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
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
• • 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
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• • 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
  • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound 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
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
  • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• • 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
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
  • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
  • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• • 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
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/531—Electrode connections inside a battery casing
  • H01M50/536—Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding
• • 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
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/531—Electrode connections inside a battery casing
  • H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
• • 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
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/531—Electrode connections inside a battery casing
  • H01M50/534—Electrode connections inside a battery casing characterised by the material of the leads or tabs
• • 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 the field of electrochemical metal-ion generators, which operate according to the principle of insertion or deinsertion, or in other words intercalation-deintercalation, of metal ions in at least one electrode.
• a lithium electrochemical accumulator comprising at least one electrochemical cell constituted by an anode and a cathode on either side of a separator impregnated with electrolyte, two current collectors, one of which is connected to the electrolyte. anode and the other at the cathode, and a housing of elongate shape along a longitudinal axis (X), the housing being arranged to house the electrochemical cell with sealing while being traversed by a portion of the current collectors forming the terminals of output, also called poles.
• the separator may consist of one or more films.
• the housing may include a lid and a container, usually called a bucket, or have a lid, a bottom and a side shell assembled at both the bottom and the lid,
• the present invention aims to provide a part of the electrical connection between at least one electrochemical cell of the accumulator and its output terminals integrated into its housing.
• the invention applies to any electrochemical metal-ion accumulator, that is to say also sodium-ion, magnesium-ion, aluminum-ion ...
• a lithium-ion battery or accumulator usually comprises at least one electrochemical cell C consisting of a separator impregnated with an electrolyte component 1 between a positive electrode or cathode 2 and a negative electrode or anode 3, a current collector 4 connected to the cathode 2, a current collector 5 connected to the anode 3 and finally a package 6 arranged to contain the electrochemical cell with sealing while being traversed by a portion of the current collectors 4 , 5, forming the output terminals.
• the architecture of conventional lithium-ion batteries is an architecture that can be described as monopolar, because with a single electrochemical cell comprising an anode, a cathode and an electrolyte.
• monopolar architecture geometry are known:
• the electrolyte constituent may be of solid, liquid or gel form.
• the constituent may comprise a polymer or microporous composite separator impregnated with organic electrolyte (s) or ionic liquid type which allows the displacement of the lithium ion from the cathode to the anode to a charge and vice versa for a discharge, which generates the current.
• the electrolyte is generally a mixture of organic solvents, for example carbonates in which is added a lithium salt typically LiPF6.
• Lithium cation insertion materials which are generally composite, such as lithium iron phosphate LiFePO 4 , lithium cobalt oxide LiCoO 2 , lithiated manganese oxide, optionally substituted, LiMn 2 0 4 or a base material of
• the negative electrode or anode is very often made of carbon, graphite or Li 10 O 10 O (titanate material), possibly also based on silicon or lithium-based, or tin-based and their alloys or composite formed of silicon.
• the anode and the cathode of lithium insertion material can be deposited according to a usual technique in the form of an active layer on a metal sheet constituting a current collector.
• the current collector connected to the positive electrode is usually aluminum.
• the current collector connected to the negative electrode is generally made of copper, nickel-plated copper or aluminum.
• a Li-ion battery or accumulator uses a couple of materials at the anode and the cathode to operate at a high voltage level, typically around 3.6 volts.
• a Li-ion battery or accumulator comprises a rigid package or housing when the targeted applications are binding where a long life is sought, with for example much higher pressures to be withstood and a stricter required sealing level, typically less than 10 ⁇ 6 mbar.l / s helium, or in high stress environments such as aeronautics or space.
• the main advantage of rigid packages is their high sealing and maintained over time because the closure of the housings is performed by welding, generally by laser welding.
• FIG. 1 One of the types of cylindrical rigid case, usually manufactured for a high capacity Li-ion accumulator with a lifetime greater than 10 years, is illustrated in FIG.
• the housing 6 of longitudinal axis X comprises a cylindrical lateral envelope 7, a bottom 8 at one end, a cover 9 at the other end.
• the cover 9 supports the poles or output terminals of the current 40, 50.
• One of the output terminals (poles), for example the positive terminal 40 is soldered to the cover 9 while the other output terminal, for example the terminal negative 50, passes through the cover 9 with interposition of a not shown seal which electrically isolates the negative terminal 50 of the cover.
• FIGS. 4 to 4B show the photographs of an electrochemical bundle F of shape elongate along a longitudinal axis XI and comprising a single electrochemical cell C such that it is usually wound by winding before the housing steps in a housing, electrical connection to the output terminals of the accumulator and its impregnation with an electrolyte.
• the cell C consists of an anode 3 and a cathode 4 on either side of a separator (not visible) adapted to be impregnated with the electrolyte.
• a separator not visible
• uncoated strips is meant here and in the context of the invention, the end portions of the metal sheets, also called strips, forming the current collectors, which are not covered with an insertion material lithium.
• the objective of the battery manufacturers is to increase the autonomy of a cell constituting the accumulator or their ability to operate at high power regimes while improving their lifetime, ie their number of possible cycles, their lightness and the manufacturing costs of these components.
• Improvement routes for Li-ion accumulators concern, for the most part, the nature of the materials and the methods of elaboration of the electrochemical cell components.
• the patent FR 2094491 discloses an alkaline accumulator whose electrical connection between the wound electrochemical cell and output terminals is obtained by cutting the banks of the electrodes by regularly spaced slots and then radial folding of the edges thus split from the outside of the inside under. the form of scales superimposed so as to form a substantially plane base on which is finally welded a current collector, constituted if necessary by the housing cover.
• the patent application EP 1102337 discloses a Li-ion accumulator whose electrical connection between the electrochemical cell wound and output terminals is obtained by a single pressing of each end of the electrode strips of the wound cell, along the axis of winding, by means of a pressing mandrel and then, by laser welding of each end of the electrode strips with a terminal current collector consisting of a foil in the form of a disk and a connecting tongue itself. even laser welded subsequently to the housing cover, at one end and at the bottom of the housing, at the other end. Ribs are each made on a diameter of the disc and are themselves pressed beforehand the welding against the ends of pressed electrode strips.
• the patent application EP 1596449 describes a Li-ion accumulator whose electrical connection between the wound electrochemical cell and output terminals is obtained firstly by multiple pressing of each lateral end delimited by the uncoated strips of electrodes of the cell. wound, by means of a pressing mandrel of outside diameter between 15 and 20 mm.
• the pressing mandrel moves in a very short stroke alternately from the outside to the inside of the cell parallel to the winding axis by sweeping the entire side surface of the uncoated electrode strips to entangle between them.
• a terminal current collector constituted by a foil in the form of a plane connection strip itself welded by laser or transparency thereafter to a output terminal integrated in the cover at one lateral end and at the bottom of the housing at the other end.
• the mass and the volume of the sidebands not coated with electrodes (banks) necessary for the electrical connection with the current collectors according to the state of the art are not necessarily optimized, which implies in the end a mass and a volume of the accumulator also not yet optimized.
• the inventors found that de facto the banks of the same lateral end were not necessarily electrically connected to each other, in particular the parts of these banks located in the most peripheral zone of the beam. This implies a specific specific capacity of the electrochemical beam decreased, which can be detrimental especially for high power applications for the accumulator.
• the electrolyte filling step in an electrochemical battery of lithium accumulator can be relatively long and delicate because the current collectors of the state of the art as welded on the banks of electrochemical accumulator beam constitute a significant obstacle to the passage of the electrolyte.
• Patent FR 3011128 A1 discloses a new method for producing an electrochemical bundle comprising a combination of two folding steps b / and a electrochemical bundle of separate accumulators in their implementation which make it possible to obtain two distinct zones on at least one , preferably each, of the lateral ends of the beam.
• This process is particularly efficient in terms of electrical conductivity and heat dissipation by the beam.
• its implementation can be restrictive in some applications.
• the object of the invention is to respond at least in part to this need.
• the invention relates, in one of its aspects, to a method for producing an electrochemical bundle (F) of a metal-ion accumulator (A), such as a Li-ion accumulator, in view of its electrical connection to the output terminals of the accumulator, comprising the following steps:
• a / folding or winding on themselves the uncoated strip (s) of the anode and / or the cathode of at least one electrochemical cell constituted by the cathode and the anode on either side of a separator adapted to be impregnated with an electrolyte, so as to form a zone of extra thickness at the end of the strips;
• the method according to the invention is characterized by the winding or folding on itself of the banks of at least one of the two electrodes and compacting by compaction to further densify the wound banks for the purpose of welding with a current collector.
• the metal mat obtained in this way is homogeneous over all the end surface (s) of the electrochemical bundle.
• Axial compression is a simple compaction in one or a few passes, which can be fast.
• the method according to the invention can be implemented for electrodes whose metal strip is relatively thin or relatively thick in the case of application of power or target energy for the accumulator.
• the actual specific capacitance of the electrochemical bundle of an accumulator can be significantly increased.
• the method according to the invention is therefore a very good compromise between the existing techniques of electrical connection by tabs which have the advantage of being simple to implement and the techniques of axial electrochemical bundle tamping which make it possible to obtain good performance in terms of electrical conductivity and heat dissipation of the beam.
• the method is advantageously used for producing accumulators or Li-ion batteries.
• step a / is carried out before step b /.
• step a / is then performed during the cutting step, called “slitting step" of the electrodes.
• step a / is carried out simultaneously in step b /.
• “simultaneously” means in the context of the invention, the fact that we do not add an additional process step to manage, as the setting in another machine, but that the modifying only existing equipment for producing a metal-ion accumulator by adding a station for folding or winding on itself the electrode end.
• this step is performed in the unwound regions of the electrodes, and therefore does not add additional time to the process, since it is the same duration, for example corresponding to an electrode slit and roll it on itself at the same time, or not.
• Realizing the winding or folding of edges during the reposition of the electrodes or during the winding of the beam is advantageous because it does not induce any additional time in the realization of the beam compared to the known technique. In other words, this time is a masked production time. In other words, this makes it possible not to have to manage additional process steps, such as setting up another machine.
• the first or the second variant it is possible to use a set of rollers and successive guides that allow to wind on itself the uncoated strip (bank) of the electrode.
• the technique used may for example be that already used in the paper industry such as book printing or the placing of sheets folded in envelopes for example.
• the axial compression according to step c1 is performed on the entire surface of a lateral end of the beam.
• the axial compression according to step c1 can be performed in one or more times.
• the axial compression comprises a step of axial tamping.
• This axial swaging may be optional or may be the axial compression step in its entirety.
• the tamping can be more or less pronounced, typically on a height between 0.2 to 2mm.
• the method comprises an additional step al /, between step a1 and step b /, of overwriting the zones of oversize.
• the crushing may be at the minimum thickness of the metal strip, or at a thickness to be agreed.
• the zones of extra thickness are further densified.
• the invention further relates to a method of producing an electrical connection portion between an electrochemical bundle of a metal-ion accumulator and one of the output terminals of the accumulator, comprising the following steps:
• the step of welding a base to a current collector is performed by laser welding.
• the invention finally relates to a battery or metal storage battery comprising a housing comprising:
• the negative electrode material (s) is chosen from the group comprising graphite, lithium, titanate oxide Li4Ti05012; or based on silicon or lithium-based, or tin-based and their alloys;
• FIG. 1 is a schematic exploded perspective view showing the various elements of a lithium-ion accumulator
• FIG. 2 is a front view showing a lithium-ion battery with its flexible packaging according to the state of the art
• FIG. 3 is a perspective view of a lithium-ion battery according to the state of the art with its rigid packaging consisting of a housing;
• FIG. 4 is a perspective view of an electrochemical bundle of a lithium-ion battery according to the state of the art, the beam consisting of a single electrochemical cell wound on itself by winding;
• FIG. 4A is a photographic view from above of a lateral end of the electrochemical bundle according to FIG. 4;
• FIG. 4B is a photographic view from above of the other lateral end of the electrochemical bundle according to FIG. 4;
• FIGS. 5 to 5D are diagrammatic views showing the successive steps of an example according to the invention of a process for producing an electrochemical bundle and a part of its electrical connection to the output terminals of the accumulator which 'integrated;
• Figure 5 ⁇ being a variant of Figure 5A;
• FIG. 6A is a schematic view of a first variant of a step of the method according to the invention described with reference to FIGS. 5 to 5D;
• FIG. 6 'A is a schematic view of a second variant of a step of the method according to the invention described with reference to Figures 5 to 5D.
• the inventors propose a new method for producing the electrochemical bundle.
• the metal strips supporting the electrode materials may have a thickness of between 5 and 50 ⁇ .
• anode foil 3 it may advantageously be a copper foil thickness of the order of 12 ⁇ .
• a cathode strip 2 it may advantageously be an aluminum strip thickness of the order of 20 ⁇ .
• Step a / The end of the edge 30 is wound on itself in order to obtain a thickened area 30R (FIG. 5A).
• the end of the edge 30 can always be folded back on itself in order to obtain a thickening zone 30p (FIG. 5 ⁇ ).
• the beam thus has a cylindrical shape elongate along a longitudinal axis X, with at one of its lateral ends, strips 30 of the anode 3 uncoated and at the other 1 1 of its lateral ends of the strips 20 of uncoated cathode.
• the initial beam according to the invention is therefore like that shown in FIGS. 4 to 4B, with, in addition, at the end of the banks 20, 30 zones of excess thickness 20R, 30R (FIG. 5B).
• Step c / Then performs an axial tamping along the X axis of the strips 20, 30 of the electrochemical bundle, over the entire surface of the lateral ends 10, 1 1, and therefore on all the excess areas 20R, 3 OR.
• Axial tamping consists of compression by a flat or structured tool bearing surface substantially equal to the surface of each of the lateral ends of the strips 20 or 30.
• the tool and the electrochemical bundle are arranged coaxially during axial swaging.
• Axial tamping is performed once or several times. It can consist of a compression according to one or more relative movements back and forth, ie at least one round-trip along the X axis of the beam, and until reaching a desired dimension of the beam along X, or an effort maximum compression whose value is predetermined beforehand. This produces on the packed surface 20 RT , RT a substantially flat base, intended to be welded to a current collector ( Figure 5C).

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Secondary Cells (AREA)
• Connection Of Batteries Or Terminals (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=53776863

Family Applications (1)

Country Status (4)

Families Citing this family (9)

Family Cites Families (13)

• 2015
  • 2015-06-22 FR FR1555695A patent/FR3037724B1/fr active Active
• 2016
  • 2016-06-21 US US15/738,830 patent/US10516150B2/en not_active Expired - Fee Related
  • 2016-06-21 WO PCT/EP2016/064301 patent/WO2016207154A1/fr active Application Filing
  • 2016-06-21 EP EP16730414.6A patent/EP3311432A1/de not_active Withdrawn

Also Published As

Similar Documents

Legal Events