CA2763748C

CA2763748C - Process to induce polymerization of an organic electronically conductive polymer

Info

Publication number: CA2763748C
Application number: CA2763748A
Authority: CA
Inventors: Steen Brian Schougaard; Michel Gauthier; David Lepage; Guoxian Liang; Christophe Michot; Christian Kuss
Original assignee: Universite du Quebec a Montreal; Johnson Matthey PLC
Current assignee: Universite du Quebec a Montreal; Johnson Matthey PLC
Priority date: 2009-06-01
Filing date: 2010-06-01
Publication date: 2019-04-02
Anticipated expiration: 2030-06-01
Also published as: JP5659352B2; WO2010139060A1; EP2438105A1; EP2438105A4; CN102449024A; JP2012528899A; KR20120047869A; KR101775492B1; EP2438105B1; CA2763748A1; US8685566B2; CN102449024B; US20120136136A1

Abstract

The invention relates to a process to induce polymerization of an organic electronically conductive polymer in the presence of a partially delithiated alkali metal phosphate which acts as the polymerization initiator.

Description

Process to induce polymerization of an organic electronically conductive polymer Background 1. Technical Field The invention relates to a process to induce polymerization of an organic electronically conductive polymer in the presence of a partially delithiated alkali metal phosphate which acts as the polymerization initiator.

2. Description of the related art Lithium-ion batteries have known a phenomenal technical success and commercial growth since the initial work by Sony in the early 90's based on lithium insertion electrodes, essentially the high voltage cobalt oxide cathode invented by J. B. Goodenough and the carbon anode using coke or graphitized carbonaceous materials.
In the mid 90's, Goodenough (See US 5,910,382 and US 6,391,493) suggested that polyanionic phosphate structures, namely nasicons and olivines, could raise the redox potential of low cost and environmentally compatible transition metals such as Fe, until then associated to a low voltage of insertion. For example LiFePO4 was shown to reversibly insert-deinsert lithium-ion at a voltage of 3.45 V vs a lithium anode corresponding to a two-phase reaction. Furthermore, covalently bounded oxygen atom in the phosphate polyanion eliminates the cathode instability observed in fully charged layered oxides, making an inherently safe lithium-ion battery.
As pointed out by Goodenough (US 5,910,382 & US 6,514,640), one drawback associated with the covalently bonded polyanions in LiFePO4 cathode materials is the low electronic conductivity and limited Li + diffusivity in the material.
Reducing LiFePO4 particles to the nanoscale level was pointed out as one solution to these problems as was the partial supplementation of the iron metal or phosphate polyanions by other metal or anions.
One significant improvement to the problem of low electronic conductivity of complex metal oxide cathode powder and more specifically of metal phosphate was achieved with the use of an organic carbon precursor that is pyrolysed onto the cathode material or its precursor to improve electrical field at the level of the cathode particles [Ravet (US 6,963,666, US 6,855,273, WO 02/027824 and WO 02/027823)].
Preparation of a composite cathode of complex metal oxide with an electronically conductive polymer (ECP) could also overcome low electronic conductivity of complex metal oxide, as demonstrated for example by Wang et al. [An investigation of polypyrrole-LiFePat composite cathode materials for lithium-ion batteries, Electrochimica Acta, 50 (2005) 4649-4654]. Wang disclosed preparation of a LiFePO4-polypyrrole composite cathode by chemically initiating polymerization of pyrrole by FeCl3 in a water dispersion of LiFePO4 and sodium p-toluene-sulfonate as counter-anion. Goodenough et al. also disclosed in WO 06/130766 composite of pyrolytic carbon-coated LiFePO4 (C-LiFePO4) and polypyrrole obtained by electropolymerization of pyrrole.
At industrial scale, electropolymerization is not a convenient process and known chemical routes to prepare LiFePO4-ECP composite are also unsatisfactory.
Problems remain to find a convenient and up-scalable process allowing preparation of surface modified lithium metal phosphate with an electronically conductive polymer.
Summary In view to overcome limitation of known process to prepare surface modified lithium metal phosphate with an electronically conductive polymer, inventors have developed a process to induce polymerization of an organic electronically conductive polymer which is described below.
In accordance with a broad aspect, the invention relates to a process to induce polymerization of an organic electronically conductive polymer in the presence of a partially delithiated alkali metal phosphate of the general formula A1MX04, where A
represents Li, alone or partially replaced by at most 10% as atoms of Na or K, where 0 <x < 1, where M comprises iron and/or manganese, and where X04 represents PO4, alone or partially replaced by at most 10% at. of at least one group selected from SO4 and SiO4, characterized in that the partially delithiated alkali metal phosphate acts as polymerization initiator of unsaturated monomers (or a mixture thereof) which are used as precursor of the electronic conductive polymer.
In accordance with a broad aspect, the invention also relates to convenient routes to obtain such partially delithiated lithium metal phosphate by treatment with selected oxidizers.
In accordance with a specific implementation, the above described process could be applied with lithium metal phosphate and/or carbon-coated lithium metal phosphate. In a specific example of implementation, the carbon-coated lithium metal

3 phosphate may be obtained by pyrolysis of an organic carbon precursor onto the cathode material or its precursors.
In one embodiment, the electronic conductive polymer is at least partially grafted on the surface of the alkali metal phosphate.
These and other aspects and features of the present invention will now become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying drawings.
In accordance with one aspect a method of synthesizing an organic electronically conductive polymer, said method comprising: contacting a partially delithiated alkali metal phosphate of the general formula A1_xMX04 with chemical reactants comprising unsaturated monomers or a mixture of unsaturated monomers;
and initiating with said partially delithiated alkali metal phosphate the polymerization of said unsaturated monomers or mixture of unsaturated monomers to form said organic electronically conductive polymer; wherein: 0 <x < 1; A represents Li, alone or partially replaced by at most 10% as atoms of Na or K; M represents a metal comprising at least 50% as atoms of Fe(II) or Mn(II) or a mixture thereof; X04 represents PO4, alone or partially replaced by at most 10% as atoms of at least one group selected from SO4 and SiO4.
In accordance to a further aspect a composite cathode material, comprising an electronic conductive polymer and a partially delithiated alkali metal phosphate of the general formula A1,MX04, wherein A represents Li, alone or partially replaced by at most 10% as atoms of Na or K, where 0< x < 1, wherein M represents a metal comprising at least 50% as atoms of Fe(ll), or Mn(II), or a mixture thereof, and wherein X04 represents PO4, alone or partially replaced by at most 10% as atoms of at least one group selected from SO4 and SiO4, wherein the electronic conductive polymer is at least partially grafted on the surface of the alkali metal phosphate.
In accordance with a broad aspect a composite material, comprising a partially delithiated alkali metal phosphate comprising a LiNO3 deposit, said partially delithiated alkali metal phosphate being of the general formula A1_xMX04, wherein A
represents

4 Li, alone or partially replaced by at most 10% as atoms of Na or K, where 0< x < 1, wherein M is a metal comprising at least 50% as atoms of iron(II), or manganese (II), or a mixture thereof, and wherein X04 represents PO4, alone or partially replaced by at most 10% as atoms of at least one group selected from and SiO4.
Brief description of the drawings A detailed description of the embodiments of the present invention is provided herein below, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 represents the XRD diagrams (CoKa) of C-LiFePO4 (Life Power P1, available from Phostech Lithium) as received (Curve A), C-FePO4 heterosite obtained by delithiation of C-LiFePO4 (Curve B) and partially delithiated C-LiFePO4 (Curve C) as prepared in example 1.
Figure 2 represents the C/4 galvanostatic cycling curve at 60 C of a battery of the Li/1M LiPF6 EC:DEC 3:7/LiFePO4-PEDOT type. The capacity of the battery (in mAh per g of LiFePO4-PEDOT) is indicated on left ordinate, the coulombic efficiency (coulomb charge/coulomb discharge) on right ordinate, and the number of cycles is shown on the abscissa. The capacity of the LiFePO4-PEDOT cathode obtained during the 1st discharge cycle in slow scan voltametry is 144.5 mAh/g.
Description of Illustrative Embodiments The aim of the present invention is a process to initiate oxidative polymerization of unsaturated monomers by an at least partially delithiated alkali metal phosphate of the general formula A1_xMX04, where A represents Li, alone or partially replaced by at most 10% as atoms of Na or K, where 0< x < 1, where M comprises iron and/or manganese, and where X04 represents PO4, alone or partially replaced by at most 10% at. of at least one group selected from SO4 and SiO4, to form an electrically conductive polymer of a -rr electron conjugated system having p-type doping characteristics. In one embodiment, the electrically conductive polymer is formed at the surface of the alkali metal phosphate.
In a non-limiting example, polymers useful in the present invention, include polymers comprising conjugated regions, or composed entirely, of repeating units which are substituted or unsubstituted aniline, thiophene, pyrrole, phenyl mercaptan, furan, polyaniline, polythiophene, polypyrrole, poly(p-phenylene sulfide), polyfuran and tetrathiafulvalene compound; the same applies to the following cases), -CH20-(CH2CH20)5-CH2CH2-TTF group, -CH20-(CH2CH2)3-S-TTF group, -CH20-(CH2CH20)5-CH2CH2-S-TFT group, and -CH20(CH2)3S03-Na+ group. More specifically, the polythiophene compound includes a polymer compound containing a

5 repeating unit represented by the following formula (III):
In the formula (III), R represents -(CH2)2-, -CH2CH(CH3)-, -CH2CH(C6F113)-, -CH2CH(C10H21)-, -CH2CH(C141-125)-, -CH2CH(phenyI)-, -(CH2)3-, -CH2CH(CH3)CH2-, -(CH2)4-, o-xylene, -CH2CH(OH)-, -CH2CH(CH20-(CH2CH2)3-S-trimethylthiotetrathia-fulvalene)-, -CH2CH(CH20-(CH2CH20)5-CH2CH2-S-trimethylthiotetrathiafulvalene)-, or -CH2CH(CH20(CH2)3S03-Na+)-.
As the electrically conductive polymer of the Tr electron conjugated material formed in the present invention, use may also be made of polymers derived from the oxidative polymerization of: (E)-1,2-bis(2-(3,4-ethylenedioxy)thienyl)vinylene, 1,4-bis(2-(3 ,4-ethylenedioxy)thienyl)benzene, 4,4'-bis(2-(3,4-ethylenedioxy)thienyl)biphenyl, 2,5-bis(2-(3,4-ethylenedioxy)thienyl)furan, 2,5-bis(2-(3,4-ethylenedioxy)thienyl)thiophene, or 2,2':5',2"-ter(3,4-ethylenedioxy)thiophene.
In accordance with a specific implementation, the partially delithiated polymerization initiator of the present invention is a compound corresponding to the general formula A1_xMX0.4 which has an olivine structure, the general formula A1.xMX04 being such that:
- 0 < x < 1 - A represents Li, alone or partially replaced by at most 10% as atoms of Na and/or K;
- M comprise at least 50% at. of Fe(II) or Mn(II) or mixture thereof;
- X04 represents PO4, alone or partially replaced by at most 10 mol% of at least one group chosen from SO4 and SiO4.
In one embodiment, the general formula A1_xMX04 includes 0.02 <x 5_ 0.4.
In a 1st specific embodiment, the polymerization initiator of the present invention is a compound corresponding to the general formula A1MX04 which has an olivine structure, the general formula A1,MX04 being such that:
- 0 < x < 1 - A represents Li, alone or partially replaced by at most 10% as atoms of Na or K;
- M is selected from Fe(ll), Mn(II) and mixture thereof, alone or partially replaced by

6 at most 50% as atoms of one or more other metals selected from Ni and Co and/or by at most 15% as atoms of one or more aliovalent or isovalent metals other than Ni or Co, and/or by at most 5% as atoms of Fe(III), - X04 represents PO4, alone or partially replaced by at most 10 mol% of at least one group chosen from SO4 and Si0.4.
In a 2nd specific embodiment, the polymerization initiator of the present invention is a compound corresponding to the general formula A1_NX0.4 which has an olivine structure, the formula A1_xMX0.4 being such that:
- 0 < x < 1 .. - A represents Li, alone or partially replaced by at most 10% as atoms of Na or K;
- M is selected from Fe(ll), Mn(II) and mixture thereof, alone or partially replaced by at most 50% as atoms of one or more other metals chosen from Ni and Co and/or by at most 15% as atoms of one or more aliovalent or isovalent metals chosen from Mg, Mo, Nb, Ti, Al, Ta, Ge, La, Y, Yb, Cu, Sm, Ce, Hf, Cr, Zr, Bi, Zn, Ca, B
and W and/or by at most 5% as atoms of Fe(III);
- X04 represents PO4, alone or partially replaced by at most 10 mol% of at least one group chosen from SO4 and SiO4.
In a 31-1 specific embodiment, the polymerization initiator of the present invention is a compound corresponding to the general formula Li1_,FeyMn1_yP0.4 which has an olivine structure, wherein 0 <x < 1 and 0 y < 1.
In a 4th specific embodiment, the polymerization initiator of the present invention is a compound corresponding to the general formula Li1_xFeP0.4 which has an olivine structure, wherein 0 < x < 1.
By general formula one means that the stoichiometry of the material can vary by a few percents from stoichiometry due to substitution or other defects present in the structure.
Optionally, the partially delithiated polymerization initiator of the present invention A1_xMX04. which has an olivine structure, may carry on at least a portion of its surface a film of carbon deposited by pyrolysis, denoted C-A1MX04. The deposit of carbon can present a more or less uniform, adherent and non-powdery deposit. It represents up to 15% by weight, preferably from 0.5 to 5% by weight, with respect to the total weight of the material. Synthesis of partially delithiated A1_.MX04 and/or C-A1_xMX04 could be done, without any limitation, by delithiation of AMX04 and/or C-AMX0.4 with chemical oxidizer as described for example by Lemos et al. [A
new insight into the LiFePO4 delithiation process, Solid State Ionics, 177 (2006) 1025], C.M. Julien et al. [Structural and Magnetic Properties of LiFePO4 and Lithium Extraction Effects, Z. Anorg. Allg. Chem., 632 (2006) 1598-1605] or Meng et al.

7 [Intermittent X-Ray diffraction study of kinetics of delithiation in nano-scale LiFePO4, Journal of Power Sources, 189 (2009) 702-705]. Lemos and Julien disclosed, respectively, chemical delithiation of LiM0.03Fe0 97PO4 (M = Cr, Cu, Al or Ti) by use of potassium peroxodisulfate (K2S208) in an aqueous solution, and of LiFePO4 by sodium peroxodisulfate (Na2S208) in an aqueous solution. Meng disclosed chemical delithiation of LiFePO4 by use of NO2BF4 oxidizer in an acetonitrile solution.
Methods to produce AMX04 and/or C-AMX04 compounds are well known. They can be obtained, for example, via a hydrothermal route, via a solid-state thermal route or via a melt route. Deposition of carbon by pyrolysis of an organic carbon precursor could be performed on AMX04 or its precursors.
A large choice of oxidizers is available to perform chemical delithiation, such as, without any limitation, chlorine (Cl2), bromine (Br2), iodine (12), permanganates (for example KMn04), peroxides (for example H202 or Oxonen"), nitronium (for example NO2BF4) or persulfates (for example peroxodisulfate K2S208), the person skill in the art is able to identify suitable oxidizer without undue experimentation and without departing from the present invention.
Chemical delithiation is generally performed in solution, preferably, but without any limitation, in aqueous solution.
Hydrogen peroxide is preferred as oxidizer allowing controlled delithiation in water-based solvent with minimum by-products, optionally in presence of a buffer such as, without any limitation, acetic acid (CH3COOH) to avoid eventual acidification of solution, possibly leading to partial dissolution of lithium metal phosphate and/or C-AMX04.
The inventors also surprisingly discovered that chemical delithiation could be performed efficiently by a gas phase process, for example, a nitrogen oxide gas, especially nitrogen dioxide NO2. For example, exposure of LiFePO4 to NO2 gas allowed preparation of delithiated lithium iron phosphate Li1_xFeP0.4 with 0 <x < 1.
It is why, in another broad aspect, the present invention also relates to the use of gas phase comprising NO2 to perform delithiation of AMXO4 and/or C-AMX04 compounds.
In accordance with a specific implementation, lithium cation extracted from AMX04 and/or C-AMX04 structure during delithiation by NO2 are recovered as lithium nitrate deposited at the surface of AMX04 and/or C-AMX04 as indicated by infrared spectra of delithiated compounds.
It is why, in another broad aspect, the present invention also relates to a

8 composite material of formula A1,MX04 and/or C-A1..MX04 comprising a LiNO3 deposit.
Lithium is assumed to be quantitatively extracted as lithium nitrate.
It is why, in another broad aspect, the present invention also relates to a composite material of formula (LiNO3)x=A1_.11/1X04 and/or (LiNO3)x=C-A1-xMX04.
In accordance with a specific implementation, polymerization is performed by contacting partially delithiated A1..),MX0.4 and/or C-A1_xMX04 with unsaturated monomers, preferably in the presence of at least one salt as source of p-doped conductive polymer counter-anion.
In accordance with a specific implementation, salts preferably comprise an alkali salt (Li, Na or K) and most preferably a lithium salt. Anion of those salts may be selected, without any limitation, among halogenide (F, Cl-, B( or I-), sulfate (S042-), sulfonate (CH3S03-, Tsa, FS03-, CF3S03-, styrene sulfonate, polystyrene sulfonate), acetate (CH3CO2-, CF3CO2-), imide ((CH3S02)2N-, (FS02)2N-, (CF3S02)0), perchlorate (CI04-), borate (BF4-, bis(oxalato)borate anion, difluoro(oxalato)borate anion), and phosphate (PF6-).
In accordance with a specific implementation, polymerization could be performed in a solvent or mixture of solvents, such as, without any limitation, water, alcohol (methanol, ethanol, butanol, propanol, isopropanol), acetonitrile, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, dimethyl sulfoxide. A
person skill in the art is able to identify suitable solvents without undue experimentation and without departing from the present invention.
In accordance with a specific implementation, polymerization could also be performed under exposure of A1.,(MX04 and/or C-A1_xMX04, with a vapor of unsaturated monomers. For vapor phase polymerization A1_xMX04 and/or C-A1_xMX04 is preferably mixed with an alkali salt, preferably a lithium salt, as source of electronically conductive polymer counter-anion.
The amount of electronically conductive polymer polymerized at the surface of A1_xMX04 and/or C-A1,MX04 could be modified depending on parameters such as, without any limitation, delithiation ratio, concentration of monomers, reaction temperature, or solvent. Preferably, it represents up to 20% by weight, preferably from 0.5 to 10% by weight, with respect to the total weight of the material. In the specific implementing case of agglomerates, the electronically conducting polymer could act as both an electronic conductor and a binder to improve cyclability of the material when used as the cathode of a lithium ion battery.
In a specific embodiment, C-A1..xMX04 is in particulate form or agglomerate of nanoscaled particles, and the deposit of carbon on C-A1_xMX04 is deposited on the

9 surface of the particles or inside agglomerate of the nanoscaled particles.
In accordance with a specific implementation, the process of the invention could be performed on A1,MX04 and/or C-A1_xMX04 in the form of primary particles, agglomerates of primary particle, flakes, fibers, thin film deposit, without departing from present invention.
In accordance with a specific implementation, the process of the invention could be performed in presence of additives, such as, without any limitation, surfactant, polymers, carbon particles, carbon fibers, carbon nanotubes, metallic oxides, or metallic powders.
All of the compositions and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure.
While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations can be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.
Example 1: Chemical delithiation of C-LiFePO4 To a dispersion of 6.5 grams of C-LiFePO4 (Life Power P1 available from Phostech Lithium Inc.; Canada) in 250 ml of distilled water under agitation, 250 ml of hydrogen peroxide 30 wt.% in water (available from Sigma-Aldrich; USA) has been added slowly. After 30 min under agitation, partially delithiated C-Li1_xFeP0.4 has been recovered by filtration, washed with water and then dried 24 hours under vacuum at ambient temperature. Atomic absorption analysis of Li + ion in liquid phase determined a C-L10.50FeP0.4 composition. The experiment has been repeated by replacing C-LiFePO4 with C-LiFeo o8Mgo.o2PO4 to obtain C-Li0.63FeomMgo.02PO4.
Example 2: Chemical delithiation of nanosized LiFePO4 6.5 grams of nanosized LiFePO4 (D50= 0.6 pm) produced by a precipitation process as disclosed in US 2007/054187 (provided by Phostech Lithium Inc., Canada) has been treated as in example 1 but with only 30 ml of hydrogen peroxide 30 wt.% in water. Atomic absorption analysis of Li + ion in liquid phase determined a Li F=Pollfil .42- -. -4 composition. The experiment has been repeated by replacing LiFeP0.4 with LiFe07Mn03PO4 to obtain Li0.56Fe0.7M110.3PO4.
Example 3: Chemical delithiation of nanosized LiFePO4 5 2 mL glacial acetic acid (Alfa Aesar) and 5 mL of hydrogen peroxide ACS
Grade, 29.0-32.0% (EMD Chemicals) was added to 100 mL of water. LiFePO4 (10.18 g) (D50 0.6 pm) produced by a precipitation process as disclosed in US 2007/054187 (provided by Phostech Lithium Inc., Canada) was added to the solution. The suspension was vigorously stirred for 15 min. The suspension was

10 subsequently filtered and rinsed with water. The Li1_xFePO4 was dried at 60 C
overnight in a vacuum oven. The solution was analyzed by atomic emission for quantitative determination of the desinsertion of lithium. Results are provided in the following table.
___________________________________________________________________ Product Reactant Quantity Reaction time LiFePO4 10,18g H202 (29-32 %wt) 5.0 mL
Li1_0.3FePO4 15 min.
CH3COOH 2 mL
H20 100 mL
LiFePO4 10.13g H202 (29-32 %wt) 5.0 mL
Li1_0.25FePO4 10 min.
CH3COOH 2 mL
H20 100 mL
LiFePO4 10.0 g H202 __ (29-32 %wt) 2.0 mL

Lii.05FePO4 20 min.
. CH3COOH 5 mL
H20 150 mL
Example 4: Chemical delithiation of nanosized LiFePO4 by gaseous oxidant The set-up consisted of two reaction vessels, connected via plastic tubing and a glass pipe containing anhydrous calcium sulfate. The first reaction vessel was closed air-tight except for the opening to the tube. The vessel, cooled in ice water, contained copper powder and concentrated nitric acid was added drop wise. The produced gas followed the tubing through the calcium sulfate and was then introduced into the second vessel, which was open to the ambient air and which contained 187 mg of C-LiFePO4 Life Power P1. The gas have a characteristic color, therefore it is easy to determine when the vessel is filled. The 110 ml vessel was filled and kept

11 closed for 30 minutes. The sample was removed and characterized by ATR-FTIR
spectroscopy to be approximately completely delithiated.
Similar experiment has been repeated by replacing C-LiFePO4 with nanosized LiFePO4 of example 2. The sample was removed and characterized by ATR-FT1R spectroscopy to be approximately completely delithiated and comprise a deposit of lithium nitrate on its surface.
Similar experiment has been repeated with nanosized LiFePO4 of example 2 while reducing exposure time to 5 min. The sample was removed and characterized to be Li0.59FePO4.
Example 5: Chemical delithiation of nanosized LiFePO4 6.3 grams of nanosized LiFePO4 (D50 0.6 pm) produced by a precipitation process as disclosed in US 2007/054187 (provided by Phostech Lithium Inc., Canada) has been treated with 3.9 grams of iodosobenzene 1,1-diacetate (available from Sigma-Aldrich; USA) in 30 ml of dry acetonitrile. After 24 hours under agitation, partially delithiated Li1_.FePO4 has been recovered by filtration, washed with water and then dried 24 hours under vacuum at ambient temperature. Atomic absorption analysis of Li + ion in liquid phase determined a Lio 7iFePO4 composition. The experiment has been repeated by replacing LiFePO4 with LiFe0,99Nb0.01PO4 to obtain Li0.68Fe0.99Nb0.01PO4.
Example 4: Polymerization of EDOT by delithiated C-LiFePO4 2.37 grams of delithiated C-LiFePO4, produced as in example 1 and 1.75 grams of (CF3S02)2NLi (FluoradTM Lithium HQ-115 available from 3M TM; USA) has been added to 25 ml of methanol, followed by 0.38 gram of 3,4-ethylenedioxythiophene (available from Sigma-Aldrich; USA) dissolved in 15 ml of butanol. The dispersion was heated at 50 C during two days under agitation, before the solvent was eliminated using a rotary evaporator, the resulting powder washed three times with 30 ml of methanol and three times with 30 ml of acetonitrile, and then dried under vacuum at 60 C for 12 hours. The experiment has been repeated with C-L10.63Fe0.9erVig0.02PO4.
Example 5: Polymerization of EDOT by delithiated LiFePO4 4.81 grams of delithiated LiFePO4, produced as in example 2 and 4.95 grams of (CF3S02)2NLi (FluoradTM Lithium HQ-115 available from 3MTm; USA) has been added to 30 ml of methanol/butanol (3:5 vol.), followed by 0.88 gram of 3,4-ethylene-dioxythiophene dissolved in 50 ml of methanol/butanol (3:5 vol.). Dispersion has then

12 been heated at 50 C during one day under agitation, solvent eliminate with a rotary evaporator. The resulting powder was washed three times with 30 ml of methanol and three times with 30 ml acetonitrile, and then dried under vacuum at 60 C for 12 hours.
The experiment has been repeated with Li0.56Fe0.9Mn0.1 PO4. A similar experiment has also been performed by replacing elimination of solvent with rotary evaporator by a spray drying step.
Example 6: Polymerization of EDOT by delithiated LiFePO4 3.10 g LiTFSI (Fluorad Tm Lithium HQ-115 available from 3M; USA) was dissolved in 25 ml of methanol in a Petri dish. After, 0.51 g of 3,4-ethylenedioxy-thiophene (Aldrich) and 4.68 g of Li07FePO4, obtained in example 3, was added to the solution. The Petri dish was placed in an oven at 60 C for 2 hours. A blue color appeared after the evaporation of solvent. The mixture was filtered and rinsed with methanol and acetonitrile. The PEDOT-LiFePO4 (LFP-1) was dried at 60 C
overnight in vacuum oven.
Example 7: Polymerization of EDOT by delithiated LiFePO4 in vapor phase 1.48g LiTFSI (Fluorad Tm Lithium HQ-115 available from 3M; USA) was mixed with 1.5 g of Lia5FePO4, obtained in example 3, and placed in an Erlenmeyer flask.
Subsequently, 0.27 g of 3,4-ethylenedioxythiophene (Aldrich) was added to a small flask. This small flask was placed in the Erlenmeyer flask and vacuum was made. The Erlenmeyer flask was then placed in an oven at 60 C for 2 days. The mixture was filtered and rinsed with methanol and acetonitrile. The PEDOT-LiFePat was dried at 60 C overnight in a vacuum oven (LFP-2).
Example 8: Polymerization of EDOT by delithiated LiFePO4 to form a film 1 .27 g LiTFSI (Fluorad Tm Lithium HQ-115 available from 3M; USA) was mixed with 1.5 g of Li 0,5FePO4, obtained in example 3, 0.24 g 3,4-ethylenedioxy-thiophene and 1.5 mL of methanol. The mixture was coated onto an aluminum sheet and put in an oven for 2 hours at 60 C. The thin film of PEDOT-LiFePO4 was removed from the substrate during rinsing with methanol. The mixture was filtered and rinsed with methanol and acetonitrile. The PEDOT-LiFePO4 film was dried at 60 C
overnight in vacuum oven.
Example 9: Conductivity measurement Electronic conductivity of LFP 1-2 has been obtained by measuring resistance

13 of press pellets, those three powders presents an high electronic conductivity > 0.1 S.cm instead of < 1e S.cm for untreated powders.
Example 10: Polymerization of EDOT on a delithiated cathode A nanosized LiFePO4 as in example 2 and PVdF-HFP copolymer (supplied by Atochem) were carefully mixed in N-methylpyrrolidone in order to obtain a dispersion composed of the LiFePO4/PVdF-HFP 80/20 by weight mixture. The mixture obtained was subsequently deposited, using a Gardner device, on a sheet of aluminum carrying a carbon-treated coating (supplied by Intellicoat) and the film deposited was dried under vacuum at 80 C for 24 hours and then stored in a glovebox.
A 10 cm2 sample (4.3 mg/cm2 loading) of this film was then treated during 10 mn in 20 ml of hydrogen peroxide 30 wt.% in water, washed with water and then dried 24 hours under vacuum at ambient temperature. Film was then placed in a Petri dishes containing 10 ml of methanol/butanol (1:1 vol.), 200 mg of (CF3S02)2NLi (FluoradTM Lithium HQ-115 available from 3M; USA) and 50 mg of 3,4-ethylenedioxy-thiophene. The Petri dish was placed in an oven at 60 C for 2 hours, washed with methanol and acetonitrile, and then dried under vacuum at 60 C for 12 hours (LFP-3).
Example 11: Characterization in batteries Composite cathode electrode was prepared with LFP-1 prepared as in example 6, EBN1010 (product of Superior Graphite) as conductive agent and PVdF-HFP
(product of Arkema) as binder in 80/10/10 wt. proportions. Electrochemical performances of cathode coating were investigated at room temperature in coin cell battery using metallic lithium as anode and 1M LiC104 in EC:DMC (1:1) impregnated in 25 pm polypropylene CelgardTM as electrolyte. Cathode surface was 1.5 cm2 with 3.97 ring/cm2 LFP-1 loading.
A first slow scan voltametry (20 mV/h), between a voltage of 3.0 V and 3.7 V
vs Li /Li was performed at ambient temperature with a VMP2 multichannel potensiostat (product of Bio-Logic-Science Instruments). Power tests were further performed by intentiostatic experiment, rates were calculated from the specific capacity value obtained from first slow scan voltametry (144.5 mAh/g). At 1C discharge capacity is 134 mAh/g and at 10C 112 mAh/g.
The battery was then subjected to C/4 galvanostatic cycling at 60 C. The curve is represented in figure 2.
Another battery has been assembled by using LFP-3 coating obtained in example 10. Slow scan voltametry at ambient temperature determine a 146 mAh/g

14 capacity and subsequent C/4 galvanostatic cycling at 60 C provide a capacity > 140 mAh/g after 50 cycles.
The above description of the embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible within the spirit and scope of the present invention. The scope of the invention is defined in the appended claims and their equivalents.

Claims

Claims:

1. A method of synthesizing an organic electronically conductive polymer, said method comprising:
- contacting a partially delithiated alkali metal phosphate of the general formula A1-x MXO4 with chemical reactants comprising unsaturated monomers or a mixture of unsaturated monomers; and - initiating with said partially delithiated alkali metal phosphate the polymerization of said unsaturated monomers or mixture of unsaturated monomers to form said organic electronically conductive polymer;
wherein:
- 0 < x < 1 - A represents Li, alone or partially replaced by at most 10% as atoms of Na or K;
- M represents a metal comprising at least 50% as atoms of Fe(ll) or Mn(ll) or a mixture thereof;
- XO4 represents PO4, alone or partially replaced by at most 10% as atoms of at least one group selected from SO4 and Sat.

2. The method according to claim 1, wherein M is selected from Fe(ll), Mn(ll) and mixture thereof, alone or partially replaced by (i) at most 50% as atoms of one or more other metals selected from Ni and Co, (ii) at most 15% as atoms of one or more aliovalent or isovalent metals other than Ni or Co, (iii) at most 5% as atoms of Fe(lll), or (iv) any combinations of (i) to (iii).

3. The method according to claim 2, wherein the one or more aliovalent or isovalent metals is selected from Mg, Mo, Nb, Ti, Al, Ta, Ge, La, Y, Yb, Cu, Sm, Ce, Hf, Cr, Zr, Bi, Zn, Ca, B and W.

4. The method according to claim 1, wherein said partially delithiated alkali metal phosphate has the general formula Li1-x FePO4.

5. The method according to claim 1, wherein 0.02 < x <= 0.4.

6. The method according to claim 1, wherein the general formula A1-x MXO4 is Li1-x Fe y Mn1-y PO4 which has an olivine structure and wherein 0 < x < 1 and 0 <= y <= 1.

7. The method according to claim 1, wherein M is at least 90% as atoms of Fe(ll) or Mn(ll) or a mixture thereof.

8. The method according to any one of claims 1 to 7, wherein said partially delithiated alkali metal phosphate includes (i) elementary particles, (ii) agglomerates of particles, or (iii) both (i) and (ii).

9. The method according to any one of claims 1 to 8, wherein said A1-x MXO4 carry on at least a portion of a surface thereof a carbon deposit which is a more or less uniform, adherent and non-powdery deposit.

10. The method according to any one claims 1 to 9, wherein the electronically conductive polymer is at least partially grafted on the surface of said alkali metal phosphate.

11. The method according to any one of claims 1 to 10, wherein said unsaturated monomers comprise substituted or unsubstituted pyrrole, thiophene, aniline or any mixtures thereof.

12. The method according to claim 11, wherein said unsaturated monomers comprise 3,4-ethylenedioxythiophene.

13. The method according to any one of claims 1 to 12, further comprising providing said A1-x MXO4, said providing including performing a partial delithiation of AMXO4.

14. The method according to claim 13, wherein said partial delithiation is performed by an oxidant.

15. The method according to claim 14, wherein said oxidant comprises H2O2, Br2, I2, persulfate, peroxodisulfate or any mixture thereof.

16. The method according to any one of claims 13 to 15, wherein said partial delithiation is performed in aqueous media.

17. The method according to claim 13, wherein said partial delithiation is performed by a gaseous oxidant comprising NO2.

18. The method according to any one of claims 1 to 17, wherein said polymerization is performed in solution.

19. The method according to claim 18, wherein said solution comprises alcohol.

20. The method according to any one of claims 1 to 17, wherein said polymerization is performed in a vapor phase of the monomers.

21. The method according to any one of claims 1 to 17, wherein said polymerization is performed in a gas phase.

22. The method according to any one of claims 18 to 21, wherein said polymerization is performed in presence of an alkali salt.

23. The method according to claim 22, wherein said alkali salt comprises an anion selected from halogenide, sulfate, sulfonate, acetate, imide, perchlorate, borate and phosphate.

24. The method according to claim 22, wherein said alkali salt is a lithium salt.

25. The method according to claim 22, wherein said alkali salt comprise (CF3SO2)2NLi.

26. A composite cathode material, comprising an electronic conductive polymer and a partially delithiated alkali metal phosphate of the general formula A1-x MXO4, wherein A represents Li, alone or partially replaced by at most 10% as atoms of Na or K, where 0 < x < 1, wherein M represents a metal comprising at least 50%

as atoms of Fe(ll), or Mn(II), or a mixture thereof, and wherein XO4 represents PO4, alone or partially replaced by at most 10% as atoms of at least one group selected from SO4 and SiO4, wherein the electronic conductive polymer is at least partially grafted on the surface of the alkali metal phosphate.

27. The composite material according to claim 26, wherein M is selected from Fe(ll), Mn(ll) and mixture thereof, alone or partially replaced by (i) at most 50% as atoms of one or more other metals selected from Ni and Co, (ii) at most 15% as atoms of one or more aliovalent or isovalent metals other than Ni or Co, (iii) at most 5% as atoms of Fe(lll), or (iv) any combinations of (i) to (iii).

28. The composite material according to claim 27, wherein the one or more aliovalent or isovalent metals is selected from Mg, Mo, Nb, Ti, Al, Ta, Ge, La, Y, Yb, Cu, Sm, Ce, Hf, Cr, Zr, Bi, Zn, Ca, B and W.

29. The composite material according to claim 26, wherein M is selected from Fe(ll), Mn(ll) and mixture thereof, partially replaced by (i) at most 50% as atoms of one or more other metals selected from Ni and Co, (ii) at most 15% as atoms of one or more aliovalent or isovalent metals other than Ni or Co, (iii) at most 5%
as atoms of Fe(lll), or (iv) any combinations of (i) to (iii).

30. The composite material according to claim 26, wherein said partially delithiated alkali metal phosphate has the general formula Li1-x FePO4.

31. The composite material according to claim 26, wherein 0.02 < x <=
0.4.

32. The composite material according to claim 26, wherein the general formula A1-x MXO4 is Li1-x Fe y Mn1-y PO4 which has an olivine structure and wherein 0 < x < 1 and 0 <= y <=1.

33. The composite material according to claim 26, wherein M is at least 90% as atoms of Fe(ll) or Mn(ll) or a mixture thereof.

34. The composite material according to any one of claims 26 to 33, wherein said partially delithiated alkali metal phosphate includes (i) elementary particles, (ii) agglomerates of particles, or (iii) both (i) and (ii).

35. The composite material according to any one of claims 26 to 34, wherein A1-xMXO4 carry on at least a portion of a surface thereof a carbon deposit which is a more or less uniform, adherent and non-powdery deposit.

36. The composite material according to any one of claims 26 to 35, wherein said electronically conductive polymer is polymerized at the surface of said partially delithiated alkali metal phosphate in an amount of up to 20% by weight with respect to the total weight of the composite material.

37. The composite material according to claim 36, wherein said amount is of 0.5 to 10% by weight with respect to the total weight of the composite material.

38. A composite material, comprising a partially delithiated alkali metal phosphate comprising a LiNO3 deposit, said partially delithiated alkali metal phosphate being of the general formula A1-xMXO4, wherein A represents Li, alone or partially replaced by at most 10% as atoms of Na or K, where 0 < x < 1, wherein M is a metal comprising at least 50% as atoms of iron(II), or manganese (II), or a mixture thereof, and wherein XO4 represents PO4, alone or partially replaced by at most 10% as atoms of at least one group selected from SO4 and SiO4.

39. The composite material according to claim 38, wherein M is selected from Fe(II), Mn(II) and mixture thereof, alone or partially replaced by (i) at most 50% as atoms of one or more other metals selected from Ni and Co, (ii) at most 15% as atoms of one or more aliovalent or isovalent metals other than Ni or Co, (iii) at most 5% as atoms of Fe(III), or (iv) any combinations of (i) to (iii).

40. The composite material according to claim 39, wherein the one or more aliovalent or isovalent metals is selected from Mg, Mo, Nb, Ti, Al, Ta, Ge, La, Y, Yb, Cu, Sm, Ce, Hf, Cr, Zr, Bi, Zn, Ca, B and W.

41. The composite material according to claim 38, wherein M is selected from Fe(II), Mn(II) and mixture thereof, partially replaced by (i) at most 50% as atoms of one or more other metals selected from Ni and Co, (ii) at most 15% as atoms of one or more aliovalent or isovalent metals other than Ni or Co, (iii) at most 5%
as atoms of Fe(lll), or (iv) any combinations of (i) to (iii).

42. The composite material according to claim 38, wherein said partially delithiated alkali metal phosphate has the general formula Li1-xFePO4.

43. The composite material according to claim 38, wherein 0.02 < x <=
0.4.

44. The composite material according to claim 38, wherein the general formula A1-xMXO4 is Li1-xFeyMn1-yPO4 which has an olivine structure and wherein 0 < x < 1 and 0 <= y <= 1.

45. The composite material according to claim 38, wherein M is a metal comprising at least 90% as atoms of Fe(ll) or Mn(ll) or a mixture thereof.

46. The composite material according to any one of claims 38 to 45, wherein said partially delithiated alkali metal phosphate includes (i) elementary particles, (ii) agglomerates of particles, or (iii) both (i) and (ii).

47. The composite material according to any one of claims 38 to 46, wherein A1-xMXO4 carry on at least a portion of a surface thereof a carbon deposit which is a more or less uniform, adherent and non-powdery deposit.

48. A battery comprising an anode, an electrolyte and a cathode, the cathode including the composite material according to any one of claims 26 to 37.