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
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/139—Processes of manufacture
  • H01M4/1397—Processes of manufacture of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• • 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
  • H01M4/0438—Processes of manufacture in general by electrochemical processing
  • H01M4/045—Electrochemical coating; Electrochemical impregnation
  • H01M4/0452—Electrochemical coating; Electrochemical impregnation from solutions
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B3/00—Electrolytic production of organic compounds
  • C25B3/01—Products
• • 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
  • H01M10/052—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
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/04—Processes of manufacture in general
  • H01M4/0402—Methods of deposition of the material
  • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
• • 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
  • H01M4/0438—Processes of manufacture in general by electrochemical processing
  • H01M4/0459—Electrochemical doping, intercalation, occlusion or alloying
• • 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
  • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• • 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
  • H01M4/139—Processes of manufacture
  • H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• • 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
  • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
  • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• • 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
  • H01M4/621—Binders
  • H01M4/622—Binders being polymers
• • 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
  • H01M4/621—Binders
  • H01M4/622—Binders being polymers
  • H01M4/623—Binders being polymers fluorinated polymers
• • 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
  • H01M4/624—Electric conductive fillers
  • H01M4/625—Carbon or graphite
• • 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
  • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
  • H01M2004/028—Positive electrodes
• • 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
  • H01M2220/10—Batteries in stationary systems, e.g. emergency power source in plant
• • 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
• • 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
  • H01M2220/30—Batteries in portable systems, e.g. mobile phone, laptop
• • 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 present technology relates generally to the field of processes for the intercalation or re-intercalation of alkali metal ions in electrochemically active materials, for example, for the production of oxides and phosphates of metals comprising a metal. alkaline.
• the positive electrode is typically produced by spreading a suspension of active material, conductive material, and binder onto a current collector, typically aluminum foil, followed by drying.
• the active material is usually a lithiated metal oxide or a lithiated metal phosphate, where the metal may be a transition metal or a combination of two or more transition metals.
• the electrochemical cell is usually assembled with a negative electrode and a separator in the discharged state, i.e. the positive electrode being fully lithiated.
• the active material V2O5 is an exception, it being spread in its non-lithiated form on the current collector. In such a case, the battery is mounted in a fully charged state, which represents a serious safety and fire hazard.
• the electrode materials in which lithium is intercalated are lithium-ion battery anode materials of graphite, silicon oxides and tin oxides.
• the lithium halides used in the process generate toxic and corrosive halogen gases at the counter electrode. Halogen gases can also react with any residual water in the assembly and produce more corrosive acids such as HCl or HF, which requires extra precautions to be taken during the process.
• Sloop proposes that the positive electrode be separated intact from the battery, which is very difficult to apply on a large scale, for example by including the extraction of the electrode roll ("jelly-roll") from a. used battery, unwinding and sorting the electrodes, while handling the entire electrode strip for the following steps.
• a separate electrode will also have the additional shortcomings mentioned above.
• Sloop also refers, but does not demonstrate, the relithiation of the used positive electrode, the latter being in pieces deposited in an electrically charged tray or grid. Poor electrical contact between the electrode pieces and the platen or grid will result in uneven distribution of current and potential promoting other electrochemical reactions (such as the evolution of hydrogen) and resulting in low current efficiency and uneven relithiation throughout the electrode.
• this document relates to a process for the electrochemical alkalization of an electrochemically active material, the process comprising the steps of: a) obtaining a working electrode comprising a working electrode material on a collector current, the working electrode material comprising the electrochemically active material, optionally a binder and / or an electronically conductive material; b) introduction of the working electrode into an electrochemical reactor in continuous and / or batch mode with an inert counter-electrode, and a solution comprising an alkali metal salt in a solvent; c) application of a direct current between the working electrode and the counter electrode to obtain an alkaline electrode comprising an alkaline electrochemically active material; and d) removing the alkaline electrode obtained in step (c) from the electrochemical reactor; wherein the electrochemically active material comprises a metal oxide (including complex oxides), a metal phosphate, a metal silicate, metal sulphate, or a metal oxide (including complex oxides), metal phosphate, metal silicate
• the electrochemically active material is deficient in alkali metal.
• the method comprises converting an electrochemically active material of Formula I:
• A is an alkali metal
• M is a transition metal, a post-transition metal or a combination thereof
• X is selected from P, Si and S;
• O is an oxygen atom
• w is chosen from the numbers 1 to 4 and corresponds to the number of atoms A in the alkaline electrochemically active material
• x is chosen from the numbers 1 to 5 and corresponds to the number of atoms M
• y is selected from the numbers 0 to 2, wherein X is absent when y is zero
• z is chosen from the numbers 1 to 12 and corresponds to the number of oxygen atoms in the formulas
• n denotes the oxidation state of M
• p in Formula I denotes both the average number of missing A atoms and the average increase in the oxidation state of M, wherein p ⁇ w (preferably 0 ⁇ p ⁇ 1); and wherein w, y, z, n and p are chosen in order to obtain a stable and electroneutral compound.
• p w
• A is absent in Formula I
• the electrochemically active material of Formula I is of Formula I (a): M n + P x X y Oz.
• X is phosphorus
• y is 1, and z is 4.
• M is Fe, Ni, Mn, Co or a combination of two or more thereof.
• M is V, Mn, Ni, Co, Fe, Cr, Ti, Zr, Sn or a combination of two or more thereof.
• y is 0 and X is absent.
• A is Li, Na or K, or A is Li.
• the electrochemically active material or the alkaline electrochemically active material is further doped by the partial substitution of M with a transition metal (eg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, W or Y) and / or a metal other than a transition metal (eg, Mg, Ca, Sr, Al, Sb, or Sn).
• a transition metal eg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, W or Y
• a metal other than a transition metal eg, Mg, Ca, Sr, Al, Sb, or Sn.
• the solvent is selected from an aqueous solvent, an organic solvent or a mixture thereof, for example, the solvent is water.
• the alkali metal salt comprises at least one alkali metal sulfate, carbonate, bicarbonate, hydroxide, nitrate, acetate, oxalate, or phosphate salt.
• the alkali metal salt is an alkali metal sulfate.
• the alkali metal salt is sodium bicarbonate. alkali metal, for example, where step (b) and / or (c) is carried out in the presence of carbon dioxide gas.
• the method further comprises a step of adjusting the pH of the solution to a pH suitable for the electrochemically active material of step (a) (eg, for FePC, the pH is adjusted between 5 and 9, preferably between 6 and 7.5).
• the alkali metal of the alkali metal salt is lithium.
• step (c) is performed in continuous or batch mode.
• step (c) is performed in continuous mode where the working electrode is introduced into the electrochemical reactor from one side and moves along a defined path so that the electrode working remains a constant distance from the counter electrode while moving through an electrochemically active zone of the electrochemical reactor in order to maintain a relatively uniform current and potential distribution.
• the rate at which the working electrode moves through the electrochemical reactor is adjusted according to the residence time required for a desired level of alkalination at an applied current density.
• step (c) is performed in a controlled current density mode between the working electrode and the counter electrode.
• step (c) is performed in controlled voltage mode between the working electrode and the counter electrode.
• the electrochemically active material is FePC or partially delithied LiFePO4 and the current density at the working electrode is in the range 0.001 A / g to 100 A / g of active LiFePC, preferably in the range of 1 to 15 A / g of active LiFePC.
• step (c) is carried out at a temperature in the range of 5 ° C to 90 ° C, preferably 25 ° C to 50 ° C.
• step (b) can also include a reference electrode.
• the above method further comprises a step (e) of washing the alkaline electrochemically active material from the alkaline electrode and / or a step of drying the alkaline electrochemically active material from the alkaline electrode. .
• the working electrode material comprises a binder, the binder being selected from fluoropolymer binders and other solvent polymer binders.
• the binder is a fluorinated polymer binder such as PVDF, HFP, PVDF-Co-FIFP or PTFE.
• the binder is a solvating polymer binder chosen from poly (ethylene oxide), poly (propylene oxide), poly (dimethylsiloxane), poly (alkylene carbonate), poly (alkylene sulfone), poly (alkylene sulfonamides), polyurethanes, poly (vinyl alcohol), and copolymers (block, random, alternating, random, etc.) comprising at least one of the preceding polymers or monomers thereof ci, as well as a combination of two or more thereof, these polymers optionally being branched and / or crosslinked.
• the working electrode material comprises an electronically conductive material, which is selected from the group consisting of carbon black (such as Ketjen black MC and Super P MC ), acetylene black (such as Shawinigan black and Denka black TM ), graphite, graphene, carbon fibers or nanofibers (such as carbon fibers formed in the gas phase (VGCF)), carbon nanotubes (for example, single-walled or multi-walled), and a combination of two or more of these.
• carbon black such as Ketjen black MC and Super P MC
• acetylene black such as Shawinigan black and Denka black TM
• graphite graphene
• carbon fibers or nanofibers such as carbon fibers formed in the gas phase (VGCF)
• VGCF gas phase
• carbon nanotubes for example, single-walled or multi-walled
• the working electrode material is an electrode material (eg, a positive electrode material) of a used battery and step (a) includes at least one step of separating the battery. electrode material of the other elements of the used battery and the application of said material to the current collector.
• step (a) comprises mixing the electrochemically active material, the binder and optionally the electronically conductive material in a solvent, applying the mixture to the current collector and drying it.
• this document relates to an electrode obtained by a method as defined above.
• this document relates to a process for the electrochemical alkalization of an electrochemically active material, the process comprising the steps of:
• step (iii) electrochemical treatment of the solution separated in step (ii) to regenerate the reducing agent in the solution.
• the electrochemically active material and the alkaline electrochemically active material are as defined herein.
• the electrochemically active material is deficient in alkali metal.
• the reducing agent is the reducing member of a redox couple having a redox potential lower than that of the electrochemically active material (alkali metal deficient) to be reduced.
• the redox couple comprises an Fe (II) / Fe (III) complex, for example, chosen from [Fe (CN) 6 ] 3 7 [Fe (CN) 6 ] 4 -, [Fe (nta)] / [Fe (nta) j-, [Fe (tdpa)] 2 Y [Fe (tdpa)] 3 -, [Fe (edta)] 7 [Fe (edta)] 2 -, [ Fe (citrate)] / [Fe (citrate)] -, [Fe (TEOA) OH] 7 [Fe (TEOA) OH] -, and [Fe (oxalate)] 7 [Fe (oxalate) j.
• Fe (II) / Fe (III) complex for example, chosen from [Fe (CN) 6 ] 3 7 [Fe (CN) 6 ] 4 -, [Fe (nta)] / [Fe (nt
• step (i) further comprises a step of deoxygenation of the solution.
• steps (i) and / or (iii) are carried out in the presence of a gas making it possible to eliminate the presence of oxygen.
• the alkali metal salt is selected from an alkali metal sulfate, carbonate, bicarbonate, hydroxide, nitrate, acetate, oxalate, phosphate, and combinations thereof.
• the alkali metal salt is an alkali metal sulfate.
• the alkali metal salt is an alkali metal bicarbonate, for example, where step (i) is carried out in the presence of carbon dioxide or gas.
• the method further comprises a step of adjusting the pH of the solution to a pH suitable for the electrochemically active material of step (i) (for example, for FePC, the pH is adjusted between 5 and 9, preferably between 6 and 7.5).
• a pH suitable for the electrochemically active material of step (i) for example, for FePC, the pH is adjusted between 5 and 9, preferably between 6 and 7.5.
• the alkali metal of the salt is lithium.
• the solvent is an aqueous solvent.
• step (iii) of electrochemical treatment is carried out in an electrolytic cell by passing a current between at least one cathode and at least one anode.
• the electrolytic cell includes at least one ionic or nonionic separator installed between the anode and the cathode to protect the regenerated reducing agent.
• the electrolytic cell further comprises a system for keeping the solution deoxygenated, for example, the system comprising maintaining an oxygen-free gas in the electrolytic cell, such as carbon dioxide, nitrogen or argon.
• the electrochemically active material is in the form of a suspension in the solution of step (i), and step (ii) is carried out by filtration, centrifugation or decantation, optionally followed by a step washing.
• the electrochemically active material is included in an electrode material on a current collector (forming an electrode) and step (ii) comprises removing the electrode from the solution, optionally followed by a washing step. .
• the electrode material further comprises a binder, for example, selected from fluorinated polymer binders and other solvating polymer binders.
• the binder is a fluorinated polymer binder (such as PVDF, HFP, PVDF-Co-FIFP or PTFE).
• the binder is a binder solvating polymer chosen from poly (ethylene oxide), poly (propylene oxide), poly (dimethylsiloxane), poly (alkylene carbonate), poly (alkylene sulfone), poly (alkylene sulfonamides), polyurethanes , poly (vinyl alcohol), and copolymers (block, random, alternating, random, etc.) comprising at least one of the foregoing polymers or monomers thereof, as well as a combination of two or more of these, these polymers being optionally branched and / or crosslinked.
• the electrode material further comprises an electronically conductive material, for example, selected from the group consisting of carbon black (such as Ketjen black MC and Super P MC ), acetylene black (such as as Shawinigan black and Denka black MC ), graphite, graphene, carbon fibers or nanofibers (such as carbon fibers formed in the gas phase (VGCF)), carbon nanotubes (for example, single-walled or multi-walled), and a combination of two or more thereof.
• carbon black such as Ketjen black MC and Super P MC
• acetylene black such as as Shawinigan black and Denka black MC
• graphite graphene
• carbon fibers or nanofibers such as carbon fibers formed in the gas phase (VGCF)
• VGCF gas phase
• carbon nanotubes for example, single-walled or multi-walled
• the method further comprises drying the alkaline electrochemically active material.
• this document relates to an electrode comprising the alkaline electrochemically active material obtained by a process as defined here, a binder and optionally an electronically conductive material.
• this document relates to an electrochemical cell comprising a negative electrode, a positive electrode and an electrolyte, in which the positive electrode is an electrode as defined herein, or a battery comprising at least one such electrochemical cell.
• the battery is a lithium battery or a lithium-ion battery.
• the electrochemical cell or battery as defined herein is for use in mobile devices, such as mobile phones, cameras, tablets or laptops, in electric or hybrid vehicles, or in renewable energy storage.
• Figure 1 shows a graph of the rate of leaching during delithiation as a function of time according to Example 1 (a).
• Figure 2 shows the X-ray diffraction patterns of virgin LiFeP04 (top row) and its delithed FePO4 (bottom row) according to Example 1 (a).
• Figure 3 shows the linear scanning voltammetry of an FePO4 electrode made from 0V c. PCO (open circuit potential) at -1V c. DHW (saturated calomel electrode) at a rate of 1mV / s as described in Example 1 (c).
• Figure 4 shows the X-ray diffraction patterns of virgin LiFeP04 (top), delithiated FePO4 (middle) and relithied LiFeP04 (bottom) according to Example 1.
• Figure 5 shows a voltammogram of the galvanostatic relithiation of an FePO4 electrode performed at 10mA according to Example 2.
• Figure 6 shows the X-ray diffraction patterns of virgin LiFeP04 (top), delithiated FePO4 (middle) and bonded LiFeP04 (bottom) according to Example 2.
• Figure 7 shows the galvanic response of two FePC electrodes subjected to a potentiostatic relithiation at -0.2V c. DHW at 25 ° C (dotted line) and 50 ° C (solid line) according to Example 3.
• Figure 8 shows the X-ray diffraction patterns of virgin LiFePC (top), bonded LiFeP04 at 25 ° C (middle) and bonded LiFePC at 50 ° C (bottom) according to Example 3.
• Figure 9 shows the cathodic linear scanning voltammetry of a FeP04 electrode performed at a flow rate of 1 mV / s between 0V c. PCO and -1.1 V c. ECS in a 0.5 M aqueous solution of L1FICO3 according to Example 4.
• Figure 10 shows the galvanic response of two FePC electrodes subjected to potentiostatic relithiation at -0.2V c. DHW at 25 ° C in 0.25M L12SO4 (dotted line) and 0.5M L1FICO3 (solid line) according to Example 4.
• Figure 11 shows the X-ray diffraction patterns of virgin LiFePC (top), delithiated FePO4 (middle) and bonded LiFePC (bottom) according to Example 4.
• Figure 12 shows the variation of current as a function of time for an electrode material applied to an aluminum current collector according to the method of Example 5.
• Figure 13 shows the X-ray diffraction patterns of the electrode materials of virgin LiFeP04 (top), delithiated FePC (middle) and bonded LiFePC (bottom) according to Example 5.
• Figure 14 shows the discharge capacity of connected LiFePC (circles) compared to the reference LiFePC (triangles) according to Example 5.
• Figure 15 shows a voltammogram of the EDTA-Fe (III) solution performed between 2.05 V and 4.25 V vs Li + / Li at a scan rate of 200 mV / sec according to Example 6 (b) .
• Figure 16 shows the polarization curves for a solution of EDTA-LiOH (dotted line) and EDTA-Fe (III) in LiOH (solid line) according to Example 6 (b).
• Figure 17 shows the change in the oxidation-reduction potential of the suspension upon reduction of FePC by EDTA-Fe (II) according to Example 7 (a).
• Figure 18 shows the X-ray diffraction patterns of virgin LiFePC (top), delithiated LiFeP04 (middle) and bonded LiFePC (bottom) according to Example 7 (a).
• Figure 19 shows the change in the oxidation-reduction potential of the suspension upon reduction of FePC by citrate-Fe (II) according to Example 7 (b).
• Figure 20 shows the X-ray diffraction patterns of pristine LiFePC (top), delithiated LiFePO4 (middle) and bonded LiFePC (bottom) according to Example 7 (b).
• Figure 21 shows the variation of the concentration of EDTA-Fe (II) and the redox potential of the solution during the electrolysis presented in Example 8 (a).
• Figure 22 shows the variation of the oxidation-reduction potential of the suspension during the reduction of FePC by EDTA-Fe (II) generated by electrolysis of EDTA-Fe (III) according to Example 8 (b).
• Figure 23 shows the X-ray diffraction patterns of virgin LiFePC (top), delithiated LiFeP04 (middle) and bonded LiFePC (bottom) according to Example 8 (b).
• alkalizing and “alkalizing” as used herein refer to the reduction of an active material comprising a metal, accompanied by the insertion of alkali metal ions into the active material.
• the terms “lithier” and “lithiation” are used when the alkali metal ions are lithium ions.
• the terms “alkaline” and “lithiated” generally denote a material resulting respectively from an alkalination or from a lithiation.
• realcalinate “realcalination”, “relithiate” and “relithiation” refer to the alkalination or lithiation of an active material which has lost or is deficient in alkali metal ions or lithium ions, respectively.
• a first step of this process consists in obtaining a working electrode comprising an electrode material on a current collector.
• the electrode material includes the electrochemically active material to be alkalized and may include other components.
• the electrochemically active material is uniformly dispersed in a binder and optionally a conductive material.
• the electrochemically active material can generally be defined as comprising metal oxides (including complex oxides), metal phosphates, metal silicates, metal sulphates or these partially alkaline oxides, phosphates, silicates or sulphates.
• the electrochemically active material is of Formula I:
• A is an alkali metal (eg Li, Na and K, preferably lithium);
• M is a transition metal, a post-transition metal or a combination thereof
• X is selected from P, Si and S; and O represents oxygen; w is chosen from the numbers 1 to 4 and corresponds to the number of atoms A in the alkaline electrochemically active material; x is chosen from the numbers 1 to 5 and corresponds to the number of atoms M; y is selected from the numbers 0 to 2, wherein X is absent when y is zero; z is chosen from the numbers 1 to 12 and corresponds to the number of oxygen atoms in the formula; n denotes the oxidation state of M; p denotes both the average number of missing A atoms and the average increase in the oxidation state of M, where p ⁇ w (preferably 0 ⁇ p ⁇ 1); and wherein w, y, z, n and p are chosen in order to obtain a stable and electroneutral compound. and the alkaline electrochemically active material obtained by the process is of Formula II:
• AwM n xXyOz (II) where A, M, X, O, n, w, x, y, and z are as defined here.
• X is phosphorus
• y is 1, and z is 4.
• transition metals M include Fe, Ni, Mn, Co or a combination thereof, preferably when X is phosphorus, y is 1 and z is 4.
• the electrochemically active material is FePC or a partially delithiated LiFePC.
• M can also include a metal selected from V, Mn, Ni, Co, Fe, Cr, Ti, Zr, Sn or a combination of two or more thereof.
• y is 0 and X is absent, Formula I representing an oxide or a complex oxide.
• the electrochemically active material and / or the alkaline electrochemically active material can also be doped by the partial substitution (10 mol% or less, or 5 mol% or less) of M, for example, with a transition metal (for example, Ti , V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, W or Y) and / or a metal other than a transition metal (for example, Mg, Ca, Sr, Al, Sb, or Sn).
• a transition metal for example, Ti , V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, W or Y
• a metal other than a transition metal for example, Mg, Ca, Sr, Al, Sb, or Sn.
• an alkali metal deficient material such as that of Formula I or I (a) can be mixed with all the ingredients necessary to prepare an electrode for an energy storage device and be applied to a device. current collector.
• the material to be alkalized may be of commercial origin and included in the working electrode material of the present process to obtain alkalization before use as an electrode in an electrochemical cell.
• the electrochemically active material to be alkalized may be the result of a battery recycling process.
• the electrochemically active material can be in the form of microparticles or nanoparticles and / or can further include a carbon coating.
• the ingredients for the electrode material may further comprise at least one binder, for example a polymeric binder, preferably a polar and solvating polymeric binder.
• Non-limiting examples of solvating polymers which may be suitable for use as positive electrode binders include polymeric binders containing fluorine atoms such as PVDF, HFP, PVDF-Co-HFP and PTFE.
• Other examples of solvating polymeric binders include poly (ethylene oxide), poly (propylene oxide), poly (dimethylsiloxane), poly (alkylene carbonate), poly (alkylene sulfone), poly ( alkylene sulfonamides), polyurethanes, poly (vinyl alcohol), and copolymers (block, random, alternating, random, etc.) comprising at least one of the preceding polymers or monomers thereof, as well as a combination of two or more of these.
• solvating polymers can also be branched and / or crosslinked.
• binders include water soluble binders such as SBR (styrene butadiene rubber), NBR (acrylonitrile butadiene rubber), HNBR (hydrogenated NBR), CHR (epichlorohydrin rubber), ACM (acrylate rubber), and the like. the like, and cellulose-based binders (eg, carboxyalkylcellulose, hydroxyalkylcellulose, and combinations thereof), or any combination of two or more thereof. It is understood that the water soluble binders cannot be used in the present alkalizing process when the solvent of the present process is an aqueous solvent.
• electronically conductive materials include, without limitation, carbon black (such as Ketjen black MC and Super P MC ), acetylene black (such as black Shawinigan et noir Denka MC ), graphite, graphene, carbon fibers or nanofibers (such as carbon fibers formed in the gas phase (VGCF)), carbon nanotubes (for example, single-walled or multi-walled) , and a combination of two or more of these.
• carbon black such as Ketjen black MC and Super P MC
• acetylene black such as black Shawinigan et noir Denka MC
• graphite graphene
• carbon fibers or nanofibers such as carbon fibers formed in the gas phase (VGCF)
• VGCF gas phase
• carbon nanotubes for example, single-walled or multi-walled
• a second step of the process includes introducing the working electrode into an electrochemical reactor with an inert counter electrode, and a solution comprising an alkali metal salt in a solvent.
• the electrochemical reactor may further include a reference electrode (such as a saturated calomel electrode (SCE)).
• the electrochemical reactor can also be equipped with a potentiostat or rectifier for electrolysis.
• the electrochemical reactor is configured for continuous or batch electrolysis and may include additional components such as a stir mode to increase mass transfer to the working electrode and / or a temperature control device.
• the solution included in the electrochemical reactor serves as an electrolyte and comprises at least one salt of the alkali metal to be intercalated in the active material, for example a lithium, sodium or potassium salt, preferably a lithium salt, preferably excluding halide salts.
• suitable salts include the sulphate, carbonate, bicarbonate, hydroxide, nitrate, acetate, oxalate, or phosphate salts of the alkali metal, for example A2SO4 or AHCO3, where A is as defined above.
• the solvent for the solution is an organic solvent, an aqueous solvent or a combination thereof, preferably an aqueous solvent.
• the solvent is water (eg distilled or high purity water).
• a pH adjustment step can also be included in the process.
• the pH of the solution must be adapted to the electrochemically active material (and to its alkaline version), for example, in order to maintain its stability and to avoid its dissolution.
• the pH is adjusted between 5 and 9, preferably between 6 and 7.5.
• the pH can be adjusted by an alkali metal hydroxide.
• a supporting electrolyte can be added to reduce the resistance of the electrolyte.
• the counter electrode is made of a material inert under the electrolytic conditions, for example, platinum, a precious metal oxide, a lead oxide, and may optionally include a layer of a catalytic compound serving to reduce the electrode overvoltage.
• a reaction at the counter electrode can lead to evolution of oxygen, and dimensionally stable anodes can be used as the counter electrode material.
• a third step comprises the application of a direct current between the working electrode containing the electrochemically active material deficient in alkali metal and the counter electrode to obtain an alkaline electrode comprising the alkaline electrochemically active material (for example as defined in Formula II).
• This step can be carried out at a temperature in the range of 5 ° C to 90 ° C, preferably 25 ° C to 50 ° C.
• the electrochemical reactor can operate in continuous or batch mode.
• continuous mode the working electrode enters the electrochemical reactor from one side and follows a defined path so that the working electrode remains a constant distance from the counter electrode while moving through an electrochemically active zone. of the electrochemical reactor in order to maintain a relatively uniform current and potential distribution.
• the speed at which the working electrode moves through the electrochemical reactor depends on the residence time required for the desired level of alkalization and the current densities applied.
• the electrochemical reactor can operate either in controlled current density mode or in controlled voltage mode between the working electrode and the counter electrode.
• the electrochemically active material is FePC or a partially delithied LiFeP04 and the current density at the working electrode is in the range of 0.001 A / g to 100 A / g of active LiFePC, preferably in the range of 1 to 15 A / g of active LiFePC.
• the working electrode is withdrawn from the electrochemical reactor.
• the electrode thus alkalized is then preferably subjected to a washing step in order to remove the excess electrolyte from the alkaline electrode material followed by a drying step to remove the excess washing liquid.
• the reference electrode can be positioned in the reactor to monitor the potential of the working electrode. Its presence will minimize spurious reactions at the working electrode and maximize the efficiency of the alkalinization current.
• a reducing chemical process can also be used for the alkalization of the electrochemically active material as defined herein.
• This alternative alkalization process comprises a reducing agent and further comprises a step of regenerating the reducing agent electrochemically.
• the electrochemically active material can be treated with a solution of the reducing agent and an alkali metal salt in a solvent.
• the solution can be deoxygenated before the addition of the reducing agent and / or the electrochemically active material when these can be easily oxidized in the presence of oxygen.
• this step can also be performed in the presence of a gas which removes the presence of oxygen (such as CO2, N2 or Ar).
• the resulting electrochemically active material and alkaline electrochemically active material are as defined above.
• the electrochemically active material is alkali metal deficient.
• Non-limiting examples of alkali metal salts for use in the chemical reduction step include alkali metal sulfates, carbonates, bicarbonates, hydroxides, nitrates, acetates, oxalates, and phosphates or a combination thereof.
• the solvent used is preferably an aqueous solvent.
• the material to be alkalized can be treated as a suspension in a reactor, separated from the spent reducing agent solution, rinsed and dried and then used as an active electrode material in the manufacture of electrodes.
• Separation of the alkaline material from the spent reducing agent solution can be accomplished by typical methods of physical separation, for example, by filtration, centrifugation, or decantation.
• the separated and dried alkaline material can then be mixed with the components needed to prepare an electrode and applied to a current collector.
• these components can include a binder and optionally an electronically conductive material as defined above.
• the material to be alkalized using this method can be first mixed with the components of the electrode material defined above and then applied to a suitable current collector to obtain an electrode such as the working electrode. described in the previous process.
• the prepared electrode is then treated with the reducing agent solution, for example by soaking in it, washed and dried.
• the spent reducing agent is recovered and then regenerated in a subsequent step.
• the solution containing the spent reducing agent is transferred to an electrochemical (or electrolytic) cell with high efficiency and high current density to reduce (and therefore regenerate) the spent reducing agent which can then be reused to process a material.
• alkali metal deficient for example, the step of regenerating the reducing agent is performed by electrochemical treatment in an electrolytic cell by passing a current between at least one cathode and at least one anode.
• This electrolytic cell may further include at least one ionic or nonionic separator installed between the anode and the cathode in order to protect the regenerated reducing agent.
• the electrolytic cell may also include a system for keeping the solution deoxygenated, for example, comprising maintaining an oxygen-free gas in the electrolytic cell.
• a system for keeping the solution deoxygenated for example, comprising maintaining an oxygen-free gas in the electrolytic cell.
• an oxygen-free gas such as carbon dioxide, nitrogen or argon.
• the current density of the electrolytic cell can be increased by acting on the mass transfer in the cell by well known methods (such as the use of turbulence promoters, increasing the temperature, etc.) as well as by increasing the actual surface area of the cathode (for example, by the use of materials in the form of felts, grid, etc.).
• the cathode material will preferably be selected from those with high hydrogen surge such as graphite, lead, etc.
• the reducing agent can be reused almost indefinitely, it can be considered that only electrons are used as the reducing agent of the electrode material, which can be considered an indirect electrochemical reduction. This process thus has several advantages (economic, environmental, etc.) over the use of a reducing agent without its regeneration.
• redox couples can be used as regenerable reducing agents.
• the chosen redox couple will have a lower redox potential than that of the electrochemically active material (alkali metal deficient) to be reduced.
• the redox couple should have an oxidation-reduction potential below 3.45 Vc. Li / Li + (see A. K. Padhi, et al., J. Electrochem. Soc., 1997, 144, 1188-1194).
• redox couple Another desirable characteristic for the redox couple would be a relatively high solubility, in particular in its oxidized form, to avoid the formation of a precipitate in the presence of the treated electrode material.
• redox couples that could be used include Fe (II) / Fe (III) complexes, exhibiting interesting properties for use with this indirect electrochemical approach.
• These complexes include, for example, [Fe (CN) 6] 3 / [Fe (CN) 6] 4 , [Fe (nta)] / [Fe (nta)] _ , [Fe (tdpa)] 2 / [Fe (tdpa)] 3 , [Fe (edta)] / [Fe (edta)] 2 , [Fe (citrate)] / [Fe (citrate)], [Fe (TEOA) OFI] / [ Fe (TEOA) OFI] ⁇ , and [Fe (oxalate)] 7 [Fe (oxalate)].
• These redox couples are particularly interesting for the alkalization of an electrochemically active material (deficient in alkali metal) containing iron, such as FePC
• Electrodes prepared by the methods defined above can then be used directly for the preparation of electrochemical cells, for example, by stacking the electrode with an active counter electrode, the two electrodes being separated by an electrolyte, such as a liquid electrolyte or gel impregnating a separator, or a solid polymer electrolyte.
• electrolyte such as a liquid electrolyte or gel impregnating a separator, or a solid polymer electrolyte.
• electrochemical cells can also be used in the preparation of electrochemical energy storage devices.
• the material to be alkalized by the present methods can be either a spent electrode material obtained in a battery recycling process, or a new electrode material (or its precursor) to be transformed into a material. electrode discharged before its assembly in the electrochemical cell.
• the present description also contemplates a battery comprising at least one electrochemical cell as defined herein.
• the battery is a lithium or lithium-ion battery.
• the present batteries and electrochemical cells can be used, for example, in mobile devices, such as mobile phones, cameras, tablets or laptops, in electric or hybrid vehicles, or in renewable energy storage.
• Unused cathode material containing mainly LiFePC with small amounts of PVDF and graphite was used to produce delithiated material from LiFePC samples using the method described in patent application US2019 / 0207275 (Amouzegar et al. .). Ten parts of this material were dispersed in 100 parts of an aqueous solution containing H2O2 (the amount of H2O2 was adjusted for an Fe: H2O2 molar ratio of 2: 1.33) in a stirred reactor in which CO2 gas was bubbled under a pressure of 30 psi at room temperature. Filtered samples of the suspension taken at different intervals were analyzed by ICP in order to measure the concentrations of Li, Fe and P. The solid residue from the leach was then separated by centrifugation, washed with deionized water and dried in an oven at 120 ° C for 48 hours.
• Figure 1 shows the leaching rates of Li, Fe and P obtained for each of the batches. These results were then used to calculate the leaching efficiency of each element. It has been observed that after 30 minutes almost 80% Li can be in the solution and after 75 minutes this parameter reaches a value of around 90%. The leaching rates for Fe and P do not exceed 0.5% and 3% respectively, showing very high selectivity and efficiency for lithium extraction.
• the X-ray diffraction spectra of the solid composite sample and the virgin LiFePC sample were obtained using a MiniFlex 600 MC apparatus equipped with a cobalt source and are shown in Figure 2.
• the sample is mainly composed of FePC with some residual LiFePC.
• the X-ray diffraction results confirm a higher delithiation rate than that calculated from the ICP analysis results (90% for the ICP analysis compared to 95% from the diffraction results. ).
• the FePC powder was mixed with conductive carbons (Denka MC black and VGCF MC -H, 1: 1 by weight) and a binder ( PVDF) in proportions by mass of 87.5: 7.5: 5 then dispersed in N-methyl-2-pyrrolidone (NMP) to form a suspension. This suspension is finally spread over a 4.16 cm 2 stainless steel collector using a doctor blade and dried (the final charge of the electrode in terms of FePC was approximately 4.3 mg / cm 2. ). (c) Relithiation of FePO electrode material
• the electrode prepared in (b) was tested as a working electrode in a three-electrode electrochemical set-up.
• a platinum mesh was used as the counter electrode while a saturated calomel electrode (SCE) served as a reference.
• the electrolyte consisted of an aqueous solution of L12SO4 (0.25 M) to which LiOH was added to adjust the pH to 7. The temperature was adjusted to 25 ° C using a double-walled glass electrochemical cell ( thermostatically controlled).
• Figure 3 shows the current voltammetry curves c. potential at a potential sweep speed of 1 mV / s.
• the working electrode was first scanned between its open circuit potential (in this case at 165 mV p. DHW) and -1.0 V p. DHW with a Versastat MC 4 device (Princeton Applied Research). It can be seen that apart from the reduction peak corresponding to the lithiation of FePO4 to LiFePO4, no other reaction takes place in this region of potential. This means that the operation of the cell in this potential window would make it possible to have good coulombic current efficiency for the relithiation process.
• the X-ray diffraction pattern of the relithiated sample is compared to the pattern of a virgin LiFeP04 material and that of the delithied composite sample as shown in Figure 4. It is clearly demonstrated that after relithiation, the structure of the delithed sample is returned to that of the virgin material.
• Example 1 (b) In order to carry out the electrochemical relithiation under conditions more suitable for large-scale industrial operation, the same type of electrode prepared in Example 1 (b) was connected under galvanostatic conditions by applying a constant current of 10 mA. between the cathode (FePC electrode) and the anode (inert electrode, in this case a Pt lattice). The potential of the cathode was measured against an ECS reference electrode in order to determine the time required to re-connect almost all of the delithiated FePO4. The electrolysis was carried out in the same type of solution as in Example 1 (c) and at the same temperature (25 ° C). The variation of the cathode potential as a function of the electrolysis time is shown in Figure 5.
• the initial potential of the cathode was approximately 0 V c. ECS and gradually shifted to more cathodic potentials as a function of time as the degree of lithiation of the cathode material increased. After about 1200 seconds, the electrode potential stabilizes and remains constant at -1.4 VDC. ECS indicating the start of a new electrochemical reaction, which includes the evolution of hydrogen.
• the coulombic efficiency of relithiation was calculated to be more than 80%, thus confirming the predicted electrochemical behavior presented in Example 1, i.e. under certain conditions of current density at the cathode, it is possible to minimize side reactions (such as evolution of hydrogen) in order to achieve high current efficiency.
• Example 2 In order to evaluate the effect of temperature on the lithiation process, two electrodes prepared as in Example 1 (b) were connected at temperatures of 25 ° C and 50 ° C respectively in an aqueous solution of L12SO4 ( 0.5 M) to which LiOH was added to adjust the pH to 7. Relithiation was performed at a constant potential of -0.2 Vc. DHW.
• the X-ray diffractograms in Figure 8 confirm that the two electrodes are highly connected with less than 8% and no residual FePO4 detectable for the tests at 25 ° C and 50 ° C, respectively.
• an electrode similar to that described in Example 1 (b) was connected in an electrochemical cell using a 0.5 M aqueous L1FICO3 solution (produced by bubbling CO2 through a suspension of U2CO3 in water at 30 psi and room temperature). The cell was kept under CO2 by gently bubbling CO2 gas through the electrolyte at pH 7 and 25 ° C.
• Example 1 the same type of electrode prepared in Example 1 (b) was prepared using a 15 ⁇ m thick aluminum current collector coated with a thin layer of carbon.
• the dried iron phosphate powder was mixed with conductive carbons (Denka Black MC and VGCF MC -H, 1: 1 by weight) and PVDF binder in a proportion by weight of 89: 6: 5 and dispersed in N -methyl-2-pyrrolidone (NMP).
• NMP N -methyl-2-pyrrolidone
• a tab of the electrode prepared in (a) with an area of 37.5 cm 2 was installed in an electrochemical cell (using a support SS to maintain a constant distance from the counter electrode) in which a platinum mesh of 90 cm 2 and an ECS electrode have been installed respectively as counter electrode and reference electrode.
• the electrolyte consisted of L12SO4 (0.5 M) and the pH was adjusted to 9 using dilute LiOH.
• the cathode potential was checked at -200mV against ECS with a potentiostat from Princeton Applied Research.
• the electrolysis was carried out with stirring and at a temperature of 25 ° C.
• Figure 12 shows the variation of the current as a function of time. The electrolysis was stopped after the current decreased by 95% (in this case after 2860 seconds) and the working electrode was washed with deionized water and dried.
• the electrochemical properties of the electrode connected in (b) and of a commercial LiFePC material similarly applied to an aluminum current collector have been tested against metallic lithium in button cells.
• the active material loads calculated as mg LiFePC per unit area were 7.32 mg LiFePCWcm 2 and 5.88 mg LiFePCWcm 2 respectively for the bound and virgin LiFePC samples.
• the two cells were cycled in duplicate between 2V and 3.8V at a discharge rate of 1C and a charge rate of C / 4.
• a C / 24 pre-charge / discharge cycle was applied to each button cell prior to the cycling procedure.
• the cycling procedure involved a first C / 12 discharge, which was repeated every 20 cycles in order to monitor the health of the battery.
• Figure 14 shows the discharge capacity curves for these electrode materials. It can be seen that the two electrode materials exhibit very good stability in terms of capacitance (less than 2% loss after 100 cycles). After 100 cycles, the electrochemically connected and reference LiFePO4 materials exhibited good and fairly similar discharge capacities of 138 and 143 mAh / g, respectively, at a discharge rate of 1C. The very small difference in capacitance can be related to the slight difference in active material charge, i.e. the slightly higher charge for the electrochemically bonded material may result in slightly lower capacitance.
• a solution of citric acid was prepared by dissolving 3.18 parts of the acid in 200 parts of water. The solution was then basified to a pH of 6 using 4M LiOH solution. The lithium concentration was adjusted to a minimum of 0.5 M before adjusting the volume to 250 parts by adding the necessary amount of LhSC.Then, to prepare the ferrous solution, 0.56 part of hydrated salt of ferrous sulfate ( FeSO4-7H20) was dissolved in 100 parts of the citric acid solution previously prepared. Likewise, with regard to the ferric solution, 0.21 part of hydrated ferric sulfate (Fe2 (SO4) 3-xH20) was dissolved in 100 parts of the citric acid solution prepared above.
• An EDTA solution was prepared by dissolving 14.6 parts of the salt in its acid form in 100 parts of a 1 M LiOH solution. The solution was then basified to a pH of 6 using a 4M LiOH solution. The lithium concentration was adjusted to a minimum of 0.5M before adjusting the volume to 250 parts by adding the necessary amount of U2SO4.
• ferric solution 1 part of hydrated ferric sulfate (Fe2 (S04) 3-xH20) was dissolved in 100 parts of the previously prepared EDTA solution.
• Each solution was filtered at 0.22 ⁇ m then deoxygenated by injection of argon before their subsequent use. If necessary, the pH of each solution was adjusted to values between 4.5 and 8 using LiOH or H2SO4.
• Figure 16 shows the polarization curves in the case of a solution of EDTA-LiOH and EDTA-Fe (III) in LiOH. It can be observed that the reduction peak of EDTA-Fe (III) appears at less negative potentials than the hydrogen evolution reaction in this medium, which demonstrates the possibility of carrying out the electrochemical regeneration of EDTA-Fe (II ) from EDTA-Fe (III) at reasonable coulombic efficiencies while minimizing the current associated with the formation of hydrogen.
• Example 7 Example 7:
• Example 1 50 ml of the solution prepared according to a protocol similar to that described in Example 6 was contacted with 0.65 g of the FePC prepared. in Example 1 (a) under an argon atmosphere and at 40 ° C.
• the EDTA concentration was increased in order to comply with an EDTA / Fe (II) molar ratio of 4 and the pH was adjusted to 8 with a 1 M LiOH solution in order to maximize the solubility of the redox couple.
• the FePC powder was kept in suspension using a magnetic stirrer and the decrease in the concentration of EDTA-Fe (II) and the appearance of EDTA-Fe (III) were monitored. using an ORP probe placed in the suspension.
• Figure 17 shows the variation of the potential of the suspension during relithiation.
• the potential increase can be observed as EDTA-Fe (II) is oxidized (reducing FePO4 to LiFePO4) to EDTA-Fe (III).
• a relithiation assay was performed using the citrate-Fe (II) solution similarly to the procedure presented for EDTA-Fe (II) in section 7 (a).
• the citrate / Fe (II) ratio was adjusted to 2 by the addition of ferrous sulfate and the pH to 6 with the addition of 1 M LiOH.
• 50 mL of the solution was contacted with 0, 19 g of the FePO4 prepared in Example 1 (a) under an argon atmosphere and at 40 ° C.
• the FeP04 powder was kept in suspension using a magnetic stirrer and the decrease in Concentration of citrate-Fe (II) and the appearance of citrate-Fe (III) were followed using an ORP probe placed in the suspension (FIG. 19).
• a volume of 800 ml_ of an EDTA-Fe (III) solution having an initial Fe (III), U2SO4 and EDTA concentration of 0.08 M, 1 M and 0.2 M, respectively, and of which the pH had been adjusted to 6.3 with LiOH was placed in the catholyte reservoir of an ICI-FM01 filter press electrolysis cell assembly and under the protection of an inert gas (Ar).
• the FM01 cell was assembled with a graphite cathode, a titanium anode covered with a layer of iridium oxide and a cationic membrane of the Nafion MC 324 type.
• the geometric active surface of all the components (cathode, anode and membrane) was 64 cm 2 .
• the flow rate of catholyte and anolyte was 2 liters / min with a linear catholyte velocity of around 16 cm / s.
• the temperature of the electrolysis was controlled to approximately 50 ° C by recirculating a heat transfer liquid heated by a thermostatic bath (PolyScience # PD07R-20-A11 B) through heat exchangers installed in the anolyte and catholyte tanks.
• the electrolysis was carried out by setting the voltage between the anode and the cathode at 1.65 V (Instek # SPS-1230).
• An ORP probe had been placed in the catholyte reservoir in order to follow the evolution of the potential of the solution.
• the concentration of EDTA-Fe (III) in each sample during electrolysis was determined by diluting 1 mL of the sample in 10 mL of a 0.2M EDTA solution in LiOH (pH 7.70 ) and measuring the absorbance of the solution at 470 nm.
• Concentration Total iron was determined by diluting 1000 times in water and adding the iron reagent FerroVer TM from the Hach company and measuring the absorbance at 510 nm.
• the difference between total iron and EDTA-Fe (III) made it possible to assess the concentration of EDTA-Fe (II) formed during electrolysis.
• Figure 21 shows the change in the concentration of EDTA-Fe (II) and the redox potential of the solution during 240 minutes of electrolysis.
• cathode material is not limited to graphite and other cathode materials (preferably those with high hydrogen surge) can be used.
• the EDTA-Fe (II) solution obtained during the electrolysis with the FM01 cell in (a) was then used to carry out the relithiation of the FePC 50 mL of the solution were brought into contact with 0.32 g of the FePC prepared in Example 1 (a) under an argon atmosphere and at 40 ° C.
• the FePC powder was kept in suspension using a magnetic stirrer and the decrease in the concentration of EDTA-Fe (II) and the appearance of EDTA-Fe (III) were monitored. using an ORP probe placed in the suspension.
• Figure 22 shows the variation of the potential of the suspension during relithtiation.

Landscapes

• Chemical & Material Sciences (AREA)
• Electrochemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Inorganic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Battery Electrode And Active Subsutance (AREA)
• Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
• Secondary Cells (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=75911287

Family Applications (1)

Country Status (7)

Family Cites Families (15)

• 2020
  • 2020-11-13 CN CN202080078863.4A patent/CN114729462A/zh active Pending
  • 2020-11-13 US US17/770,817 patent/US20220393146A1/en active Pending
  • 2020-11-13 KR KR1020227019145A patent/KR20220099992A/ko unknown
  • 2020-11-13 JP JP2022527115A patent/JP2023502220A/ja active Pending
  • 2020-11-13 WO PCT/CA2020/051547 patent/WO2021092692A1/fr unknown
  • 2020-11-13 EP EP20887315.8A patent/EP4058621A1/fr active Pending
  • 2020-11-13 CA CA3157867A patent/CA3157867A1/fr active Pending

Also Published As

Similar Documents

Legal Events