Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
  • H01M10/52—Removing gases inside the secondary cell, e.g. by absorption
• • 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
• • 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
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/60—Selection of substances as active materials, active masses, active liquids of organic compounds
• • 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
  • H01M4/626—Metals
• • 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 invention relates to the field of electrochemical energy storage, in particular to batteries with organic electrode materials comprising, as active material, a molecular compound chosen from aromatic dianhydrides and imide derivatives thereof. , in particular the 3,4,9,10-tetracarboxylic acid dianhydride of perylene (symbolized by the abbreviation PTCDA). It relates more particularly to the formulation of a specific electrolyte based on mono- and / or dinitrile solvent (s) for these batteries with organic electrodes, in particular for lithium-ion batteries.
• PTCDA 3,4,9,10-tetracarboxylic acid dianhydride of perylene
• Lithium batteries are increasingly used as stand-alone energy sources, particularly in portable equipment, where they are gradually replacing nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) batteries. This development can be explained by the continuous improvement in the performance of lithium accumulators, thus giving them energy densities markedly higher than those offered by the NiCd and NiMH sectors. Lithium batteries find multiple applications, particularly in new information and communication technologies (NICT), medical devices, electric vehicles, the energy storage of photovoltaic cells, etc.
• NTI new information and communication technologies
• lithium electrochemical generators conventionally operate on the principle of insertion or deinsertion (or intercalation-deintercalation) of lithium on at least one electrode.
• the Li + cations thus go back and forth between the electrodes, positive or negative respectively, on each charge and discharge of the accumulator.
• the active material of the positive electrode is capable of releasing lithium ions at the time of charge and incorporating lithium ions at the time of discharge.
• the active compounds of electrodes used in commercial batteries are, for the positive electrode, lamellar oxides such as LiCoCk, LiNiCk and mixed Li (Ni, Co, Mn, Al) Ck, oxides of spinel structure of compositions close to LiMn 2 0 4 or alternatively of the lithium phosphate type, such as LiM 1 P0 4 with M 1 being chosen from Fe, Mn, Co and mixtures thereof.
• lamellar oxides such as LiCoCk, LiNiCk and mixed Li (Ni, Co, Mn, Al) Ck
• oxides of spinel structure of compositions close to LiMn 2 0 4 or alternatively of the lithium phosphate type, such as LiM 1 P0 4 with M 1 being chosen from Fe, Mn, Co and mixtures thereof.
• the negative electrode is generally carbon (graphite, coke, etc.) or optionally LLTisO ⁇ spinel oxide or a metal forming an alloy with lithium (Sn, Si, etc.).
• organic compounds molecules and polymers
• active electrode material of lithium batteries for their ability to capture lithium from reversible manner by releasing or capturing one or more electrons.
• aromatic dianhydrides such as 3,4,9,10-tetracarboxylic acid perylene (PTCDA, C24H8O6), have been proposed as electroactive electrode materials.
• batteries incorporating electrodes based on an active material of the PTCDA type exhibit a rapid loss of capacity during repeated charge / discharge cycles, linked in particular to a phenomenon of dissolution of the starting material and of the electrochemically generated enolate derivatives, in the battery electrolyte, generally based on a mixture of carbonate solvents, for example based on ethylene carbonate (EC), diethyl carbonate (DEC) and / or dimethyl carbonate (DMC).
• EC ethylene carbonate
• DEC diethyl carbonate
• DMC dimethyl carbonate
• PTCDA poly(N - "- hcxyl-3,4,9,10-perylènc tetracarboxylic) imide (PTCI) [1]
• PTCI poly (N - "- hcxyl-3,4,9,10-perylènc tetracarboxylic) imide
• the present invention aims to provide a novel electrochemical cell for an organic battery, in particular for a lithium-ion battery, having an electrode comprising, as active material, a molecular compound chosen from aromatic dianhydrides and imide derivatives thereof, such as PTCDA, and making it possible to achieve improved electrochemical performance, in particular in terms of stability of the specific capacity during cycling.
• the inventors have observed that the implementation of electrolytes based on mono-nitrile solvents and / or specific dinitriles, preferably based on acetonitrile, makes it possible to avoid the dissolution, in the electrolyte, of the material of electrode based on PTCDA during cycling, and lead to very stable specific capacities during charge-discharge cycles.
• the invention relates, according to a first of its aspects, to an electrochemical cell for an organic battery, in particular for a lithium-ion battery, comprising: - at least one organic electrode comprising, as active material, a molecular compound chosen from aromatic dianhydrides and imide derivatives thereof, in particular 3,4,9,10 -tetracarboxylic acid dianhydride of perylene (PTCDA), or one of their reduced forms; and
• a molecular compound chosen from aromatic dianhydrides and imide derivatives thereof, in particular 3,4,9,10 -tetracarboxylic acid dianhydride of perylene (PTCDA), or one of their reduced forms
• PTCDA perylene
• an electrolyte comprising at least one nitrile solvent chosen from mononitriles of formula Ri-CN with Ri representing a C1 to C3 alkyl group; and dinitriles of formula NC-R2-CN with R2 representing an alkylene group having an even number of carbon atoms.
• An electrochemical cell according to the invention thus advantageously uses an aromatic dianhydride or an imide derivative thereof, for example PTCDA, in the molecular state, without having recourse to a chemical or physical modification of the active material or of the electrode.
• an electrochemical cell according to the invention combining an electrode based on a compound of aromatic dianhydride type, in particular based on PTCDA, and an electrolyte based on mono and solvent (s). / or dinitrile (s) according to the invention exhibit excellent electrochemical performance, in particular in terms of cycling stability and resistance at high charge / discharge rates.
• it has a high reversible capacity that is stable over several hundred cycles, unlike in particular electrochemical cells based on carbonate solvents.
• an electrochemical cell according to the invention advantageously exhibits excellent cycling stability, whether in slow cycling regime (for example, C / 10) than in fast regime (for example, in C regime).
• the invention also relates to the use of one or more nitrile compounds chosen from mononitriles of formula Ri-CN with Ri representing a C1 to C 3 alkyl group, and dinitriles of formula NC-R 2 -CN with R 2 representing a alkylene group having an even number of carbon atoms, as solvent (s) in an electrolyte of an electrochemical cell for an organic battery, in which at least one of the electrodes comprises, as active material, a molecular compound chosen from aromatic dianhydrides , imide derivatives thereof, in particular PTCDA, and their reduced forms.
• active compound of aromatic dianhydride type will denote the compound (s) used as active material of at least one of the electrodes of. an electrochemical cell according to the invention, chosen (s) from aromatic dianhydrides, imide derivatives thereof and their reduced forms.
• the active compound of aromatic dianhydride type used according to the invention can be more particularly chosen from PTCDA, NTCDA, 1,2,4,5-tetracarboxylic acid dianhydride, imide derivatives of PTCDA, NTCDA and 1,2,4,5-tetracarboxylic acid dianhydride, and their reduced one or more electron forms.
• the active compound is chosen from PTCDA, NTCDA, 1,2,4,5-tetracarboxylic acid dianhydride, and their forms reduced to one or more electrons. More preferably, the active compound is PTCDA or one of its forms reduced to one or more electrons.
• nitrile solvents used in the electrolyte of an electrochemical cell according to the invention are more preferably chosen from acetonitrile, propionitrile, butyronitrile, succinonitrile, sebaconitrile and their mixtures.
• the nitrile solvent is acetonitrile.
• the invention also relates, according to another of its aspects, to an organic battery comprising at least one electrochemical cell as defined above.
• Such an organic battery is more particularly a lithium-ion battery.
• FIG 1 shows the evolution of the specific capacity C (in mAh / g) as a function of the number of cycles N, in charge ( ⁇ ) and in discharge ( ⁇ ), for the battery tested in example 1, implementing an electrolyte based on carbonate solvents.
• FIG 2 shows the potential evolution curves (in V vs Li + / Li °) as a function of the specific capacity C (in mAh.g 1 )) during the second charge-discharge cycle at a C / regime 10 batteries prepared according to Example 2, using electrolytes of different types;
• FIG 3 shows the evolution of the specific capacity C (in mAh / g) as a function of the number of cycles N, at increasing speeds (5 cycles at C / 10, C / 5, C / 2, C, 2C and 4C respectively) then at a rate of C, for batteries using electrolytes of different types as described in example 2;
• FIG 4 shows the evolution of the specific capacity C (in mAh / g) as a function of the number of cycles N, for two identical batteries, using an electrolyte based on acetonitrile and a lithium salt LiTFSI, for increasing regimes (5 cycles at C / 10, C / 5, C / 2, C, 2C and 4C respectively) then at a rate of C, as described in example 3.
• FIG 5 shows the evolution curves of the specific capacity C (mAh / g) as a function of the number of cycles N, for batteries using electrolytes based on nitrile solvents of different nature, as described in example 4 .
• FIG 6 shows the evolution curves of the specific capacity C (mAh / g) as a function of the number of cycles, for three identical batteries, using gelled electrodes comprising an electrolyte based on a succinonitrile solvent, prepared according to l Example 5, for different cycling regimes (C / 10 to 4C).
• An electrochemical cell according to the invention more particularly comprises two electrodes of opposite polarity, respectively a positive electrode and a negative electrode, separated by an electrolyte, at least one of the electrodes comprising, as active material, a molecular compound chosen from dianhydrides aromatics and imide derivatives thereof, in particular perylene 3,4,9,10-tetracarboxylic acid dianhydride (PTCDA), or a reduced form thereof.
• a molecular compound chosen from dianhydrides aromatics and imide derivatives thereof, in particular perylene 3,4,9,10-tetracarboxylic acid dianhydride (PTCDA), or a reduced form thereof.
• the term “active electrode material (respectively compound)” means a material (respectively a compound) for inserting / deinserting a cation C n + in which n is 1 or 2 (Li + , Na + , K + , Ca 2+ or Mg 2+ ) from an electrode of an electrochemical generator. More particularly, the active material (compound) of the positive electrode is capable of releasing C n + ions at the time of charging and of incorporating C n + ions at the time of discharge of the electrochemical generator. Conversely, the active material (compound) of the negative electrode is capable of incorporating C n + ions at the time of charge and of releasing C n + ions at the time of discharge of the electrochemical generator.
• Aromatic dianhydride compounds and their imide derivatives, which can be used as active electrode materials, are described in the literature (eg, [2]).
• - Ar represents an aromatic, mono or polycyclic group, preferably formed from 1 to 5 rings, each ring preferably comprising 6 members;
• - X represents O (aromatic dianhydrides of cases), or NR, with R representing a hydrogen atom or an alkyl group -C O (case of imide derivatives);
• Ar can represent a benzene ring or an aromatic group formed from two to five condensed aromatic rings, such as a naphthalene or perylene group.
• the compounds of aromatic dianhydride type used as active material of at least one of the electrodes according to the invention can be more particularly chosen from the following compounds:
• PCTDA Perylene 3,4,9,10-tetracarboxylic acid dianhydride
• NTCDA 1,4,5,8-naphthalenetetracarboxylic acid dianhydride
• the carbonyl groups of compounds of aromatic dianhydride type, used as active material according to the invention are electron acceptor groups and therefore capable of being reduced, and can thus combine, for example with a Li + ion, to form lithium enolate groups.
• the charge / discharge cycle process of the electrochemical cell according to the invention is thus based on a reversible redox reaction of enolization of the carbonyl groups of the active compound (s) used, thus allowing the insertion / deinsertion of the Li cations. + (or Na + , K + , Mg 2+ or Ca 2+ ) at the level of the active material.
• This type of compound can thus enter into the constitution of a positive electrode, when the energy storage device uses a metallic counter-electrode, or into the constitution of a negative electrode, when the energy storage device is in Li-ion (or Na-ion, K-ion, Mg-ion or Ca-ion) configuration.
• the reversible redox reaction on the basis of which the charge / discharge process of the electrochemical cell according to the invention is established can be a one, two, three, or even up to 4 electron redox reaction.
• the active compound can be PTCDA or one of its imide derivatives, or one of their forms reduced to one or more electrons.
• the active compound is PTCDA or one of its reduced forms.
• the charge / discharge cycle process of an electrochemical cell according to the invention can be more particularly based on the redox reaction of reversible enolization to one or two electrons, preferably to two electrons, as shown below, in connection with the insertion / disinsertion of Li + cations.
• the PTCDA is preferably used in the PTCDA form as the active material of the negative electrode, the counter-electrode being a lithiated positive electrode.
• PTCDA used as an active electrode material
• LLPTCDA can alternatively be in the reduced form LLPTCDA, as shown above.
• the active material can be respectively in the reduced form Na 2 PTCDA, K 2 PTCDA, CaPTCDA or MgPTCDA.
• the electrochemical conditions of use for its charge / discharge cycle process can be obtained between potential limits of 0.5 to 1.5 V vs Li + / Li.
• aromatic dianhydride compounds used as an active electrode material according to the invention, may be commercially available or prepared by general methods known to those skilled in the art.
• PTCDA is commercially available, for example from the supplier Sigma-Aldrich or TCI.
• the lithiated form of the compound of aromatic dianhydride type for example the lithiated form of PTCDA
• it can be obtained electrochemically in situ from the use of said compound to prepare an electrode of an electrochemical generator, during the first reduction. The same applies, for example, to the potash and soda forms.
• the compound (s) of aromatic dianhydride type, used as active material of at least one of the electrodes of an electrochemical cell according to the invention advantageously represent from 10% to 99% by mass of the total mass of the electrode. , in particular more than 40% by mass, and more particularly from 80% to 99% by mass, relative to the total mass of the electrode.
• Said compound (s) of aromatic dianhydride type for example PTCDA or one of its reduced forms, can be used, in a conventional manner, together with one or more electronically conductive additive (s).
• Said electronically conductive additive (s) can be chosen from carbon fibers, carbon black, carbon nanotubes, graphene and their analogs, and metallic nanowires, such as for example copper nanowires.
• the organic electrode according to the invention for example based on PTCDA, comprises, as electronically conductive additive, metallic nanowires.
• metallic nanowires are understood to mean a wire whose thickness is between 1 and 100 nanometers and therefore the length can range up to 10 micrometers.
• they can advantageously have a form factor, corresponding to the ratio of the length of the nanowire to its diameter, ranging from 10 to 1,000,000, for example greater than 30.
• these nanowires make it possible to ensure good electronic conduction and have very low percolation thresholds within the electrodes.
• These metal nanowires can be metal nanowires selected from copper, nickel, silver, gold, platinum, titanium, palladium, zinc, aluminum and alloys thereof.
• they are nanowires made of copper, nickel or silver, these being particularly suitable for an active material exhibiting an electrochemical potential ranging from 0 to 3 V vs Li ° / Li +, like PTCDA.
• the metallic nanowires are copper nanowires.
• said electronic conductive additive (s) may be present in the composition of the organic electrode, in an amount of 0.1 to 40%, preferably 1 to 10% by mass, relative to the total mass of the 'electrode.
• said active compound (s) of aromatic dianhydride type, for example PTCDA or one of its reduced forms, and said electronically conductive additive (s) can be used in level of the electrode in a weight ratio of active compound (s) / electronically conductive additive (s) of between 50 and 5, preferably between 20 and 10, in particular between 17 and 15.
• the compound (s) of aromatic dianhydride type for example PTCDA or one of its reduced forms, can be used together with one or more binder (s), in particular one or more polymeric binders.
• binders can be chosen from fluorinated binders, in particular from polytetrafluoroethylene, polyvinylidene fluoride (PvdF), polymers derived from carboxymethylcellulose, polysaccharides and latexes, in particular of the styrene-butadiene rubber type (BR or in English " stryrene-butadiene rubber ').
• a particularly preferred binder is poly (vinylidene fluoride) (PvdF).
• Said binder (s) may be present in an amount less than or equal to 20% by mass, relative to the total mass of the electrode, in particular less than or equal to 10% by mass, in particular less than or equal to 5% by mass , relative to the total mass of the electrode.
• the said active compound (s) of aromatic dianhydride type for example PTCDA or one of its reduced forms
• the said binder (s) can be used at the level of the electrode, in a ratio mass of active compound (s) / binder (s) of between 50 and 1, preferably between 20 and 2.
• the electrode based on said compound (s) of aromatic dianhydride type according to the invention can thus comprise, in addition to said compound (s) of aromatic dianhydride type, for example PTCDA or one of its reduced forms, one or more additive (s) ) electronic conductor (s) and / or one or more binder (s), in particular as described above.
• said compound (s) of aromatic dianhydride type for example PTCDA or one of its reduced forms, one or more additive (s) ) electronic conductor (s) and / or one or more binder (s), in particular as described above.
• an organic electrode used in an electrochemical cell according to the invention can comprise the active compound of aromatic dianhydride type, in particular PTCDA, combined with copper nanowires and poly (vinylidene fluoride).
• each of the electrodes is in contact with a current collector.
• copper, aluminum, nickel, carbon felt, or stainless steel can be used as a current collector for a positive electrode; and copper, or steel, processed into a cut sheet, foamed metal or rolled sheet plate, for example, can be used as a current collector for a negative electrode.
• an electrode according to the invention comprises a copper-based current collector, for example in the form of a copper foil or strip.
• organic electrode based on one or more active compounds of aromatic dianhydride type according to the invention for example based on PTCDA, can be prepared via at least the following steps:
• the solvent used can be an organic solvent, for example chosen from the group comprising N-methyl-2-pyrrolidone (NMP), methyl ethyl ketone (MEK), dimethylformamide (DMF), tetrahydrofuran (THF) and acetone.
• NMP N-methyl-2-pyrrolidone
• MEK methyl ethyl ketone
• DMF dimethylformamide
• THF tetrahydrofuran
• acetone acetone
• Fe solvent can be more particularly N-methyl-2-pyrrolidone (NMP).
• the dispersion can be homogenized before it is spread, for example using a deflocculator or a sonotrode.
• the deposition of said dispersion can be carried out by coating, by a printing technique, by extrusion or by co-rolling. Those skilled in the art are able to adjust the conditions for implementing these different techniques.
• Evaporation can be carried out by drying, for example in an oven, at a temperature of between 20 and 150 ° C, in particular between 50 and 80 ° C, for a period of between 1 and 15 hours.
• the organic electrode based on one or more active compounds of aromatic dianhydride type according to the invention is a gelled electrode comprising, in addition to said active electrode material according to the invention, one or more nitrile compounds and at least one polymer, and advantageously one or more salts, in particular a lithium salt.
• Fe nitrile compound used is preferably a dinitrile compound, preferably succinonitrile.
• Such gelled electrodes have for example been described in document WO 2017/032940.
• the polymer used can be chosen from the group comprising poly (styrene-co-acrylonitrile); poly (butylmethacrylate-co-isobutylmethacrylate); poly (butylmethacrylate); poly (isobutylmethacrylate); poly (butylmethacrylate-co-methymethacrylate); poly (methyl methacrylate) (PMMA); poly (vinylidene-hexafluoropropylene fluoride) (PVdF-HFP); polyethylene oxide (POE), polyvinylpyrrolidone (P VP) and poly (vinylidene fluoride) (PVdF).
• the nitrile compound (s) and / or said salt (s), in particular the lithium salt correspond to the constituents of the electrolyte used in the electrochemical cell according to the invention, as described more precisely below. of text.
• the organic electrode based on one or more active compounds of aromatic dianhydride type according to the invention is a gelled electrode, the porosity of which is filled with the electrolyte used in the electrochemical cell. according to the invention.
• the electrolyte can be directly added to the ink formulation coated on the surface of the current collector, when preparing the electrode as previously described.
• the preparation of a gelled organic electrode can thus comprise the following steps:
• an ink comprising, in one or more solvents, said active electrode material, at least one nitrile compound, preferably dinitrile, at least one polymer and advantageously at least one salt, in particular a lithium salt; and
• a “gelled” electrode is particularly advantageous in the case where the nitrile solvent of the electrolyte, such as succinonitrile, exhibits poor wettability properties with respect to the surface of the electrode.
• the formulation of such a “gelled” electrode makes it possible to optimize the electrolyte / electrode interface of the electrochemical system, insofar as the electrolyte is already present in the porosity of the electrode.
• the formulation of a gel electrode makes it possible to increase the specific capacity of the electrochemical cell.
• the organic electrode based on one or more active compounds of aromatic dianhydride type according to the invention is in the form of an electrode. gelled, comprising the electrolyte based on succinonitrle.
• the formulation of a gel electrode also simplifies the manufacture of the electrochemical system, since it is no longer necessary to fill the cell with a liquid electrolyte once the battery is assembled.
• a gelled organic electrode implemented according to the invention can more particularly comprise from 20 to 50% by mass of a mixture of nitrile compound (s) and of lithium, sodium, potassium, calcium or magnesium salts, in particular lithium salts, preferably from 25 to 45% by weight and more particularly from 30 to 35% by weight, relative to the total weight of the electrode.
• the electrode based on said active compound (s) of aromatic dianhydride type according to the invention may comprise, in addition to said compound (s) of aromatic dianhydride type, by example PTCDA or one of its reduced forms, one or more electronically conductive additive (s) and / or one or more binder (s), in particular as described above, one or more nitrile compounds , for example succinonitrile, and advantageously one or more salts, in particular a lithium salt.
• an organic electrode used in an electrochemical cell according to the invention for a lithium-ion battery can comprise PTCDA combined with copper nanowires, poly (vinylidene fluoride), a nitrile compound, in particular succinonitrile, and a lithium salt.
• An electrochemical cell according to the invention more particularly comprises two electrodes of opposite polarity, respectively a positive electrode and a negative electrode, separated by an electrolyte, at least one of the electrodes being an electrode based on one or more active compounds of type of aromatic dianhydride, as defined above.
• the organic electrode based on said active compound (s) of aromatic dianhydride type according to the invention constitutes the negative electrode of the electrochemical cell according to the invention.
• the nature of the counter-electrode, in particular the positive electrode, is of course chosen with regard to the nature of the desired battery, for example depending on whether it is a Li-ion battery, or even a Li-ion battery. 'a Na-ion, K-ion, Ca-ion or Mg-ion battery.
• the positive counter-electrode can typically be an electrode comprising, as active material, a lithium insertion material of the lithiated oxide type or of the lithiated phosphate type comprising at least one transition metallic element.
• lithiated oxide compounds comprising at least one transition metallic element
• mention may be made of single oxides or mixed oxides that is to say oxides comprising several distinct transition metallic elements) comprising at least one metallic element of transition, such as oxides comprising nickel, cobalt, manganese and / or aluminum (these oxides can be mixed oxides).
• mixed oxides comprising nickel, cobalt, manganese and / or aluminum
• M 2 is an element chosen from Ni, Co, Mn , A1 and mixtures thereof.
• lithiated oxides L1C0O2 LiNiCL and the mixed oxides Li (Ni, Co, Mn) C> 2 (such as Li (Nii / 3Mm / 3Coi / 3) 02) also known. under the name NMC), Li (Ni, Co, A1) C> 2 (such as N i (N io.xCoo.15 A lo.os) Ch also known under the name NCA) or Li (Ni, Co, Mn , A1) 0 2 .
• lithiated phosphate compounds comprising at least one transition metallic element mention may be made of compounds of formula LiM 1 P0 4 , where M 1 is chosen from Fe, Mn, Co and mixtures thereof, such as LiFePCL.
• the counter-electrode of an electrochemical cell for a lithium battery according to the invention is based on LiFePCL.
• the counter-electrode may comprise one or more binders, in particular one.
• polymeric binder such as polyvinylidene fluoride (PvdF)
• electrically conductive adjuvants such as for example carbonaceous materials such as carbon black.
• the counter-electrode can be associated with a metallic current collector, as described above, for example an aluminum strip.
• the counter electrode is preferably separate from a lithium or metallic sodium electrode.
• nitrile solvents are generally unstable at very low potentials on lithium and metallic sodium.
• An electrolyte of an electrochemical device typically comprises at least one salt in one or more solvents to ensure conduction of ions, such as a lithium salt when the device is a lithium battery.
• an electrochemical cell according to the invention uses an electrolyte based on one or more nitrile solvents chosen from:
• Ci to C3 Ci to C3; and - Dinitriles of formula NC-R 2 -CN with R 2 representing an alkylene group having an even number of carbon atoms.
• nitrile solvent is used to denote a solvent chosen from mononitrile and dinitrile compounds, as defined above, and their mixtures.
• the electrolyte can comprise a single mono- or dinitrile solvent, or a mixture of at least two solvents chosen from mono- and di-nitrile solvents.
• solvent means the fact that the mono- or dinitrile compound, or mixture of mono- and / or dinitrile compounds, is capable of dissolving said salt (s).
• nonitrile solvent is intended to denote an organic solvent comprising a single nitrile group (respectively, two nitrile groups) of formula —CN.
• the mononitrile solvent is chosen from acetonitrile (CH 3 CN), propionitrile (CH 3 CH 2 CN) and butyronitrile (CH 3 C 2 H 4 CN).
• the dinitrile solvent can be more particularly chosen from the compounds of formula NC-R 2 -CN with R 2 representing a C 2n H 4n group with n being an integer between 1 and 8, in particular between 1 and 5.
• the dinitrile solvent can be chosen from succinonitrile (C4H4N2) and sebaconitrile (C10H16N2).
• lithium salt mention may be made of LiPFe, FiCICL, L1BF4, LiAsFe, L1CF3SO3, FiN (CF3S02) 3, LiNfCLFsSCL), lithium bistrifluoromethylsulfonylimide FiN [S0 2 CF 3 ] 2 (known as abbreviation FiTFSI), lithium bis (fluorosulfonyl) amide (known by the abbreviation FiFSI) FiN [S0 2 F] 2 and mixtures thereof.
• FiTFSI lithium bistrifluoromethylsulfonylimide FiN [S0 2 CF 3 ] 2
• FiFSI lithium bis (fluorosulfonyl) amide
• the electrolyte comprises, as the lithium salt, LiPFe or FiTFSI, preferably FiTFSI.
• Fe or said salts, for example lithium salt may be present in the electrolyte, in a content ranging from 0.3 M to 3 M.
• the electrolyte can be in liquid or gel form.
• the liquid electrolyte according to the invention can be made to impregnate a separator element arranged between the negative electrode and the positive electrode of the electrochemical cell.
• This separator can be made of a porous material, such as a polymeric material, capable of accommodating the liquid electrolyte in its porosity.
• the electrolyte used according to the invention is devoid of carbonate solvent.
• the electrolyte does not include any solvent other than said mono- and / or dinitrile compound (s) as defined above.
• the nitrile solvent (s) according to the invention preferably represent more than 40% of the total volume of the electrolyte, in particular more than 80% of the total volume of the electrolyte.
• the electrolyte of an electrochemical cell for an organic battery according to the invention can be formed from one or more nitrile solvents as defined above, and from one or more salts, for example of a lithium salt for a lithium battery.
• an electrolyte of an electrochemical cell for a lithium battery according to the invention comprises, or even is formed, of one or more nitrile solvents, preferably acetonitrile and at least one lithium salt, in particular LiTFSI or LiPFe.
• an electrochemical cell for a lithium battery according to the invention comprises:
• a positive counter-electrode preferably comprising, as active material, LiFePCL;
• electrolyte disposed between said positive electrode and said negative electrode, said electrolyte comprising at least one nitrile solvent as defined in claim 1 or 9, preferably acetonitrile, and a lithium salt, preferably LiPFe or LiTFSI.
• said negative electrode comprises, besides the PTCDA, copper nanowires as an electronically conductive additive, and a polymer binder, in particular polyvinylidene fluoride.
• the positive electrode comprises, in addition to LiFePCL, an electronically conductive additive, for example carbon black (Super P), and a polymeric binder, in particular polyvinylidene fluoride.
• said electrolyte is formed from said lithium salt in one or more nitrile solvents according to the invention.
• the electrolyte in particular when the nitrile solvent for the electrolyte used is succinonitrile, the electrolyte can be introduced directly during the formulation of the ink used for the preparation of the PTCDA-based electrode. , and remains contained in the electrode after its realization.
• An electrochemical cell according to the invention comprising an organic electrode based on one or more active compounds of aromatic dianhydride type, in particular based on PTCDA, and an electrolyte based on nitrile solvent (s) such as (s) ) as defined above, is intended to enter into the constitution of batteries, and in particular for lithium (Li-ion), sodium (Na-ion), potassium (K-ion) and calcium batteries (Ca-ion) or magnesium (Mg-ion).
• nitrile solvent s
• the invention also relates, according to another of its aspects, to an organic battery comprising at least one electrochemical cell as described above.
• it is a lithium-ion battery.
• the remainder of the battery can be formed using conventional methods.
• lithium-ion batteries have an architecture with two electrodes (a positive electrode and a negative electrode), both coated on an electrically conductive current collector, arranged on either side of an organic separator or inorganic.
• the two mounting techniques of this architecture currently the most used are the winding (winding of the various constituents in a cylindrical or prismatic geometry) and the stack (stacking layer by layer of the various elements).
• winding winding of the various constituents in a cylindrical or prismatic geometry
• stack stacking layer by layer of the various elements
• a commercially available PTCDA powder is dispersed with copper nanowires (CuNW) (prepared according to the protocol described in document WO2017 / 137591) in an 8% solution of polyvinylidene fluoride (PvdF) in N- methylpyrrolidinone in a proportion of 85% PTCDA / 5% CuNW / 10% PvdF (by weight), then the formulation is coated on a copper strip.
• CuNW copper nanowires
• PvdF polyvinylidene fluoride
• electrodes After drying at 55 ° C. overnight, electrodes are cut and dried under vacuum for 48 hours.
• Electrodes of composition 90% LiFeP0 4.5 % Super P, 5% PvdF, are prepared according to the same process.
• Electrodes are assembled in a glove box in a battery using two polyolefin separators, with an electrolyte based on carbonates (mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC)) and LiPFe salts.
• carbonates mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC)
• LiPFe salts LiPFe salts
• Electrochemical tests are carried out by galvanostatic cycling at a rate of C / 10 with potential terminals set at [0.5; 1.5 V]
• a PTCDA powder is dispersed with copper nanowires (CuNW) in an 8% solution of polyvinylidene fluoride (PvdF) in N-methylpyrrolidinone in a proportion of 85% PTCDA / 5% CuNW / 10 % PvdF (by weight), then the formulation is coated on a copper strip.
• CuNW copper nanowires
• PvdF polyvinylidene fluoride
• electrodes After drying at 55 ° C. overnight, electrodes are cut and dried under vacuum for 48 hours.
• Electrodes of composition 90% LiFePCE, 5% Super P, 5% PvdF, are prepared according to the same process.
• Electrodes are assembled in a glove box within a battery using two polyolefin separators with different electrolytes formed from an ether type solvent (dimethyl ether (DME), tetrahydrofuran (THF)), carbonate (dimethyl carbonate) (DMC)), lactone (gamma-butyrolactone (GBL)), mono-nitrile (acetonitrile (CH 3 CN)) or ionic liquid (PyrFSI ⁇ ), and a lithium or sodium salt (LiFSI, LiTFSI, NaPFe ).
• ether type solvent dimethyl ether (DME), tetrahydrofuran (THF)
• carbonate dimethyl carbonate
• DMC carbonate
• GBL gamma-butyrolactone
• PyrFSI ⁇ mono-nitrile
• LiFSI lithium or sodium salt
• LiTFSI LiTFSI, NaPFe
• Electrochemical tests are carried out in galvanostatic cycling at increasing regimes (C / 10 to 4C), with potential limits set at [0.5; 1.5 V]
• Figure 2 shows the curves of the potential as a function of the specific capacity, during the second charge-discharge cycle at a C / 10 regime.
• Figure 3 shows the evolution of the specific capacity C (in mAh / g) as a function of the number of cycles N, at increasing speeds (5 cycles at C / 10, C / 5, C / 2, C, 2C and 4C respectively) then at a regime of C.
• a high capacity in the second charge-discharge cycle is obtained for the battery using the acetonitrile-based electrolyte. Also, the capacity of the battery using the nitrile solvent remains stable with cycling.
• a PTCDA powder is dispersed with copper nanowires (CuNW) in an 8% solution of polyvinylidene fluoride (PvdF) in N-methylpyrrolidinone in a proportion of 85% PTCDA / 5% CuNW / 10 % PvdF (by weight), then the formulation is coated on a copper strip.
• CuNW copper nanowires
• PvdF polyvinylidene fluoride
• electrodes After drying at 55 ° C. overnight, electrodes are cut and dried under vacuum for 48 hours.
• Electrodes of composition 90% LiFePCL, 5% Super P, 5% PvdF, are prepared according to the same process.
• Electrodes are assembled in a glove box in a battery using two polyolefin separators, with an electrolyte based on acetonitrile and LiTFSI salts.
• Electrochemical tests are carried out in galvanostatic cycling at increasing regimes (C / 10 to 4C) with potential limits set at [0.5; 1.5V].
• a PTCDA powder is dispersed with copper nanowires (CuNW) in an 8% solution of polyvinylidene fluoride (PvdF) in N-methylpyrrolidinone in a proportion of 85% PTCDA / 5% CuNW / 10 % PvdF (by weight), then the formulation is coated on a copper strip.
• CuNW copper nanowires
• PvdF polyvinylidene fluoride
• electrodes After drying at 55 ° C. overnight, electrodes are cut and dried under vacuum for 48 hours.
• Electrodes of compositions 90% LiFePCL, 5% Super P, 5% PvdF, are prepared according to the same process.
• Electrodes are assembled in a glove box in a battery using two polyolefin separators, with different electrolytes based on different nitrile solvents (acetonitrile (CFLCN), succinonitrile (SN) and sebaconitrile (SB)) and LiTFSI salts.
• CLCN acetonitrile
• SN succinonitrile
• SB sebaconitrile
• Electrochemical tests are carried out by galvanostatic cycling at increasing rates (5 cycles at C / 10, C / 5, C / 2, C, 2C and 4C respectively) then at a rate of C, with potential limits set at [ 0.5; 1.5V].
• Figure 5 shows the evolution curves of the specific capacity C (in mAh / g) as a function of the number of cycles N at different speeds.
• the specific capacity remains stable with the number of cycles for the battery using an electrolyte based on acetonitrile, succinonitrile or sebaconitrile.
• the specific capacity is high for the battery using an acetonitrile-based electrolyte. It is lower in the case of the use of succinonitrile or sebaconitrile, due in particular to the strong polarization induced by these viscous electrolytes. It is possible to overcome this drawback and improve the specific capacity of these batteries, via the formulation of a gelled electrode as presented in Example 5 below.
• a PTCDA powder is dispersed with copper nanowires (CuNW) in an 8% solution of polyvinylidene fluoride (PvdF) in N-methylpyrrolidinone in a proportion of 85% PTCDA / 5% CuNW / 10% PvdF (by weight), to which is added 35% by mass of succinonitrile (SN) containing IM LiTFSI, then coated on a copper strip.
• PvdF polyvinylidene fluoride
• N-methylpyrrolidinone N-methylpyrrolidinone
• electrodes After drying at 55 ° C. overnight, electrodes are cut and dried under vacuum for 48 hours.
• Electrodes of 90% LiFeP0 4 , 5% Super P, 5% PvdF compositions are prepared according to the same process.
• Electrodes are assembled in a glove box in a battery using two polyolefin separators, with an electrolyte based on succinonitrile (SN) and LiTFSI salts.
• SN succinonitrile
• LiTFSI salts LiTFSI salts
• the experiment is carried out on three identical batteries.
• Electrochemical tests are carried out in galvanostatic cycling at increasing regimes (C / 10 to 4C) with potential limits set at [0.5; 1.5V].
• Figure 6 shows the evolution curves of the specific capacity C (mAh / g) as a function of the number of cycles, for different cycling regimes (C / 10 to 4C).
• the capacity remains stable whatever the speed (C / 10, C / 5, C / 2, C, 2C and 4C respectively) then during prolonged cycling at a speed of C.
• the gel electrode reduces the polarization of the system and to obtain a higher capacity, in comparison with the capacity obtained in Example 4.

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