Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/24—Electrodes for alkaline accumulators
  • H01M4/26—Processes of manufacture
• • 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
  • H01M10/24—Alkaline accumulators
  • H01M10/28—Construction or manufacture
  • H01M10/281—Large cells or batteries with stacks of plate-like electrodes
  • H01M10/282—Large cells or batteries with stacks of plate-like electrodes with bipolar electrodes
• • 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
  • H01M10/04—Construction or manufacture in general
  • H01M10/0413—Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes
  • H01M10/0418—Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes with bipolar electrodes
• • 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
  • H01M10/04—Construction or manufacture in general
  • H01M10/0436—Small-sized flat cells or batteries for portable equipment
  • H01M10/044—Small-sized flat cells or batteries for portable equipment with bipolar electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/24—Electrodes for alkaline accumulators
  • H01M4/26—Processes of manufacture
  • H01M4/30—Pressing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/70—Carriers or collectors characterised by shape or form
  • H01M4/80—Porous plates, e.g. sintered carriers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
  • H01M2004/029—Bipolar electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/70—Carriers or collectors characterised by shape or form
  • H01M4/80—Porous plates, e.g. sintered carriers
  • H01M4/808—Foamed, spongy materials
• • 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
• • 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
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• the present invention relates to a bipolar electrode for an alkaline electrolyte accumulator of the type comprising a bipolar screen, electronic conductor, on the faces of which are fixed respectively a positive electrode and a negative electrode.
• a bipolar electrode for an alkaline electrolyte accumulator of the type comprising a bipolar screen, electronic conductor, on the faces of which are fixed respectively a positive electrode and a negative electrode.
• the present invention also relates to an alkaline accumulator comprising at least one bipolar electrode according to the invention and a method of manufacturing such an electrode.
• sealed bipolar alkaline accumulators implies that the architecture of the constituents is such that the phenomena of recombination of the oxygen formed at the end of charging can operate with rapid kinetics.
• an intermediate three-dimensional structure such as a foam or a sieve is arranged between the active material of the electrodes and the bipolar screen.
• connection problems mentioned above should be resolved, at the screen / intermediate structure and intermediate structure / armature of the electrodes level.
• the present invention aims to overcome in particular the drawbacks which have just been described.
• the subject of the invention is a bipolar electrode for alkaline accumulators, comprising a conductive screen, a three-dimensional collector comprising asperities, plated on each face of the conductive screen, and active material filling the collectors to respectively form the positive and negative electrodes, and at least one of the faces of the conductive screen is grooved, and the three-dimensional collectors are bonded to the conductive screen by a stable non-conductive adhesive in the presence of a strongly alkaline electrolyte and are in direct contact with the external faces of the conductive screen via the roughness of the three-dimensional collectors.
• the grooves of determined width, depth and spacing extend over the entire face of the screen excluding a margin of determined width. According to a characteristic of the invention, the grooves extend in at least two different directions by communicating with each other.
• the three-dimensional collector of each electrode is for example a foam or an expanded nickel.
• the glue is for example an epoxy resin.
• the conductive screen is for example a metallic material or a polymer comprising a conductive filler.
• the face of the screen facing the negative electrode is preferably covered with a layer of cadmium or zinc of determined thickness.
• the face of the electrode opposite to that in contact with the conductive screen, is grooved, while the face of the conductive screen in contact with the electrode is not grooved.
• the invention further relates to an alkaline accumulator, in particular of the Ni-Cd, Ni-Hydrides, Ni-Fe, Ni-Zn type, comprising at least one bipolar electrode according to the invention.
• the invention also relates to a method of manufacturing a bipolar electrode. It consists :
• FIGS. 1 and 2 a partial view of a conductive screen of a bipolar electrode according to the invention respectively in top view and in section along the axis A-A,
• - Figure 3 a partial schematic view, in cross section of an alkaline accumulator, in particular a Ni-Cd or Ni-Hydrides accumulator comprising bipolar electrodes according to the invention put in series
• - Figure 4 a detail view in section of a bipolar electrode according to the invention on which the screen and the three-dimensional structure are represented after it has been bonded to the screen and before it is filled with active material.
• a determined pressure is applied to the foam or deployed before polymerization of the adhesive. This pressure must be sufficient to expel the glue which is interposed between the roughness of the three-dimensional collector and the external faces of the screen.
• the present invention consists in replacing the intermediate structure not filled with active material and situated between the active mass of the electrode and the screen by grooving the screen.
• Figures 1 and 2 illustrate an example of grooving 1 on the two faces 2 and 3 of the conductive screen
• the grooves li have a width 1 of between approximately 1 and 5 mm and a depth P of between approximately 0.05 and 0.2 mm and are spaced from approximately 5 to 12 mm.
• the thickness e of the latter must not be too great and, under these conditions, the depth P of the grooves li must not exceed approximately
• the grooving 1 of the screen 4 can be carried out in a single or in several directions, for example, as illustrated in Figures 1 and 2, along two perpendicular axes X and Y, each groove li communicating with the others thus allowing passage gases in all directions.
• the grooves li extend over the entire surface of the faces 2 and 3 of the conductive screen 4 with the exclusion of a margin M of approximately 15 mm around the periphery of the screen 4. These margins allow the fixing of the screen inside an accumulator element.
• the connection between the electrode foam and the bipolar screen is no longer carried out by welding, it becomes possible to use as a screen a conductive polymer (the conduction being, for example, given by a charge in carbon), the density of this material then making it possible to use a screen with a thickness of up to 0.5 mm. Under these conditions, the grooves can have a depth of about 0.2 mm.
• the face of the screen is for example grooved in the same way as that indicated for the face in contact with the positive electrode and coated by cadmium plating or zinc plating to limit the risk of hydrogen evolution.
• the grooving of the screen is ineffective because the grooves are gradually closed by the deposition zinc.
• the face of the zinc electrode, opposite to that in contact with the screen is preferably grooved.
• the grooving of the screen both on the side of the negative electrode and of the positive electrode, therefore allows the easy release of oxygen on the face of the positive electrodes facing the conductive screen and its recombination on the face of the negative electrodes facing the conductive screen. Oxygen is transported from one electrode to the other in the space between the edge of the electrodes and the separator and the wall of the element.
• FIG. 3 illustrates an example of placing bipolar electrodes 5 and 6 in series according to the invention, applied to the production of an accumulator, in particular a Ni-Cd or Ni-Hydrides accumulator.
• a frame 7 maintains the electrodes 5 and 6 and the sealing of the accumulator.
• a bipolar electrode 5 according to the invention comprises a conductive bipolar screen 8, fixed by its ends 9 and 10 to frame 7, a positive electrode 11 and a negative electrode 12 bonded respectively to the faces of the bipolar screen 8 and substantially centered relative to the latter.
• the face of the screen 8 receiving the positive electrode it is provided with grooves 13 i, of the same type as those shown in FIGS. 1 and 2 for example, but on only one face of the screen 8.
• These grooves 13 i allow the evacuation of the oxygen released on the external face of the positive electrode 11.
• the bipolar electrode 5 is immersed by the base of the conductive screen 10 in an electrolyte reserve 14.
• the electrodes 5 and 6 are separated from each other by a separator 15.
• the separator 15 is impregnated with electrolyte and is immersed by its base in the electrolyte reserve 14.
• bipolar electrode according to the invention comprising a positive electrode of the NiOOH / Ni (OH) 2 type and a conductive screen is described below by way of nonlimiting example with reference to FIG. 4.
• the screen 17 consists of a polymer plate made conductive by a carbon charge.
• the polymer is stable in alkaline medium.
• the thickness of the plate 17, overall, is 0.4 mm.
• the grooves 18i located on the face in contact with the positive electrode have a width of 1 mm and a depth of 0.2 mm. The distance between two grooves is 8 mm.
• the grooving extends over the entire surface of the plate 17, excluding a margin M of 15 mm shown in Figures 1 and 2, located around the entire periphery of the plate 20, said margin M, being intended to the sealing of the accumulator.
• the grooved face is covered with a layer of nickel 19, except on the margins M, the thickness of the Ni deposit being 5 ⁇ m.
• the plate 17 in its grooved part has a surface of 200 mm x 200 mm, or 4 dm.
• the nickel foam 20 is constituted by a plate whose thickness is 2.2 mm and the external dimensions 195 mm x 195 mm.
• the opening of its cells 21i is of the order of 0.25 mm, corresponding to the product ppi 125 sold by the company Nitech under the name N 090.
• the adhesive used is an epoxy resin, stable in an alkaline medium, such as the product Scotchweld from the company 3 M. It is fluidized by an appropriate solvent (for example acetone) so that the coating of the external surface of the screen 17 groove leads to the deposition of an adhesive film 22 shown in strong lines in the figure, the thickness of which will not exceed 50 ⁇ m, while being at least equal to 10 ⁇ m.
• an appropriate solvent for example acetone
• the nickel foam 20 rests on the external parts of the screen 17, that is to say on the external parts of the grooves 18i, via its asperities 23i.
• the Ni foam plate 20 is applied to the face of the screen 17 coated with adhesive 22 while maintaining a pressure of between 1.3 and 1.8 kg / cm 2 for at least 0.5 hours.
• the polymerization is carried out in 6 hours. Heating under an infrared ramp enables this operation to be carried out more quickly. After polymerization, the pressure can be removed. It is then possible to coat the foam 20 with the active material (not shown) without the calendering and compacting operations separating the foam 20 from the screen.

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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)
• Battery Electrode And Active Subsutance (AREA)
• Cell Electrode Carriers And Collectors (AREA)
• Secondary Cells (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=9502959

Family Applications (1)

Country Status (7)

Families Citing this family (4)

Family Cites Families (7)

• 1997
  • 1997-01-24 FR FR9700789A patent/FR2758909B1/fr not_active Expired - Fee Related
  • 1997-02-05 JP JP10531658A patent/JP2000507386A/ja active Pending
  • 1997-02-05 EP EP97904495A patent/EP0901690A1/de not_active Ceased
  • 1997-02-05 KR KR1019980707558A patent/KR20000064779A/ko not_active Withdrawn
  • 1997-02-05 WO PCT/FR1997/000230 patent/WO1998033223A1/fr not_active Ceased
  • 1997-02-05 CA CA002249473A patent/CA2249473A1/fr not_active Abandoned
  • 1997-04-23 US US09/142,178 patent/US6106974A/en not_active Expired - Fee Related

Non-Patent Citations (1)

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