal tube having a slot along its length, the spring extending inside the tube being embraced by the tube, the split tube

  forming a pair of sealing flanges on opposite faces

  of the spring forming the said sealing strips, the res-

  fate forming a radially elastic core for the split tube and the slot in the wall of the split tube facilitating the deformation thereof. One of the electrode compartments is an anode compartment,

  the other being a cathode compartment. Typically, the substance

  this active anodic comprises a molten alkali metal such as

  dium, the liquid electrolyte is also melted and comprising for example an aluminum halide and alkali metal. In this case, a movement of ions of anodic substance such as

  that sodium ions through the separator from the compartment

  anode to the cathode compartment during the discharge

  and, during charging, a movement of these ions in the direction

  milk through the separator, with volumes of gas being

  above the liquid levels in the compartments.

  In a particular embodiment of the accumulator, the

  node is in molten sodium and the cathode is in the form of a matrix

  this permeable to the electrolyte and electronically conductive, im-

  charged with liquid electrolyte, the liquid electrolyte being an electrolyte

  molten salt trolyte of an aluminum and sodium halide (eg chloride) and the separator being a solid conductor of sodium ions such as beta-alumina or the body known as

  "nasicon", or a micromolecular sieve containing adsorbed sodium

  or absorbed in it. In this embodiment, the matrix may be constituted by at least one member of the group comprising

  Fe, Ni, Co, Cr, and Mn and compounds of one or more of these

  transition rate with at least one non-metal of the group comprising

  carbon, silicon, boron, nitrogen and phosphorus.

  Regarding the solid conductor of sodium ions or sieves

  micromolecular, it separates the anode compartment from the

  in such a way that any anodic active substance such as sodium passing from the anode to the electrolyte, or vice versa, must pass through the internal crystalline structure of the

  solid conductor or cross the microporous interior of the half sieve

  cromolecular, as the case may be, in atomic form through

  towards the interface between the anode and the separator and going under

  ionic form through the interface between the electrolyte and the sepa-

  tor. The term "micromolecular sieve" is understood to mean a molecular sieve having intercommunicating cavities and / or channels inside it and, in its surface, windows and / or pores leading to said cavities and

  channels, said windows, pores, cavities and / or channels having a di-

  not more than 50 Angstrom and, preferably, less than

  Angstrbm. Such sieves include micromolecular sieves

  minerals such as tectosilicates, examples of which are

zeolites 13X, 3A and 4A.

  According to a particular embodiment of the invention, the

  The spacer may be in the form of a separator tube which is closed at one end and open to the other, the accumulator chamber comprising a cylindrical housing arranged concentrically around and separate from the separator tube, said seal compression

  between the separator tube and the tank being disposed at the end or-

  green of the separator tube via an insulating ring

  in an electronically insulating material, the open end of the

  be separator being welded to the glass hermetically to the insulating ring

  lante and the compression seal being disposed between the insulating ring

  and the housing, and the open end of the separator tube being provided with a sealed closure forming part of the vessel,

  in such a way that the separator tube divides the inside of the cu-

  in said pair of electrode compartments, one of which is inside the separator tube and the other of which is between the tube

separator and the housing.

  The accumulator may comprise two of said compression seals, namely said compression seal between the insulating ring and the casing and a compression seal between the insulating ring and the sealed closure of the separator tube, the insulating ring having a pair of end faces facing each other and axially opposed against which the compression seals abut, and the seals

  being constrained by a force acting in said axial direction

the.

  Each compression seal may have an annular shape of such

  the way it functions as an O-ring seal, the ductile metal of the seal having the shape of a toroidal coil

  endless hollow in the form of a ring, the coil spring extends

  along the entire length of the inside of the coil to-

  roïdale. As indicated above, the toroidal coil may have

  a slot along its length to make it easier to deform

  plastics, and this may be on its outer periphery.

  Lower in relation to its polar axis.

  Keeping in mind the foregoing, a form of

  The preferred embodiment of the accumulator may be that in which the anode material is sodium housed between the separator tube and

  the case, the active cathode material being, in the state of charge,

  Complete geometry of the accumulator, MC12 wherein M is a transition metal selected from the group consisting of Fe, Ni, Co, Cr and Mn

  or mixtures thereof, and being housed within the separate tube

  at the same time as the electrolyte, which is, in the complete state of charge of the accumulator, an aluminum-sodium chloride according to the formula NaAlCl 4, in which the molar ratio Na: Al

  is not less than 1, the active cathodic material being

  in a permeable electronically conductive porous matrix

  electrolyte impregnated with the electrolyte, the isolating ring

  being alpha-alumina and the separator tube being in beta "-alu-

mine.

  The metal of the seals must be inert in the environment.

  accumulator of the accumulator compartment that it

  the. The metal must not react chemically or electrochemically

  during operation of the battery with the

  electrode or the electrolyte of the accu-

he is sealed.

  Thus, when M is selected from Fe, Ni or mixtures thereof, each compression joint may be nickel or a nickel alloy which is inert in the environment of the accumulator

  vis-à-vis the contents of the electrode compartments.

  The molar proportion of the alkali metal cations in the electro-

  lyte is, preferably, as indicated above, not inferior to

  the molar proportion of aluminum cations in the electrolyte

  at all stages of charging the accumulator. When electricity

  trolyte is a sodium aluminum chloride, this can be

  by charging the cathode compartment with enough chlorine

  sodium chloride so that the solid sodium chloride is present and in contact with the liquid electrolyte during all stages of charging. This solid sodium chloride must be present at least at all stages of discharge other than the complete state of charge

of the accumulator.

  The invention also extends to an accumulator tank for a

  electrochemical power accumulator which is divided by a

  solid parator into a pair of electrode compartments, one of which is an anode compartment to contain a substance

  active anode and the other of which is a cathode compartment

  contain an active cathodic substance and an electrolyte,

  the separator separating the anode compartment from the compartment

  and being able, in operation, to allow a

  anodic substance from the anode compartment to the compartment

  cathodic and vice versa, in ionic form, the separator

  being sealed to the tank to separate the compartments

  of one another, by at least one compression seal com-

  in combination, an elastic metal coil spring

  radially with a tight winding, and at least one sealing strip

  made of a ductile metal, the support spring for each

  sealing and can be forced in its radial direction

  by a force sufficient to elastically compress the

  out in its radial direction and sufficient to cause a deform-

  plastic molding of each sealing strip.

  The invention also extends in an electrochemical accumulator

  rechargeable power operated at high temperature

  taking a storage tank divided by a solid separator

  in a pair of electrode compartments one of which is a comparator

  anodic substance containing an active anodic substance

  the other is a cathode compartment containing a substance

  active ingredient and an electrolyte, said anode substance and the

  said electrolyte being liquid at the operating temperature of the accumulator, the separator separating the anode substance from

  the electrolyte and the cathodic substance and

  the anodic substance to pass from the anode compartment

  cathodic compartment and conversely, in ionic form, to a process for sealing the separator to the tank in order to separate the compartments from each other which consists of accommodating, between the

  separator and the vessel, a compression seal comprising, in

  boring, a radially elastic metal coil spring with a tight winding, and at least one sealing strip made of a metal

  ductile, the spring and each band being housed side by side of such

  the way the spring forms a support for each band, and

  push the separator towards the tank to tighten the spring and each

  that band between them with sufficient force to constrain the

  spring to a state of elastic radial compression and to produce

  re plastic deformation of each sealing strip.

  The invention will now be described, by way of example, in

  in the accompanying diagrammatic drawings in which: Figure 1 is a sectional side elevational view of

  of the tank of an electrochemical accumulator recharged

  operating at high temperature in accordance with the

  the invention; FIG. 2 is a side elevational view of

  cutaway of the accumulator seals

  of Figure 1; FIG. 3 is a view similar to that

  FIG. 1 of another embodiment of a

  accumulator according to the invention; and FIGS.

  4C represent detail views of variants of the arrangement

  sealant of Figure 3.

  In FIG. 1 of the drawings, the storage tank carries the reference

  this general 10 and is shown broken halfway to its length

  typically having an outer diameter of about 50-60mm and a length of about 30-60cm. The tank shown is for an accumulator having anode material consisting of molten sodium, a liquid electrolyte formed of aluminum-sodium chloride and a

  cathodic substance which, in its state of charge, comprises a

  active porous trice permeable to the electrolyte and electrically conductive

  which contains Fe C12, NI Cla or FeC12 / NiCl2 dispersively

  in and saturated with said electrolyte, the matrix being sufficient

  of finely divided NaCl dispersed in it to ensure that,

  in all stages of charge of the cathodic substance, elec-

  trolyte is an equimolar mixture of NaCl and AlCl3, i.e.

  stoichiometrically precisely NaAlCl4.

  The storage tank 10 comprises an outer mild steel casing 12 having a base 13 for holding it in its vertical operating position on a horizontal support surface (not shown). The casing 12 comprises a cylindrical box 12.1 and

  a seat 14 of mild steel casing welded together in 15 at the top.

  puts the box 12.1. The seat 14 is closed by an upper housing

  ring or annular cap 16 made of stainless steel or aluminum

  On top. The cap 16 has a battery terminal 18 in

  stainless steel or aluminum, as appropriate, welded on. A tu-

  The open-ended beta-alumina separator 20 is housed in

  centric inside the housing 12, the upper end or-

  green of the tube 20 being welded to the glass to a ring 22 in alpha-aluminum.

  mine, this ring 22 resting by a sliding slot in 24

  against an inner curved surface provided for this purpose on the

  14. The tube 20 is closed at its lower end.

  The tube 20 is closed by a closure member 26 made of mild steel.

  This closing member 26 clamps the ring 22 with alpha-alumina con-

  be a shoulder 28 on the seat 14 and the closure member 26

  is in turn tightened in position by the cap 16. The iron organ

  setting 26 has a central through passage 30 in which

  is welded a terminal made of stainless steel or aluminum. The extremities

  lower end of terminal 32 protrudes into an adjacent

  at the closed end of the tube 20 and a nickel cloth 34

  rolled tightly around its outer surface.

  The inside of the tube 20 forms a cathode compartment and is

  ply of electrolyte 36 in molten salt, a porous cathodic matrix

  38 being formed on the outer surface of the terminal 32, which

  the terminal acts as a cathode current collector, the wire 34 being embedded in the die 38. The space between the casing 12 and the tube 20 forms an anode compartment and contains sodium

  40. Gas volumes 41, 42 (not to scale) are

  above the electrolyte 36 and sodium 40 respectively.

  is lying. The member 26 is sealed to the ring 22 by an O-ring 44

  nickel housed in a circumferential groove 46 in the underside

  member 26, and the ring 22 is in turn sealed at

  seat 14 by a nickel ring 48 housed in a sheet of paper.

  defined by an annular shoulder 50 in the seat 14 adja-

  The cap 16 is electronically isolated from the member 26 by an annular disc 52 made of mica and the member 26

  is electronically isolated from the seat 14 by a ring 54 of mica.

  The nickel ring 44 is housed in the groove 46 on the

  26 through an annular disk 56 in oil

  (graphite) and on the ring 22 via a

  than annular 58 aluminum, the O-ring 48 being housed in

  similar way on the shoulder 50 via a

  ring 60 in graphitized oil and on ring 22 through

  median of an annular disc 62 aluminum. The discs are

  graphite and aluminum are optional and can, if it is

desire, to be omitted.

  The tank 10 is adapted to an accumulator of the cathode type between

  in such a way that the porous cathodic matrix 38 is

  on the outer surface of the terminal 32, the wire 34 being

  robed in this matrix and the fabric 34 and the terminal 32 acting as a cathode current collector. The box 12 acts to his

  tower as anodic current collector.

  In Figure 2, the seals 44, 48 are shown in more detail.

  They are made of nickel and are essentially identical, each

  taking a nickel-plated outer tube 64 made of nickel

  toroidal groove and having a longitudinal slot 66 along its outer periphery. A nickel-tight helical coil spring 68 is housed within the tube 64 and extends along its length. The tube 64 forms a pair of ductile flanges 70,

  72 through which the point leans against the organization

  No. 26 and the ring 22 (seal 44) and against the ring 22 and the seat 14 (seal 48). In practice, it has been found that nickel gaskets of this type available under the trademark "Helicoflex Type HN" from the company Vakumet Products (Proprietary) limited, in Africa

South are suitable for this purpose.

  Referring to FIG. 3, the accumulator shown is similar to

  to the accumulator of Figure 1 in many respects and,

  unless otherwise indicated, the same parts in Figure 3 are de-

  signed by the same reference numbers as in Figure 1. It

  However, there are a number of differences in

  the accumulators of Figures 1 and 3 as explained below.

  So, instead of sitting directly against seat 14 of

  tier, as shown in 24 in Figure 1, the alumina ring 22 rests against the seat 14 via an extension

  towards the bottom of the insulating ring 54. The closing member 26 serves

  the ring 22 down, not against a shoulder 28 like

  shown in Figure 1, but against the shoulder 50 through

  median of the gasket 48, the oil disc 60 graphited between the gasket 48 and the shoulder 50 of FIG. 1 being omitted in FIG.

  Terminal 32 in turn is simply soldered to the top of the body.

  closing 26 and does not protrude into the tube 20.

  milking, a filling tube 74 passes down through the or-

  closure 26 to which it is welded, and has a closure

  re able to be sealed (not shown). A nickel current busbar 76, welded to the tube 74 at 78, passes to the

  down in a central position in the tube 20 to a position

* adjacent to the closed end of the tube 20. The canvas 34 is omitted

  se and; in its place, the matrix 38 has a lattice of nickel 80 enro-

  gaped in. The lattice 80 is extended through the volume of the material

  trice and acts as a cathodic current collector, being in con-

  with the bar 76. An annular wick casing 82 mounted

  venably is arranged around the tube 20, very little

  it, to distribute by capillary the cathodic material in so-

  melted dium on the outer surface of the tube 20. The anodized space

  that between the housing 82 and the tube 20 is optionally filled with a suitable porous capillary material (not shown) for

  to help the capillary distribution of sodium on the outer S-u'pcó

the tube 20.

  The molten salt electrolyte and sodium (36 and 40 in Figure 1) are not shown in Figure 3.

  The groove 46 of FIG. 1 is replaced by an annular shoulder.

  84 formed by a rabbet in the member 26, this leaflet

  re receiving the seal 44 in abutment with the shoulder 84. The disc

  56 graphitized oil of Figure 1 is omitted and the seal 44 repo

  directly against the shoulder 84. The seal 58, instead of being

  aluminum as in Figure 1, is in graphitized oil at the

figure 3.

  An advantage of the construction of the accumulator represented in

  Figure 3 is its ease of assembly. The seat 14 of the housing

  holding the mica ring 54 is welded at 15 to the box 12.1 of the box.

  tier to which the base 13 and wick box 82 have been

  dice; seal 48, aluminum disc or seal 62 and ring

  22 in alpha-alumina (to which the tube 20 was previously subjected

  by glass) are introduced in turn in position, followed by the disk or gasket 58 in graphitized oil and the closure member 26 (to which the terminal 32 and the tube 74 have been previously welded with the bar 76 and its lattice previously connected to the tube 74). The disk 52 mica and the cap 16 are then placed in position in turn. The crown cap 16 is then loaded axially inwards (downwards in FIG.

  sufficient force to give the springs joints 44, 48 the

  appropriate elastic compression, and with sufficient force

  te to produce a creep of their flanges 70, 72 of ductile metal

  the (Figure 2). The crown cap 16 (to which the terminal 18 has been previously welded) is finally welded to 86, with the

  joints 44, 48 under compression, seat 14 of the housing.

  To charge the accumulator, it is possible to install the vacuum in the space

  this anode between the housing 12 and the tube 20 via a suitable opening (not shown) which can be closed through the housing 12, and a suitable mixture of iron powder,

  of sodium chloride powder and aluminum chloride powder

  nium-sodium can be loaded inside tube 20 through

median of the tube 74.

  The accumulator can be brought to its operating temperature

  to solder the aluminum-sodium chloride powder to form

  an electrolyte and can be charged, the iron powder reacts

  with sodium chloride to form FeCl2 and sodium

  in ionic form passing through the tube 20 to the anode compartment

  between the tube 20 and the housing 12, to form the material

  anodic consisting of molten sodium. A proper starting mix

  ble is loaded into the tube 20 so that after several cycles

  charge / discharge, the iron porous material 38 is automatically formed

  and around the bar 76 and lattice 80, impregnated with the molten liquid electrolyte and in the presence of a small amount of excess sodium chloride in all stages of charging the accumulator. It will be noted in particular that the seals 44, 48 are chosen and

  are compressed during assembly so that, at all times,

  temperatures at which the accumulator is expected to be expo-

  especially from room temperature to room temperature.

  re operation of the accumulator, the coil springs 68 are elastically compressed and not plastically deformed, and

  so that the flanges 70 (Figure 2) are deformed plastic-

  is lying. in this way effective effective sealing is achieved

  nude and, in the tests carried out on accumula-

  prototypes, as shown in Figure 3, it was

  leaks at seals 44, 48 at a lower

less than 1%.

  Other benefits include low cost seals that are commercially available and easy automatic alignment

  of the tube 20 centrally in the housing 12.

  Referring now to FIGS. 4A-4C, there are shown

  variants of the sealing assembly of Figure 3 and, except

  contrary cation, the same reference numerals are used for the same parts in Figures 4A to 4C as those used in the

  FIG. 4A to 4C shows a corresponding detail of

  in the upper right corner of Figure 3 and, in each case,

  the detail is generally referenced 86.

  In FIG. 4A, seal 44 is shown replaced by a seal

  88 of the lip type, spaced radially inwards and adjacent to

  cent at the outer periphery of the lower surface of the

  no closure 26 of which it is integral, and extending circum-

  roughly along this periphery. The lip of this seal seals axially down against the turned surface

  upwards axially of the ring 22 alpha-alumina by the in-

  intermediate of the gasket 58 in graphitized oil, as shown.

  In the case of Figure 4B, the seal 44 is maintained and it is instead the seal 48 which is replaced by an annular seal of the lip type, referenced 90 in this case. The lip is waterproof

  axially upwards against the axially downward facing surface

  the ring 22, via the annular disc 62

aluminum, as shown. Finally, in FIG. 4C, the two seals 44, 48 are replaced

  respectively by the seals 88 and 90 of the type respectively represented

  4A and 4B. In FIG. 4C, a seal 92 of the same type as the seals 44 and 48 and having the construction shown in FIG. 2 is provided between the upper surface turned towards

  the top axially of the closure member 26 and the lower surface

  the axially downward position of the disk.52 in mica, extends

  circumferentially along their outer peripheries

  radially inward and adjacent to the said

riphéries.

Claims (10)

claims   1. Rechargeable electrochemical accumulator 10   at a high temperature which comprises a storage tank (12,13,16) divided by a solid separator (20) into a pair of electrode compartments, one of which is an anode compartment which contains an active anode substance ( 40) and the other   is a cathode compartment that contains a cathodic substance   active (38) and an electrolyte (36), said anodic substance   and said electrolyte being liquid at the operating temperature   of the accumulator, characterized in that the separator separates the anodic substance   electrolyte and cathodic substance and allows the subsystem to   anode, in operation, to pass from the   in the cathodic compartment and vice versa, in the form of io-   the separator being compression-sealed to the vessel to separate the compartments from each other by at least one seal   compression (44, 48) comprising, in combination, a metal spring   radially elastic helical coil (68) with a tight winding and   at least one sealing strip (70, 72) made of ductile metal, the   fate forming a support for each sealing strip and being constrained in its radial direction by a force sufficient to resiliently compress the spring in its radial direction and   sufficient to produce a plastic deformation of each sealing.   2. Accumulator according to claim 1, characterized in that there are two of said sealing strips (70,   72) on two opposite sides respectively of each helical spring   coïdal that feels plastically deformed by it.   3. Accumulator according to claim 2, characterized in that each seal has the form of a split tube (643 of ductile metal provided with a slot (66) along its length, the spring extending inside split tube being hugged   by the latter, the split tube forming a pair of flanges of   (70, 72) on opposite sides of the spring which form the   said sealing strips, the spring forming a core (68) elast.-   radially for the split tube and the slot in the wall of the tube.   be cracked facilitating the deformation of it.   4. Accumulator according to one of claims 1 to 3,   characterized in that the separator is in the form of a separate tube   which is closed at one end and open to the other, the   storage tank comprising a cylindrical housing (12)   se concentric around and separated from the separator tube,   said compression seal (48) between the separator tube and the housing   tier being disposed at the open end of the separator tube through an insulating ring (22) made of an insulating material   electronically, the open end of the separator tube being   hermetically sealed glass to the insulating ring and the gasket   pressure being disposed between the insulating ring and the vessel, and the   open end of the separator tube being provided with a closure   16) forming part of the tank, so that the   The separator divides the interior of the vessel into said pair of com-   electrode compartments, one of which is the inside of the separate tube   the other is between the separator tube and the housing.   5. Accumulator according to claim 4,   characterized in that it comprises two of said compression joints   sion (44, 48), namely said compression seal (48) between the insulating pad and the casing and a compression seal (44) between the insulating ring and the sealed closure of the separator tube, the   insulating ring having a pair of terminal faces   this and opposed axially against which stop the joints of   compression, and the joints being constrained by a force in said axial direction.   6. Accumulator according to one of claims 4 and 5,   characterized in that each compression seal has an annular shape   nular in such a way that it functions as an O-ring   sealing, the ductile metal tube of the joint having the shape of a   endless hollow toroidal coil (64) in the shape of a ring, the resistor   helical fate extending along the entire length of the of the toroidal coil.   7. Accumulator according to one of claims 4 to 6,   characterized in that the anode material is sodium (40)   ge between the separator tube and the housing, the active cathode material being, in the state of complete charge of the accumulator, MC12   wherein M is a transition metal selected from the group   taking Fe, Ni, Co, Cr and Mn or mixtures thereof, and being   housed inside the separator tube at the same time as the electro-   lyte, which is, in the complete charge state of the accumulator, an aluminum-sodium chloride according to the formula NaAlCl 4, in which   the Na: Al molar ratio is not less than 1, the material   the active thodic acid being dispersed in a porous matrix (38)   electrically permeable conductive tread impregnated with   the electrolyte, the insulating ring being in alpha-alumina and the   be separator being beta-alumina.   8. Accumulator according to claim 7, characterized in that M is selected from Fe, Ni or mixtures of   these, each compression seal is made of nickel or an alloy   nickel which is inert in the environment of the accumula-   to the content of the electrode compartments.   9. Tank (12, 13, 16) of accumulator for an electronic accumulator   power plant, said vessel being divided by a separator   (20) into a pair of electrode compartments of which   one is an anode compartment containing an anodyne substance   active and the other of which is a cathodic compartment containing   an active cathode substance and an electrolyte,   characterized in that the separator separates the anodic compartment   than the cathode compartment and is capable, in operation, of allowing an anode substance to pass from the compartment   anodic to the cathodic compartment and vice versa, in the form of   the separator being sealed to the tank for separation.   the compartments of each other, by at least one seal of   compression (44, 48) comprising, in combination, a coil spring   radially resilient metal coil (68) with a tight winding, and at least one sealing strip (70, 72) of a ductile metal,   the support spring for each sealing strip and   being forced in its radial direction by a sufficient force   to resiliently compress the spring in its radial direction   and sufficient to cause plastic deformation of each than sealing tape.   10. In an electrochemical accumulator of recharging power   ble (10) operating at a high temperature comprising a tank of   accumulator (12, 13, 16) divided by a solid separator (20) into   a pair of electrode compartments, one of which is a compartment   anode containing an active anodic substance (40) and whose   the other is a cathode compartment containing a substance   active ingredient (38) and an electrolyte (36), said   said electrolyte being liquid at the operating temperature   of the accumulator, the separator separating the substance   anode of the electrolyte and the cathodic substance and   in operation, the anodic substance to pass from the   anodic portion to the cathode compartment and vice versa, in ionic form, a method for sealing the separator to the tank in order to separate the compartments from one another, characterized in that it consists in accommodating, between the separator and   the vessel, a compression seal (44, 48) comprising in combination   its, a radially elastic metal coil spring (68) tightly wound, and at least one sealing strip   (70, 72) of a ductile metal, the spring and each band being   side-by-side so that the spring forms a support for each band, and push the separator towards the tank for   tighten the spring and each band between them with sufficient force   to force the spring to a state of radial compression   the elastic and to produce a plastic deformation of each sealing strip.