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
  • H01M10/60—Heating or cooling; Temperature control
  • H01M10/61—Types of temperature control
  • H01M10/613—Cooling or keeping cold
• • 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
• • 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
  • H01M10/60—Heating or cooling; Temperature control
  • H01M10/62—Heating or cooling; Temperature control specially adapted for specific applications
  • H01M10/625—Vehicles
• • 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
  • H01M10/60—Heating or cooling; Temperature control
  • H01M10/65—Means for temperature control structurally associated with the cells
  • H01M10/654—Means for temperature control structurally associated with the cells located inside the innermost case of the cells, e.g. mandrels, electrodes or electrolytes
• • 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
  • H01M10/60—Heating or cooling; Temperature control
  • H01M10/65—Means for temperature control structurally associated with the cells
  • H01M10/655—Solid structures for heat exchange or heat conduction
  • H01M10/6552—Closed pipes transferring heat by thermal conductivity or phase transition, e.g. heat pipes
• • 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
  • H01M50/543—Terminals
  • H01M50/547—Terminals characterised by the disposition of the terminals on the cells
  • H01M50/548—Terminals characterised by the disposition of the terminals on the cells on opposite sides of the cell
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2220/00—Batteries for particular applications
  • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
• • 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 cells for storing electricity, particularly for motor vehicle batteries, although the invention is not limited to this field of application.
• an electrochemical cell for storing electricity consists of one or more positive electrodes stacked alternately with one or more negative electrodes and one or more separators so as to separate the positive and negative electrodes, and a waterproof envelope that can be flexible, if one is in the case of "pouch cell", or rigid for a cell called “hard casing”.
• FIG. 1 shows an electrochemical cell 100 comprising an envelope 101 in which several positive electrodes 102, connected to a positive terminal 105, are alternately arranged with negative electrodes 103 connected to a negative terminal 106.
• separators 104 impregnated with electrolyte are formed between each positive and negative electrode. These separators as well as the positive and negative electrodes have a substantially rectangular profile and are placed in a plane parallel to the (x, y) plane which corresponds to the longitudinal plane of the cell.
• a disadvantage of this technique is that the use of spacers between each of the cells significantly increases the volume and mass of the vehicle battery. Moreover, this also generates a relatively high implementation cost, which is not satisfactory.
• Another disadvantage of this technique is that the passage of heat from each of the cells to the neighboring spacer will be conditioned by the contact between the rigid envelope and the cell which is not optimal because the quality of this contact is difficult to control (depending on the conditions of manufacture, handling, ). As a result, an imperfect contact and thus a limited contact surface reduces the heat exchange, and therefore the cooling of the cell, relatively poorly, which is not satisfactory.
• the internal structure of the cell consists of a stack of negative electrodes and positive electrodes separated by separators soaked with electrolyte.
• the thermal conductivity towards the surface of the cell will be limited by the thermal conductivity of the various materials, for example polyolefin (polyethylene, polypropylene) separators having a thermal conductivity of less than 1 Watt per meter per Kelvin, electrodes in particular. aluminum or copper with a conductivity greater than 100 Watts per meter per Kelvin, and by the thermal resistances at the interfaces between the different electrodes and / or separators.
• Cooling techniques using air circulation means on the surface of the cell are also known.
• a disadvantage of such a cooling technique is that it implements means that have a significant size and a relatively high cost which is also not satisfactory.
• the maintenance cost of such a technique is also relatively high.
• the invention particularly aims to overcome at least some of the disadvantages of the prior art.
• an objective of at least one embodiment of the invention is to provide an electrochemical cell for which the contact surface between the edges of the electrodes and the envelope is improved in order to optimize the cooling of the electrochemical cell. by evacuating heat over the entire contact area between the envelope and the electrodes.
• Another objective of at least one embodiment is to reduce the bulk of such electrochemical cells to facilitate implementation on all possible vehicle types, or which can be used in most cases.
• Yet at least one other object of an embodiment of the invention is to provide a solution that is simple to implement and inexpensive. 4. Summary of the invention
• an electrochemical cell for storing electricity comprising an envelope in which are placed:
• said at least two positive electrodes and at least two negative electrodes being alternately stacked in the envelope, and at least one separator being placed between each of said at least two positive and negative electrodes.
• the electrochemical cell further comprises at least one contact element disposed in contact with the positive and negative electrodes and the envelope.
• This contact element optimizes the contact between the envelope and the positive and negative electrodes, and thus increases the heat exchange between the edges of each of the electrodes and the separator with the envelope. Therefore, the heat exchange is favored with the outside of the cell which improves the cooling compared to the techniques of the prior art.
• the invention proposes a novel and inventive approach for optimizing the contact surface between the electrodes and the envelope and thus to improve the cooling of the electrochemical cell by evacuating the heat over the entire contact zone between the electrochemical cell. envelope and the electrodes and more particularly at the edges. Indeed, the exchange of heat is facilitated when it is done by the edges of the cell rather than at the surface, when the electrodes are stacked. When it is on the surface of the cell, the heat exchange is limited by the thermal conductivity of the electrodes and separators. The invention makes it possible to overcome these constraints by allowing an optimal thermal exchange by the edges of the electrodes and the spaters.
• the contact element comprises at least one heat pipe whose first end is connected to the contact element and a second end is formed outside the electrochemical cell.
• the envelope of the cell is made of either a flexible material or a rigid material.
• a flexible material will allow some flexibility of the electrochemical cell and also allow the envelope to adopt substantially the shape of the electrodes.
• a rigid material may form a protective housing for the cells.
• the contact element may be made of polymer or elastomer.
• the positive electrodes and the negative electrodes are of substantially rectangular shape.
• the contact element can be arranged either on the width or the length of the electrodes positive and negative, between the edge of these electrodes and 1 envelope.
• the invention also relates to a battery comprising at least one electrochemical cell and a corresponding vehicle.
• FIG. 1 is a sectional view along the plane (x, z) of an electrochemical cell of the prior art
• FIG. 2 is a sectional view along the plane (x, z) of an electrochemical cell according to a first embodiment of the invention
• FIG. 3 is a sectional view along the plane (x, z) of an electrochemical cell according to a second embodiment of the invention.
• FIG. 4 is a sectional view along the plane (x, z) of a motor vehicle battery using several electrochemical cells according to the second embodiment
• FIG. 5 is a graph showing the evolution of the temperature as a function of time for a cell of the prior art and for a cell according to the invention. 6. Detailed description
• the x-axis is defined as being the longitudinal direction of a cell according to the invention.
• the y and z axes, orthogonal to the x axis, respectively define the width and the thickness of the cell.
• the plane (x, y) corresponds to the plane of the electrodes while the plane (x, z) corresponds to a transversal plane, orthogonal to the plane (x, y)
• the electrochemical cell comprises an envelope 3 which is, in this example, a flexible polymer envelope.
• a plurality of positive electrodes 21 alternating with negative electrodes 22.
• a separator 23 impregnated, in known manner, with an electrolyte thus making it possible to conduct the electric current between the electrodes positive 21 and negative 22.
• the assembly 2 formed by the positive electrodes, the negative electrodes, and the separators has a substantially rectangular profile and is formed on a substantially horizontal plane parallel to the plane (x, y).
• the electrochemical cell 1 also comprises contact elements 4a, 4b disposed at the ends of the positive and negative electrodes in the x direction, that is to say on the width of the electrodes, between the assembly 2 and the envelope 3
• These contact elements which in this example are in the form of a polymer foam such as polyethylene terephthalate (PET), make it possible to optimize the contact between the electrodes and the envelope and thus to increase the conductivity. thermal interface. So, all the heat, or at the very least a large part will be dissipated at the ends of the plane (x, y) which corresponds to the edges of the electrodes.
• PET polyethylene terephthalate
• contact elements that are glued to the package to reduce the risk of detachment of these elements during the life of the cell.
• the contact elements are premolded in the envelope to improve the contact with each of the electrodes.
• Other embodiments may also be provided in which the contact elements are made of elastomer, or in another polymer such as polypropylene (PP) or polyethylene (PE).
• contact elements implemented at the ends of the negative and positive electrodes, but in the direction y, that is to say on the length of the electrodes.
• the cell comprises only one positive electrode and one negative electrode, separated by a separator.
• Embodiments may also be provided in which the envelope is rigid and made of other materials such as metal.
• the electrodes and the separators are not planar but cylindrical circular, and arranged concentrically.
• the contact elements are placed at the ends of the electrodes in the direction x, corresponding to the longitudinal direction of the cell, between the electrodes and the 'envelope.
• FIG. 3 An embodiment can also be imagined in which a single contact element is used at one end of the electrodes in the x direction.
• FIG. 3 a sectional view of an electrochemical cell according to a second embodiment of the invention is now presented.
• the electrochemical cell 1 further comprises a heat pipe 7 whose first end 71 is connected to the contact element 4a and a second end 72 is formed outside the electrochemical cell 1. implanting this heat pipe 7 inside the cell makes it possible to limit the number of physical barriers by creating a "bridge" between the inside of the cell and the outside. This thus promotes the dynamics of heat dissipation inside the cell.
• FIG. 4 shows a sectional view along a plane (x, z) of a motor vehicle battery, that is to say a cross-section, using a plurality of electrochemical cells 1 according to FIG. the invention, each comprising a heat pipe.
• the battery A comprises three electrochemical cells 1a, 1b, the implementations according to the second embodiment presented above. These three electrochemical cells are superimposed along the direction z, corresponding to the direction perpendicular to the plane of the electrodes which are, in this example, rectangular. They are placed in a housing 30 forming the casing of the battery A, this casing further comprising a positive terminal 50 and a negative terminal 60.
• batteries having one or more cells adopting different configurations.
• the cells are for example placed end to end along the x axis, which corresponds to the longitudinal axis of the cells.
• some of the cells are provided with heat pipes while others are not.
• FIG. 5 a graph showing the evolution of the internal temperature (y-axis) as a function of time (x-axis) for a cell of the prior art and for a cell according to FIG. invention.
• This graph G comprises a curve J showing the evolution of the internal temperature of a cell of the prior art as a function of the operating time. Note in this example that the curve J increases rapidly during the first hour then grows more slowly during the next thirty minutes to reach a maximum of 40 degrees. During the remainder of this battery's operating time, the temperature is between 38.5 and 40 degrees Celsius.
• a second curve I of graph G shows the evolution of the internal temperature of an electrochemical cell according to the invention as a function of the operating time. Unlike curve J, curve I grows slowly during the first 45 minutes and then stabilizes at a maximum value of 36 degrees. During the subsequent operation of the cell, the internal temperature will oscillate between 34.5 and 36 degrees Celsius.

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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)
• Secondary Cells (AREA)
• Battery Mounting, Suspending (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (1)

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• 2012
  • 2012-10-22 FR FR1260043A patent/FR2997234B1/fr not_active Expired - Fee Related
• 2013
  • 2013-10-11 EP EP13785546.6A patent/EP2909888A1/de not_active Withdrawn
  • 2013-10-11 KR KR1020157013457A patent/KR102102714B1/ko active IP Right Grant
  • 2013-10-11 US US14/437,260 patent/US10079412B2/en active Active
  • 2013-10-11 CN CN201380064437.5A patent/CN104854755B/zh active Active
  • 2013-10-11 WO PCT/FR2013/052434 patent/WO2014064360A1/fr active Application Filing

Patent Citations (1)

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