Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G2/00—Details of capacitors not covered by a single one of groups H01G4/00-H01G11/00
  • H01G2/12—Protection against corrosion
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/40—Printed batteries, e.g. thin film 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
  • H01M10/04—Construction or manufacture in general
  • H01M10/0436—Small-sized flat cells or batteries for portable equipment
• • 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
  • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
  • H01M50/126—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers
• • 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
  • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
  • H01M50/126—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers
  • H01M50/128—Primary casings; Jackets or wrappings characterised by the material having a layered structure comprising three or more layers with two or more layers of only inorganic material
• • 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
  • H01M50/131—Primary casings; Jackets or wrappings characterised by physical properties, e.g. gas permeability, size or heat resistance
• • 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
  • H01M50/131—Primary casings; Jackets or wrappings characterised by physical properties, e.g. gas permeability, size or heat resistance
  • H01M50/134—Hardness
• • 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
  • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
  • H01M50/233—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders characterised by physical properties of casings or racks, e.g. dimensions
  • H01M50/24—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders characterised by physical properties of casings or racks, e.g. dimensions adapted for protecting batteries from their environment, e.g. from corrosion
• • 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

Definitions

• the invention relates generally to energy storage systems.
• the invention relates more particularly to the protection of these systems against air, in particular for systems deposited on a substrate.
• Electrode storage systems are very often miniaturized. They include inter alia microbatteries and micro-supercapacitors, that is to say systems obtained by depositing materials on a substrate. These materials are, most of the time, reactive to air and / or its compounds (oxygen, nitrogen, humidity).
• microbattery includes both electrochemical systems comprising lithium and its compounds such as glasses based on lithium, as electrochemical systems comprising alkali metals such as sodium and potassium, or even alkaline earths such as beryllium or magnesium.
• micro-supercapacity groups in particular storage systems whose electrodes can be based on carbon or oxides of metals such as the oxides of ruthenium, iridium, tantalum, manganese.
• Microbatteries are mostly obtained in thin layers on a rigid silicon, ceramic or glass substrate, or on a flexible polymer substrate such as kapton or the benzocyclobutene polymer. They can also be associated with integrated circuits. Microbatteries include reactive elements; the anode in particular very often consists of lithium. Metallic lithium reacts quickly to exposure to atmospheric elements such as oxygen, nitrogen, carbon dioxide and water vapor. To ensure good performance of the systems and allow sustainable operation, it therefore provides protection against air.
• microbattery such as cathode films or the electrolyte
• cathode films or the electrolyte even if they are normally less reactive than the anode, also benefit from protection against air.
• 5,561,004 thus suggests the use of polymers including in particular parylene, the use of iron, aluminum, titanium, nickel, vanadium, manganese or chromium, or else the use of LiPON, that is to say a phosphorus and lithium oxynitride on a lithium electrode.
• polymers are not impermeable to air or water vapor, due in particular to their porosity.
• other ceramics have been proposed than LiPON, for example in document WO 02/47187, but the ceramics are fragile and do not withstand mechanical stresses.
• the functioning of the microbattery notably involves variations in the temperature of the elements, and therefore also of any protective layer of these elements. These variations cause significant thermomechanical stresses on these elements and their protective layer. Improvements to the existing protective layers are therefore necessary, in particular as regards their resistance.
• the invention proposes to overcome the drawbacks caused by the existing coating layers.
• the invention relates to a protective layer for a microbattery made of a material, metal or metal alloy, sufficiently soft and / or flexible to absorb significant deformations without revealing cracks.
• the appearance of cracks in a coating layer is indeed detrimental to the operation of an air-sensitive device.
• the protective layer itself be not very reactive with air, and / or not very reactive chemically with the constituents of the element to be protected, and in particular with lithium in the context of microbatteries. It is also preferable that it also has good mechanical compatibility with the constituents of the element to be protected, and in particular good adhesion.
• the material of the layer is selected to have good thermomechanical resistance.
• the material is chosen from rigid materials having a low coefficient of expansion, in particular less than ⁇ .lO "6 ⁇ " 1 : during temperature variations inherent in the operation of a microbattery for example, the material remains identical to itself, without reacting to the stresses generated during thermomechanical stresses.
• the protective layer may consist of a pure metal, or of a nitrided alloy which combines its thermomechanical resistance with reinforced protection against oxidation. It is also possible to opt for a combination of these materials, such as for example a layer of metal combined with a layer of its nitrided alloy.
• the protective layer can also be combined with another protective layer whose material has a very ductile behavior, that is to say that it deforms plastically during thermomechanical stresses without being damaged.
• its Vickers hardness is less than 50, preferably 40, which implies a very low elastic limit.
• the protective layer according to the invention is associated with an insulating layer. This insulating layer can also provide a first barrier against air.
• the protective layer is applied to a microbattery, object of this invention.
• the insulating layer is located on the side of the elements of the microbattery, the layer containing the metal being exterior.
• the preferred embodiment relates to a microbattery totally encapsulated in this layer.
• the invention also relates to a method of protection against air and / or its constituents comprising the coating with a protective layer of metal and / or metal alloy capable of absorbing thermomechanical deformations as described above.
• W and / or Ta and / or Mo and / or Zr and / or WN X and / or TaN x and / or MoN x and / or ZrN x and / or TiN x and / or A1N X are used (x ⁇ 1), possibly associated with Pd and / or Pt and / or Au.
• the method comprises coating with a layer of insulation before coating with the layer containing the metal. It is possible to carry out a preliminary encapsulation before the final coating, which can be kept or eliminated, for example by argon plasma.
• the various coatings are carried out by physical vapor deposition, evaporation, vaporization or spraying, in order to control the coating parameters as much as possible.
• the figure is a schematic representation of the various constituents of a microbattery comprising an encapsulation layer according to the invention.
• a microbattery (10) comprises the substrate (1), the cathode (2a) and anode (2b) collectors, the cathode (3), the electrolyte (4), the anode (5).
• an encapsulation opening is made on the cathode (2a) and anode (2b) collectors.
• the connection of the microbattery to an integrated circuit or to a redistribution substrate is carried out directly on the latter and the connection is carried out directly on the connection pads of an ASIC situated under the microbattery, or by the intermediary of passages ("vias") through the ASIC located under the microbattery.
• the microbattery (10) as such is carried out by known techniques.
• the electrodes (3, 5), in particular when they are made of lithium, are in fact very reactive to air. It is therefore desirable to cover them with a protective layer.
• the other elements (2, 4) can also react with air and it is advantageous to completely encapsulate the microbattery in the bilayer (6, 7).
• the protection of the constituent elements of the microbattery vis-à-vis the air is mainly ensured by a tight metallic layer (7), the metals having a lower air permeability than ceramics and polymers.
• the encapsulation layer according to the invention remains intact and covering, free from cracks.
• thermomechanical stresses In order to reduce the stresses generated during thermomechanical stresses, and to keep these stresses at a low enough level not to cause deterioration, the material is flexible enough to absorb the resulting deformations.
• a rigid material having a low coefficient of expansion is used. This material can be associated with a material having a very ductile behavior allowing it to deform plastically without being damaged.
• the protective layer (7) consists of either a pure metal or an alloy, chosen from the following elements or compounds: W, Ta, Mo, Zr, WN X , TaN x , MoN x , ZrN x , TiN x , A1N X , (x ⁇ 1). It can also consist of a multilayer of these metals and / or alloys.
• the metals were chosen because they are refractory materials with a low coefficient of expansion (W, Ta, Mo, Zr), less than 6.10 "6 ° C _1 .
• W, Ta, Mo, Zr are very resistant to oxidation.
• the protective layer (7) can be a multilayer comprising a highly ductile metal, which has a very low yield strength (Vickers hardness less than 50, preferably less than 40
• Pd, Pt , At are chosen because they offer the additional advantage of being stainless.
• a first layer of electrical insulating coating (6) is applied in direct contact with the microbattery and its substrate.
• This layer is also chemically stable and mechanically compatible with the microbattery. Furthermore, this layer can provide a first barrier against air.
• this layer (6) will be chosen in particular from: a) an oxide whose oxide is more stable than lithium oxide: namely the oxides of Mg, Ca, Be, Ce and La ; b) a “simple” oxide: Si0 2 , MgAl 2 0 4 , Al 2 0 3 , Ta 2 0 5 ; c) a sulfide: zinc sulfide: ZnS; d) a “simple” nitride: Si 3 N 4 , BN; e) a carbide: SiC, B 4 C, WC.
• the encapsulation (6, 7) thus produced is in particular impermeable to H 2 0, 0 2 , N 2 .
• microbatteries as such are produced in a conventional manner in equipment, consisting of a succession of frames, allowing the successive deposition of the different materials constituting the microbattery. The transfer between each frame is carried out via a hermetic enclosure under protection of dried argon making it possible to limit exposure to air.
• This very fine temporary pre-encapsulation layer may be produced for example by chemical vapor deposition from a HMDSO type precursor (Hexamethyldisiloxane).
• HMDSO type precursor Hexamethyldisiloxane
• the type of spraying frame will be of the radiofrequency or ion beam spraying type (IBS) or any other suitable equipment.
• IBS radiofrequency or ion beam spraying type
• PVD physical vapor deposition
• IBS very low deposition temperatures (up to less than 100 ° C).
• the provisional pre-encapsulation layer may be eliminated by a first step of argon plasma or left as it is if it does not harm the adhesion of the ceramic layer.
• the ceramic deposition is carried out at the desired thickness, preferably between 25 nm and 10,000 nm, or even less than 5,000 nm; the rate of deposition of ceramic layers is of the order of 200 nm / hour.
• a second metallic deposit is then carried out in the same way by a PVD technique or by evaporation. This step usually takes place in another deposition frame: in fact, the configuration of the spraying frame for metals is generally different, of the magnetron or direct current type.
• nitrogen is moreover introduced into the deposit frame for the production of a deposit by reactive spraying.
• the speed of deposition of the metal layers is of the order of 2 ⁇ m / hour; the thickness is generally between 50 nm and 10,000 nm.
• the waterproofing of the layers was tested by placing the microbatteries encapsulated in a strongly oxidizing temperature atmosphere (85 ° C / 85% relative humidity), ZnS deposit (100 nm) + W (100 nm) MgO deposit (100 nm) + Ta (100 nm) - Si0 2 deposit ( 100 nm) + W (100 nm) + WN X (100 nm) deposition Si0 2 (100 nm) + AlN x (100 nm) deposition A1 2 0 3 (100 nm) + W (100 nm) No deterioration of the characteristics of the microbatteries after a stay of 200 h have been observed.
• the microbattery thus protected can, depending on the types of application, be encapsulated and interconnected by various techniques known within systems (known for example under the

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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)
• Power Engineering (AREA)
• Inorganic Chemistry (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Secondary Cells (AREA)
• Battery Electrode And Active Subsutance (AREA)
• Laminated Bodies (AREA)

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• 2003
  • 2003-10-16 FR FR0350690A patent/FR2861218B1/fr not_active Expired - Fee Related
• 2004
  • 2004-10-14 US US10/574,756 patent/US20070091543A1/en not_active Abandoned
  • 2004-10-14 JP JP2006534794A patent/JP2007508673A/ja active Pending
  • 2004-10-14 WO PCT/FR2004/002621 patent/WO2005038957A2/fr not_active Ceased
  • 2004-10-14 EP EP04791533A patent/EP1673820A2/de not_active Withdrawn

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