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
  • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
• • 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
  • H01M4/04—Processes of manufacture in general
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C8/02—Pretreatment of the material to be coated
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C8/40—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using liquids, e.g. salt baths, liquid suspensions
• • 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
  • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
  • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
  • H01M10/0566—Liquid materials
  • H01M10/0568—Liquid materials characterised by the solutes
• • 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
  • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
  • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
  • H01M10/0566—Liquid materials
  • H01M10/0569—Liquid materials characterised by the solvents
• • 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
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/134—Electrodes based on metals, Si or alloys
• • 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
  • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
  • H01M4/381—Alkaline or alkaline earth metals elements
  • H01M4/382—Lithium
• • 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
• • 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
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• • 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 to a method for modifying the interfacial resistance of a lithium metal electrode, as well as a lithium metal electrode and a Li-metal battery comprising such an electrode.
• metallic lithium as a negative electrode for batteries has been under consideration for several decades.
• Lithium metal has the advantage of having a high energy density because of its low density and its strong electropositive character.
• the use of lithium metal in a liquid medium leads to a degradation of the electrolyte solution due to contact with lithium, and also poses safety problems due to the formation of dendrites on the surface of the metal, which can lead to a short circuit causing the battery to explode.
• the inorganic fillers are blocked within the polymeric material forming the electrolyte, and therefore have little effect on the interfacial resistance of the lithium electrode, which is the indicative factor for the degradation of the electrolyte at the the surface of the electrode.
• the interfacial resistance increases progressively during the electrochemical process until it reaches a plateau, and the addition of charges in solid electrolytes only has the effect of reducing the value of the interfacial resistance to the plateau. .
• US Pat. No. 5,503,946 proposes an anode for lithium battery covered with a film consisting of carbon or magnesium particles.
• this system allows only a moderate decrease in interfacial resistance.
• the inventors have developed a method for modifying the interfacial resistance of a lithium electrode immersed in an electrolytic solution, which, surprisingly, substantially limits the degradation of the electrolyte in contact with metallic lithium.
• This method therefore makes it possible to envisage the use of lithium metal electrodes in liquid electrolytes, therefore at ambient temperature, for the manufacture of high performance batteries.
• the invention provides a method for modifying the interfacial resistance of a lithium metal electrode immersed in an electrolytic solution, which consists in depositing a film of metal oxide particles on the surface of said electrode.
• Deposition of the particle film protects the surface of the lithium metal electrode, which leads to a significant decrease in the resistance of the interface between the lithium and the electrolyte.
• the deposition is carried out by dispersing the particles in the electrolytic solution, then by sedimentation of said particles on the surface of the electrode.
• Such a deposit method has the advantage of being particularly simple, since the formation of the film is by sedimentation over time of the particles dispersed in the electrolytic solution.
• the metal oxide constituting the particles is chosen for example from Al 2 O 3 , SiO 2 , TiO 2 , ZrO 2 , BaTiO 3 , MgO, LiAlO 2 . These particles are readily available commercially, and are low cost.
• the metal oxide particles prior to deposition, can be modified by grafting on their surface groups having an acid character.
• the metal oxide particles may be Al 2 O 3 particles modified with SO 4 2 "groups .
• the modification of the metal oxide particles may be carried out by bringing the particles into contact with an aqueous solution comprising the acid groups to graft, and then drying and calcination of particles This type of treatment, commonly used in catalytic chemistry, has the advantage of being simple to implement.
• the electrolytic solution typically consists of a lithium salt and a solvent or a mixture of aprotic polar solvents.
• aprotic polar solvents examples include linear ethers and cyclic ethers, esters, nitriles, nitrates, amides, sulfones, sulfolanes, alkylsulfamides and partially halogenated hydrocarbons.
• Particularly preferred solvents are diethyl ether, dimethyl ether, dimethoxyethane, glyme, tetrahydrofuran, dioxane, dimethyltetrahydrofuran, methyl or ethyl formate, propylene carbonate or ethylene carbonate, carbonates.
• alkyls especially dimethylcarbonate, diethylcarbonate and methylpropylcarbonate
• butyrolactones acetonitrile, benzonitrile, nitromethane, nitrobenzene, dimethylformamide, diethylformamide, N- methylpyrrolidone, dimethylsulfone, tetramethylene sulfone, tetraalkylsulfonamides having 5 to 10 carbon atoms, polyethylene glycol of low mass.
• polyethylene glycol dimethyl ether mention may be made of polyethylene glycol dimethyl ether.
• the lithium salt of the electrolyte may be an ionic compound Li + Y " , in which Y " represents an anion with delocalised electronic charge, for example Br “ , C10, ⁇ , PF 6 " , AsF ⁇ “ , R F SO 3 " , (R F SO 2 Z ) 2 N “ , (R F SO 2 ) 3 C “ , C 6 H (6 - X) (CO (CF 3 SO 2 ) 2 C “ ) X OR C 6 H ( 6 - x > (SO 2 (CF 3 SO 2 ) 2 C " ) x, where R F represents a perfluoroalkyl or perfluoroaryl group, with l ⁇ x ⁇ 4.
• Y " represents an anion with delocalised electronic charge, for example Br “ , C10, ⁇ , PF 6 " , AsF ⁇ “ , R F SO 3 " , (R F SO 2 Z ) 2 N “ , (R F SO 2 ) 3 C “ , C
• the solvent of the electrolytic solution is polyethylene glycol dimethyl ether (PEGDME), and the lithium salt is lithium perchlorate (LiClO 4 ).
• PEGDME polyethylene glycol dimethyl ether
• LiClO 4 lithium perchlorate
• the deposition of the metal oxide particles on the surface of the electrode can be performed during the operation of an electrochemical cell comprising an anode formed by said electrode, and a cathode, the anode and the cathode being separated by an electro solution. - lytic. If the electrochemical cell is used as a battery, the deposition can take place either before the battery is put into operation, or during the first cycles of operation of the battery.
• the particles being preferably dispersed in the electrolytic solution, it is possible to let them sediment on the surface of the anode before operating the battery, or to operate the battery as soon as its assembly is complete, the sedimentation then naturally occurring during the first cycles.
• the subject of the invention is a lithium metal electrode for a battery, the surface of said electrode being covered with a film of metal oxide particles.
• the particles constituting the film are Al 2 O 3 particles surface-modified with SO 4 2- groups.
• the invention proposes a lithium metal battery comprising an anode and a cathode separated by an electrolytic solution, characterized in that:
• the anode and the cathode are in the form of parallel sheets, the cathode being above the anode; • the anode is constituted by a lithium sheet whose surface facing the electrolytic solution is covered with a film of metal oxide particles, said particles being as defined above.
• the sheets constituting the anode and the cathode are horizontal or substantially horizontal.
• the cathode may comprise at least one transition metal oxide capable of reversibly intercalating and disintegrating lithium, for example selected from the group consisting of LiCoO 2 , LiNiO 2 , LiMn 2 O 4, LiV 3 O 8, V 2 O 5, 'V 6 Oi 3, LiFePO 4 and Li x MnO 2 (0 ⁇ x ⁇ 0.5), and an electronic conductor (such as carbon black) and a binder, of polymer type.
• the cathode generally further comprises a current collector, for example aluminum.
• the electrolytic solution consists of a lithium salt and a solvent or a mixture of solvents, the salt and the solvent being as defined above.
• the process according to the invention was carried out with suspensions of surface-modified Al 2 O 3 particles by grafting of SO 4 2- groups in an electrolytic solution of LiClO 4 in PEGDME. examples of different grafting rates. Preparation of particles AI 2 O 3 / SO 4 2
• the Al 2 O 3 particles used are sold by ABCR Karlsruche.
• the particle size varies between 1.02 and 1.20 mm.
• the surface modification was carried out by successively implementing the following steps: impregnation of the particles with an aqueous solution of H 2 SO 4 ; drying the particles in two successive stages, respectively at 60 ° C. and 100 ° C. for 24 hours; and then calcining the particles in a stream of dry air at a temperature of 500 ° C. for 24 hours.
• the particles were then crushed for 4 hours at 300 rpm and sieved to obtain a fine and homogeneous powder, the average grain size being less than 10 microns.
• Electrolyte solutions were prepared from the compounds PEGDME (molar mass 500 g.mol -1 ) and LiClO 4 (marketed by Aldrich). were dried under vacuum for three days respectively at 60 0 C and 120 0 C, before being used. Solutions containing from 10 -3 to 3 mol / kg of lithium salt relative to the polymer were prepared. After drying under vacuum for 3 days at 150 ° C., the particles whose preparation was described above were introduced into the electrolytic solutions in a proportion equal to 10% by weight relative to PEGDME.
• the various electrolytic solutions prepared were characterized by measurements of ionic conductivity and by DSC (differential scanning calorimetry).
• the ionic conductivity was determined by the method of the complex impedance, at temperatures ranging from -2O 0 C to 70 0 C.
• the samples were placed between stainless steel electrodes and then placed in a thermostatic bath. Impedance measurements were performed on a Solartron-Schlumberger 1255 reference device in a frequency range of 200000 Hz to 1 Hz.
• the DSC measurements were performed on a Perkin-Elmer Pyris 1 reference apparatus. The samples were first stabilized by slow cooling to -12O 0 C and then heated at 20 ° C. per minute to 150 ° C. 0 C. the error in the measurement of glass transition temperature (Tg) was estimated to be ⁇ 2 ° C.
• electrochemical cells were prepared. The cells are assembled in a glove box under an argon atmosphere. Each cell is arranged vertically so as to maintain the lithium electrodes in the form of pellets, horizontal. For each cell, a first lithium electrode is disposed on a stainless steel piston, itself placed in a glass cell. A circular polyethylene spacer is then added to define a constant distance between the two electrodes. The center of the spacer is filled with the solution electrolytic, then a second lithium electrode and a second stainless steel piston are added. The cell is then sealed.
• Table 2 below indicates the composition of the electrolyte solution introduced into each of the four cells, the concentration of lithium salt being equal to
• FIG. 3 shows the interfacial resistance Ri (in ohms, cm 2 ), as a function of the square root of the time Rt, the time being expressed in days.
• FIG. 4 represents the curves obtained for the cell C ref for the cells C1 to C3, and for a cell CO, containing an electrolytic solution into which were introduced the mineral reference particles PO, that is to say not grafted. by acid functions.
• FIG. 4 shows the potential P, in volts, as a function of time t, in minutes.

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• 2006
  • 2006-06-16 FR FR0605399A patent/FR2902576B1/fr not_active Expired - Fee Related
• 2007
  • 2007-06-08 AU AU2007259117A patent/AU2007259117A1/en not_active Abandoned
  • 2007-06-08 WO PCT/FR2007/000948 patent/WO2007144488A1/fr active Application Filing
  • 2007-06-08 US US12/305,145 patent/US20090280405A1/en not_active Abandoned
  • 2007-06-08 CA CA002653539A patent/CA2653539A1/fr not_active Abandoned
  • 2007-06-08 EP EP07788853A patent/EP2036147A1/fr not_active Withdrawn
  • 2007-06-08 CN CNA2007800222363A patent/CN101467284A/zh active Pending
  • 2007-06-08 BR BRPI0713641-2A patent/BRPI0713641A2/pt not_active Application Discontinuation
  • 2007-06-08 KR KR1020097000121A patent/KR20090019892A/ko not_active Application Discontinuation
  • 2007-06-08 JP JP2009514837A patent/JP2009540518A/ja active Pending
• 2008
  • 2008-11-11 IL IL195222A patent/IL195222A0/en unknown

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