Classifications

• • 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
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
• • 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
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/058—Construction or manufacture
  • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
  • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
• • 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 technical field of the present invention is that of pouch-type electrochemical elements and their manufacturing process.
• An electrochemical element of the pouch type also called a pouch element in what follows, is known from the state of the art. It usually includes a set of plates obtained by stacking at least one positive plate and at least one negative plate separated by a separator. The set of plates is housed in a flexible envelope (or pouch) formed after welding the edges of two multilayer films, each multilayer film comprising a metal layer, generally of aluminum, sandwiched between two layers of plastic material. The envelope thus formed is filled with an electrolyte and then sealed.
• the cover elements are most often made in a rectangular format.
• the positive and negative plates used are rectangular in format.
• the rectangular format is chosen because of the ease of manufacture of such elements and the ease in heat-sealing the straight edges of the two multi-layer films.
• documents KR 101879869 and EP 2 602 840 describe a pocket element of rectangular format.
• FIG. 1 This shows a pocket element (1) of rectangular format, provided with two current output terminals (4, 5), arranged in a compartment of cylindrical section (10). A large space of the interior volume of the compartment is unoccupied. The occupancy rate is only 64%. Consequently, the energy density of the assembly formed by the compartment and the pouch element is penalized.
• the invention provides an electrochemical element of the pouch type comprising: a) a set of plates comprising at least one negative plate, at least one positive plate and at least one separator interposed between said at least one negative plate and said at least one positive plate, in which set of plates:
• said at least one negative plate has two opposite edges in the form of an arc of a circle and two opposite straight edges and
• said at least one positive plate has two opposite edges in the form of an arc of a circle and two opposite rectilinear edges, b) a positive current output terminal connected to said at least one positive plate, a negative current output terminal connected to said at least one negative plate, the positive current output terminal and the negative current output terminal being located on opposite edges of the set of plates.
• the pouch-type electrochemical element typically comprises at least two insulating multi-layer films heat-sealed to form the pouch receiving the set of plates, the positive current output terminal and the negative current output terminal extending out of the volume of the plate. the little bag.
• the positive and negative current output terminals are therefore accessible to an operator outside the volume of the pouch.
• said at least one positive plate comprises a positive current collector and a layer of positive active material deposited on at least one of the faces of the current collector, a portion of the positive current collector located in the vicinity of a rectilinear edges of the positive plate not being covered with positive active material, said current collector portion not covered with positive active material being connected to the positive current output terminal, said at least one negative plate comprises a collector of negative current and a layer of negative active material deposited on at least one of the faces of the current collector, a portion of the negative current collector located in the vicinity of one of the rectilinear edges of the negative plate not being covered with negative active material , said current collector portion not covered with negative active material being connected to the negative current output terminal.
• the electrochemical element further comprises two electrically insulating multilayer films welded at their edges to form a pocket in which the set of plates is housed, the two multilayer films having on their surface an imprint of which the limits coincide with the two opposite edges in the form of an arc of a circle and the two opposite rectilinear edges of said at least one positive or negative plate.
• the electrochemical element can be of the lithium-ion type.
• the subject of the invention is also a battery comprising:
• each element being defined by a plane passing through a positive or negative plate of the element, the planes being parallel to each other,
• the means for compressing the plurality of electrochemical elements comprises:
• a first flange disposed against a wall of an electrochemical element located at one end of the juxtaposition of the plurality of electrochemical elements
• a second flange disposed against a wall of an electrochemical element located at another end of the juxtaposition of the plurality of electrochemical elements.
• the compressive force exerted by the means for compressing the plurality of electrochemical elements is uniformly distributed over the surface of the electrochemical elements.
• the subject of the invention is also a set comprising:
• said at least four rods are arranged in a volume delimited by the wall of the compartment, current output terminals and the rectilinear edge of the elements.
• the subject of the invention is also a method for manufacturing an electrochemical element of the pouch type, said method comprising the steps of: a) providing at least one positive plate and at least one negative plate, said at least one plate negative having two opposite edges in the shape of a circular arc and two opposite straight edges, said at least one positive plate having two opposite edges in the shape of an arc of a circle and two opposite straight edges, b) enveloping said at least one positive plate or said at least one negative plate by a separator, c) stacking said at least one positive plate and said at least one negative plate to obtain a set of plates, d) connecting a positive current output terminal to a straight edge of said at least one positive plate and connect a negative current output terminal to a straight edge of said at least one negative plate, the positive current output terminal and the negative current output terminal being located on opposite edges of the set of plates, e) wrap the set of plates in a pocket obtained by welding several edges two multilayer electrically insulating films.
• the method further comprises, before step e), a step of preforming the two electrically insulating multilayer films, said preforming step consisting in stamping the two electrically insulating multilayer films in order to create an imprint of an electrically insulating multilayer film. positive plate or negative plate on the surface of these two films.
• the method further comprises step f) of filling the pouch with an electrolyte.
• the method further comprises step g) of welding unsealed edges of the two multilayer electrically insulating films in order to obtain the sealing of the pouch-type electrochemical element.
• FIG. 1 schematically shows a cross-sectional view of a cylindrical-shaped compartment housing a rectangular-shaped pocket member according to the prior art.
• FIG. 2 schematically shows a view of a semi-circular pocket element according to the invention.
• FIG. 3 shows schematically a view of a cross section of a cylindrical format compartment housing a semicircular format pocket member according to the invention.
• FIG. 4a shows a top view of a positive plate (left) and a negative plate (right). A portion of the positive current collector not covered with positive active material can be seen on the upper edge of the positive plate. A portion of the negative current collector not covered with negative active material can be seen on the lower edge of the negative plate.
• FIG. 4b shows a top view of a negative plate enveloped by a separator.
• FIG. 4c shows a top view of a set of plates arranged in a jig used for centering the plates.
• FIG. 4d shows a top view of a pocket element according to the invention.
• FIG. 5 represents the variation of the voltage of the element during the discharge of the first cycle.
• FIG. 6 represents on the left the variation of the tension of the pocket element of the example during the first three cycles and on the right the variation of the tension of the pocket element during the last three cycles of the series of 70 cycles .
• the pocket element according to the invention is characterized by a semi-circular format.
• This semi-circular format is achieved through the use of at least one positive plate and at least one negative plate in a semi-circular format.
• semicircular means that said at least one positive plate and said at least one negative plate each have two opposite edges in the shape of an arc of a circle and two opposite straight edges.
• opposite edges refers to the edges located on either side of an axis of symmetry passing through the center of said at least one positive or negative plate.
• a straight edge of said at least one positive plate is connected to a positive current output terminal.
• a straight edge of said at least one negative plate is connected to a negative current output terminal.
• Said at least one positive plate and said at least one negative plate are superimposed and oriented so that the positive current output terminal and the negative current output terminal are disposed on opposite edges of the set of plates resulting from this superposition.
• the electrochemical element has two axes of symmetry, the first being parallel to the straight edges and passing through the center of the positive and negative plates, the second being perpendicular to the straight edges and passing through the center of the positive and negative plates.
• Figure 2 schematically shows a view of a semicircular pocket element (1) according to the invention. This shows the two axes of symmetry AA 'and BB' of the cover element, the two opposite rectilinear edges (2, 2 ') located on either side of the first axis of symmetry AA' and the two opposite edges in the form of a circular arc (3, 3 ') located on either side of the second axis of symmetry BB'.
• the positive (4) and negative (5) current output terminals are located on opposite straight edges of the element and extend in opposite directions.
• said at least one positive plate comprises a positive current collector and a layer of positive active material is deposited on at least one of the two faces of the current collector.
• a portion of the positive current collector located in the vicinity of one of the rectilinear edges of the positive plate is not covered with positive active material.
• Said current collector portion not covered with positive active material serves for connection to the positive current output terminal.
• the portion of the positive current collector not covered with positive active material may be in the form of a strip with a width of about 10 to 20 mm.
• said at least one negative plate comprises a negative current collector and a layer of negative active material is deposited on at least one of the two faces of the current collector.
• a portion of the negative current collector located in the vicinity of one of the rectilinear edges of the negative plate is not covered with negative active material.
• Said current collector portion not covered with negative active material serves for connection to the negative current output terminal.
• the portion of the negative current collector not covered with positive active material may be in the form of a strip with a width of about 10 to 20 mm.
• a set of plates consists of stacking at least one negative plate, at least one positive plate and at least one separator interposed between said at least one negative plate and said at least one positive plate.
• the plate set is inserted into a pocket formed by welding the edges of two multi-layer films.
• Figure 2 shows the heat-sealed edges (6).
• FIG. 3 shows, by comparison with the situation in Figure 1, the best occupancy rate obtained with the element according to the invention.
• the occupancy rate of the internal volume of the cylindrical compartment reaches 84% instead of 64% in the case of a rectangular pocket element.
• the reference numbers used for figure 3 denote the same parts as those used for figure 1.
• the arrangement of the positive and negative current output terminals on opposite edges of the plate set makes it possible to optimize the path of the current lines within the element. This advantage is important when the element is intended to pass strong currents in charge or in discharge, for example a current of at least C, or of at least 2C, or of at least 5C or of at least 10C, C being the nominal capacity of the element.
• the element is said to be of the "power" type.
• the pouch element according to the invention is preferably of the lithium-ion type and allows the passage of strong currents.
• the width of the current output terminals can be increased so that they extend over a greater length of a straight edge. This allows more current to be passed without overheating the current output terminal.
• An element can be rotated by 180 ° around an axis perpendicular to the plane of the element. This rotation allows the position of the positive current output terminal to be exchanged with that of the negative current output terminal. This possibility is interesting because it makes it possible, by a simple rotation of the element, to switch from a parallel connection between two current output terminals of the same polarity of two adjacent elements to a series connection between these two elements.
• the means for compressing the plurality of pouch elements may include:
• a first flange disposed against a wall of an electrochemical element located at one end of the juxtaposition of the plurality of electrochemical elements
• a second flange disposed against a wall of an electrochemical element located at another end of the juxtaposition of the plurality of electrochemical elements.
• the invention takes advantage of the presence of rectilinear edges located on either side of the current output terminals to serve as a fulcrum for these at least four rods.
• Two of the four rods can be placed on either side of the positive current output terminal.
• Two other rods can be placed on either side of the negative current output terminal.
• the two ends of the four rods have a thread intended to receive a nut.
• the tightening of the nuts on the rods allows the two flanges to exert a pressure evenly distributed over the entire surface of the elements.
• the pressure exerted by the flanges can be around 2 bar.
• the pressure exerted on the elements is better distributed than in the case of a pocket element of circular format having only one rectilinear edge.
• the pouch element according to the invention can be placed in a tube-shaped compartment of circular or oval section, having a wall defining a cylindrical or oval interior volume.
• the battery is housed in the cylindrical or oval interior volume of the compartment.
• the rods serving to compress the elements are advantageously arranged in a volume delimited by the wall of the compartment, current output terminals and a rectilinear edge of the elements. Such an arrangement is shown in Figure 3.
• the cross section of the four rods is represented by the reference (7).
• the pouch element can be used in various fields such as aeronautics, automotive, telecommunications, emergency lighting, rail.
• step a) at least one positive plate and at least one negative plate are made available.
• Said at least one positive plate is obtained by depositing on one or both sides of a positive current collector a layer of positive active material.
• the positive current collector is a solid or perforated strip, based on carbon or metal, for example nickel, steel, stainless steel or aluminum, preferably aluminum.
• the current collector can be coated on one or both sides with a carbon layer.
• the positive active material can be any positive active material known in lithium-ion element technology. Mention may be made, without being limiting, of lithiated oxides of transition metals and lithiated phosphates of transition metals.
• Said at least one negative plate is obtained by depositing on one or both sides of a negative current collector a layer of negative active material.
• the negative current collector is a solid or perforated strip, which can be made of copper or a copper-based alloy, or aluminum or an aluminum-based alloy. Preferably, it is made of copper.
• the negative active material can be any negative active material known in lithium-ion element technology. Mention may be made, without being limiting, of graphite and titanium oxides.
• the layers of positive and negative active materials are deposited on their respective current collectors, taking care to reserve on a rectilinear edge of the current collectors a strip which does not carry a layer of active material. This strip not covered with active material will be used to weld with the current output terminal.
• FIG. 4a shows on the left a top view of a positive plate (8) and on the right a top view of a negative plate (9).
• step b) at least one positive plate or at least one negative plate is enveloped by a separator.
• the plate having the largest surface is wrapped. This ensures that there is no portion located at the periphery of a plate which is not electrically isolated from the plate of opposite polarity.
• the negative plate is wrapped.
• Figure 4b shows a separator (14) enveloping a negative plate. The portion of the negative current collector not covered with negative active material which is in the form of a strip (13) is visible.
• step c) said at least one positive plate and said at least one negative plate separated by a separator are stacked to obtain a set of plates.
• Said at least one positive plate and said at least one negative plate are oriented so that the strip not covered with active material of the positive plate and the strip not covered with active material of the negative plate are disposed on opposite edges of the set of plaque.
• Figure 4c shows the centering of the plates (8, 9) in a jig (15).
• connection of the positive current output terminal to the strip not covered with active material of said at least one positive plate is carried out and the connection of the negative current output terminal to the strip not covered with active material of said at least one negative plate.
• This connection can be made by laser welding or by resistance welding or by ultrasonic welding.
• a pouch is manufactured by welding several edges of two electrically insulating multi-layer films, for example by heat-sealing three of the four edges of the two multi-layer films. Insert the set of plates into the pocket.
• FIG. 4d shows a pocket element (1) provided with its two current output terminals (4, 5) and the pocket (16) containing the set of plates.
• the bands visible on the top of the pouch are strips of an electrically insulating adhesive, such as Kapton®, used to hold the plate set and the pouch.
• step e) is preceded by a step of preforming the two electrically insulating multilayer films.
• This preforming step consists in stamping the two electrically insulating multilayer films in order to create an imprint of a positive plate or of a negative plate on the surface of these two films. We will choose the plate with the largest surface. Stamping can be carried out at room temperature using a hydraulic press. This step helps prevent wrinkles from forming on the surface. of the two multi-layer films. Indeed, it has been observed that in the absence of such a preforming step, the semicircular shape of the plates resulted in the formation of folds on the surface of the two multilayer films.
• a pocket element according to the invention with a capacity of 15 Ah was manufactured. Its mass is 0.466 kg and its internal resistance is 2.42 mQ. He underwent 70 cycles. Each cycle consists of a discharge phase comprising: a first discharge of 2 minutes at a rate of 16C, i.e. 240 A, corresponding to a drop in the state of charge of 53% and a second discharge of 15 minutes at a rate of 2C or 15 A, corresponding to an additional drop in state of charge of 47%, recharging according to the following protocol:
• Figure 5 shows the variation in the voltage of the pouch element during the discharge of the first cycle.
• Figure 6 shows on the left the variation of the pocket element tension during the first three cycles and on the right the variation of the pocket element tension during the last three cycles of the series of 70 cycles.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Sealing Battery Cases Or Jackets (AREA)
• Secondary Cells (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=71784125

Family Applications (1)

Country Status (3)

Family Cites Families (7)

• 2020
  • 2020-01-31 FR FR2000962A patent/FR3106939B1/fr active Active
• 2021
  • 2021-01-28 EP EP21702635.0A patent/EP4097782A1/de active Pending
  • 2021-01-28 WO PCT/EP2021/052017 patent/WO2021152032A1/fr not_active Ceased

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