Polyamic acid derivative binder for lithium-ion batteries

Abstract

The present invention relates to lithiated polyamic acid derivatives and their use as binders in electrodes for lithium ion batteries.

Description

Cross-reference of related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 003253 filed 3 March 2020 and European Patent Application No. 20172958.9 filed 5 May 2020, the entire contents of this application are incorporated herein by reference for any purpose. [Technical Field]

[0002] This invention relates to lithium polyamic acid derivatives and their use as binders in electrodes for lithium-ion batteries. [Background technology]

[0003] Lithium-ion batteries (LIBs) are used in a variety of portable electronic devices and are being sought after as power sources for hybrid electric vehicles and electric vehicles. To meet the requirements of large-scale applications, LIBs with improved energy density and power capacity are desired.

[0004] The recent trend in lithium batteries is to improve their energy capacity by increasing the amount of lithium stored in the anode. For this reason, conventional graphite anodes, which contain a large amount of silicon, are attracting considerable attention due to their much larger theoretical energy capacity.

[0005] Silicon (Si) is large capacity (at room temperature Li 3.75 Si, 3572mAhg -1 Weight capacity and 8322mAhcm -3 It has a volumetric capacity and a low charge / discharge potential (delithiation voltage of approximately 0.4V). Unfortunately, silicon also has the problem of very large volume changes (>400%) (anisotropic volume expansion) that occur when alloying with lithium ions.

[0006] Changes in volume can lead to various disadvantages. For example, severe pulverization can occur, disrupting the electrical contact between Si particles and the carbon conductive agent. Furthermore, (especially at high current densities) unstable solid electrolyte interfaces (SEIs) can form, resulting in electrode degradation and a rapid decrease in capacity.

[0007] For the reasons mentioned above, electrode formulations for silicon anodes contain a maximum of 20% by weight of silicon compounds, with the remainder being graphite. In particular, electrode formulations containing graphite and silicon compounds ranging from 5% to 20% by weight are being studied.

[0008] Traditionally, all graphite negative electrodes have used polyvinylidene fluoride (PVDF) as a binder. While PVDF interacts well with graphite particles, it does not adhere sufficiently to silicon particles, making the binder susceptible to damage from mechanical stress caused by the expansion and contraction of silicon during charging cycles.

[0009] Recently, there has been a growing trend towards more environmentally conscious approaches that generally avoid the use of organic solvents.

[0010] As an example, aqueous slurries containing carboxymethylcellulose (CMC) and styrene-butadiene rubber (SBR) are known in the art for use as binders. However, CMC / SBR binders are known to be brittle, and fracture points can form in the binder matrix itself. Furthermore, aqueous slurries containing CMC / SBR used as binders have high electrical resistance, resulting in a short lifespan (European Patent No. 2874212).

[0011] Currently, lithium polyacrylate (LiPAA) exhibits the best properties among silicon active materials, but it is brittle and has low toughness. Therefore, when LiPAA is bent into a cylindrical shape, it breaks or cracks, making it only suitable for use in coin batteries.

[0012] When polyimide is used as a binder for the negative electrode, interesting properties can be obtained. Polyimide has excellent mechanical properties, chemical resistance, and heat resistance, but it is insoluble in water and has low initial charge-discharge efficiency.

[0013] Water-soluble polyamic acid may be used as a binder, in which case polyimide can be obtained through a post-treatment imidization process. However, when manufacturing electrodes in this way, oxidation of the copper (Cu) substrate makes it difficult to raise the electrode plate temperature above 160°C, which is necessary for imidization, resulting in a low curing rate of the polyimide binder. A low curing rate causes irreversible reactions because the carboxylic acid groups of the polyamic acid directly bond with lithium ions, resulting in poor initial efficiency. In addition, the presence of unstable amide bonds may negatively affect the battery's lifespan.

[0014] Thus, although polyimide binders possess high adhesive strength and good mechanical and physical properties, they are unsuitable for actual industrial use due to reasons such as difficulty in low-temperature curing leading to unstable bonds and reduced long-term reliability, reduced initial efficiency due to irreversible lithium ion reactions, and insolubility in water.

[0015] One object of the present invention is to provide a polymer binder that can be efficiently used as a binder for silicon anodes. [Overview of the project]

[0016] The present invention provides a binder composition for lithium secondary batteries containing a water-soluble polyamic acid derivative.

[0017] In a first embodiment, the present invention relates to a water-soluble aromatic polyamic acid derivative [polymer (PA)], a) A repeating unit (L) comprising at least 50 mol%, comprising at least one acid moiety in the form of an ester, b) Repeating units (M) in 0 to 50 mol%, comprising at least one acid moiety either as is or in its imide form, c) Repeating units (N) comprising 25-50 mol%, wherein the repeating units (N) include at least one acid moiety as a salt, This relates to water-soluble aromatic polyamic acid derivatives [polymers (PA)] containing such derivatives.

[0018] According to a second aspect of the present invention, the polymer (PA) may be incorporated into an aqueous binder composition (B), the binder composition (B) comprising the polymer (PA) as defined above and at least one aqueous solvent.

[0019] In another embodiment, the present invention is an electrode-forming composition [Composition (C)], (A) The binder composition (B) defined above, (B) At least one electroactive material, (C) Optionally, a thermal initiator and (D) Optionally, an electrical conductivity-imparting additive and This relates to an electrode-forming composition [Composition (C)] containing the following:

[0020] In another embodiment, the present invention relates to the use of an electrode-forming composition (C) for the manufacture of an electrode [electrode (E)], wherein the process is as follows: (i) Prepare a metal substrate having at least one surface, (ii) Prepare the electrode formation composition [Composition (C)] defined above, (iii) Applying the composition (C) prepared in step (ii) onto the at least one surface of the metal substrate prepared in step (i), thereby preparing an assembly comprising the metal substrate coated with the composition (C) on the at least one surface, (iv) Drying the assembly prepared in step (iii), (v) Compressing the dried assembly obtained in step (iv) to obtain the electrode (E) of the present invention, Includes.

[0021] In a further embodiment, the present invention relates to an electrode [electrode (E)] that can be obtained by the process of the present invention.

[0022] For yet another purpose, the present invention relates to an electrochemical device comprising at least one electrode (E) of the present invention. [Modes for carrying out the invention]

[0023] In relation to the present invention, the term “weight percent” (weight%) refers to the content of a particular component in a mixture, calculated as the ratio between the weight of that particular component and the total weight of the mixture. When referring to repeating units derived from certain monomers in a polymer / copolymer, weight percent (weight%) refers to the ratio between the weight of the repeating units of that monomer and the total weight of the polymer / copolymer. When referring to the total solids content (TSC) of a liquid composition, weight percent (weight%) refers to the ratio between the weights of all non-volatile components in the liquid.

[0024] As used herein, "water-soluble" or "soluble in water" means that at least 99% by weight of the polymer (PA) dissolves in deionized water to form a homogeneous solution.

[0025] In this specification, the term "electrochemical device" means an electrochemical cell comprising a positive electrode, a negative electrode, and a liquid electrolyte, wherein a single-layer or multi-layer separator is bonded to at least one surface of one of the electrodes.

[0026] Non-limiting examples of electrochemical devices include, in particular, batteries, preferably secondary batteries and electric double-layer capacitors.

[0027] For the purposes of this invention, the term "secondary battery" is intended to mean a rechargeable battery. Non-limiting examples of secondary batteries include, in particular, alkaline or alkaline earth secondary batteries.

[0028] In this specification, the term "aqueous" is intended to mean a medium containing pure water and water combined with other components that do not substantially alter the physical and chemical properties of water.

[0029] The term “aromatic polyamic acid derivative” is intended to refer to any polymer comprising at least 50 mol% of repeating units comprising an amide moiety and at least one acid moiety in the form of an ester, and at least 25 mol% of repeating units comprising an amide moiety and at least one acid moiety in the form of a salt.

[0030] The repeating unit (L) is preferably selected from the group consisting of any of the units in general formulas (L1) to (L4). [ka] [In the formula, - Ar is a trivalent aromatic moiety selected independently from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms; - Ar' is a tetravalent aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms; - Each R1 is independently H or an alkyl group, preferably H or an alkyl group having 1 to 5 carbon atoms; - R is a divalent aromatic group; preferably, R has the following structure: [ka] and is selected from the group consisting of corresponding optionally substituted structures, where Y is -O-, -S-, -SO2-, -CH2-, -C(O)-, -C(CF3)2-, -(CF2) p -(where "p" is an integer from 0 to 5) and is selected from the group consisting of more preferably, R is

Chemical formula

[0031] The repeating unit (M) is preferably selected from the group consisting of units of any of the general formulas (M1) to (M4).

Chemical formula

[0032] The repeating unit (N) is preferably selected from the group consisting of any of the units in general formulas (N1) to (N4). [ka] In the formula, Ar, Ar', R and R1 are as defined above, and - Cat + is a monovalent cation preferably selected from alkali metal cations, protonated primary, secondary, or tertiary ammonium cations, and quaternary ammonium cations, and more preferably Na + , K+ and Li + Selected from, and more preferably Li + That is the case.

[0033] The trivalent aromatic moiety Ar and the tetravalent aromatic moiety Ar' in the repeating units (L), (M), and (N) defined above may independently have ortho, meta, or para bonds with other moieties.

[0034] Preferably, the polymer (PA) of the present invention is a water-soluble derivative of a polyamic acid containing the following: a) At least 50 mol% of repeating units selected from the group consisting of units of either general formula (L2) or (L4); b) Repeating units selected from the group consisting of units of either general formula (M2) or (M4), in amounts of 0 to 50 mol%; c) Repeating units selected from the group consisting of units of either the general formula (N2) or (N4) in an amount of 25 to 50 mol%.

[0035] In a preferred embodiment of the present invention, the repeating units (N1) to (N4) are Cat + is Li + That is the case.

[0036] Most preferably, the polymer (PA) includes the following: a) At least 50 mol% of repeating units selected from the group consisting of any of the units of general formula (L2); b) Repeating units selected from the group consisting of any of the units of general formula (M2), in an amount of 0 to 50 mol%; c) Repeating units selected from the group consisting of any of the units of general formula (N2) in amounts of 25 to 50 mol%.

[0037] In a particularly preferred embodiment, the repeating unit ( L In ), Z is given by equation O-(CH2) k The group is -O-CO-CH=CHR4, where k is 2 to 6, more preferably 2 or 3; and R4 is H or alkyl, preferably H.

[0038] The relative amounts of repeating units (L1) to (L4), (M1) to (M4), and (N1) to (N4) in the polymer (PA) of the present invention can be measured by any preferred method.

[0039] In particular, the amount of repeating units (M) in the imide form (degree of imidization of the polymer (PA)) can be evaluated by NMR, and the amounts of repeating units (L), (N), and (M) in the acidic form can be evaluated by NMR, elemental analysis, or titration.

[0040] The polymer (PA) can be produced by a process comprising the preparation of a polymer (P-A0) by polycondensation reaction of at least one acid monomer with at least one diamine comonomer containing one or two aromatic rings, followed by partial esterification of the acidic moiety. The obtained partially esterified polymer (P-A0) can then be partially salted out to obtain at least a portion of the acidic moiety in the form of a salt.

[0041] According to the first embodiment, the process for preparing the polymer (P-A0) includes at least the following steps: i) Formula R n R m NR-NRn R m (In the formula, R is as defined above, and each R n and R m This involves preparing at least one diamine comonomer of H or alkyl, preferably H or an alkyl having 1 to 5 carbon atoms; ii) The diamine comonomer prepared in step i) is one of the following compounds (I) to (IV): [ka] (In the formula, Ar and Ar' are as defined above, and X is OH, Cl, Br, F, or I.) The reaction is carried out in the presence of a polar aprotic solvent and an organic base; iii) The polymer obtained in step ii) NR a R b R c -(CH2) k -O-CO-CH=CHR4 (where k and R4 are as defined above), NR a R b R c -(CH2) p -Ar-CR5=CHR6 (where p, Ar, R5, and R6 are as defined above), NR a R b R c -(CH2) q -CH=CHR8 (where q and R8 are as defined above), NR a R b R c -(CH2) r -O-CH=CHR9 (where r and R9 are as defined above) The process involves reacting a compound selected from the group consisting of R a , R b and R c This is independently H or alkyl, preferably an alkyl having 1 to 5 carbon atoms. Includes.

[0042] Among the compounds of formula (IV), trimellitic anhydride monochloride (TMAC) is preferred: [ka]

[0043] Among the compounds of formula (III), pyromellitic dianhydride (PMDA) is preferred. [ka]

[0044] Preferably, the diamine comonomer is selected from the group consisting of 4,4'-diaminodiphenylmethane (MDA), 4,4'-diaminodiphenyl ether (ODA), m-phenylenediamine (MPDA), and combinations thereof. [ka]

[0045] According to one embodiment, the polar aprotic solvent is selected from the group consisting of chlorobenzene, chloroform, N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), 1,3-dimethyl-2-imidazolidinone, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), and sulfolane.

[0046] According to one embodiment, the organic base is selected from the group consisting of pyridine and alkylamines, such as trimethylamine.

[0047] The polymer (PA) can be prepared from the polymer (P-A0) copolymer by at least partially neutralizing the acidic groups with a monovalent cation Cat+, preferably an alkali metal salt, in a suitable solvent.

[0048] The salt may be any alkali metal salt capable of neutralizing the acidic group. In some embodiments, the salt is a lithium salt selected from the group consisting of lithium carbonate, lithium hydroxide, lithium bicarbonate, and combinations thereof, preferably lithium carbonate. In some embodiments, the lithium salt does not contain lithium hydroxide.

[0049] The solvent used in the step of preparing polymer (PA) by salting out polymer (P-A0) may be any solvent that can dissolve the salt and the resulting polymer (PA). Preferably, the solvent is selected from water, NMP, and at least one aqueous solvent such as alcohol, methanol, isopropanol, and ethanol. Preferably, the solvent contains less than 5% by weight, preferably less than 2% by weight, and preferably less than 1% by weight of NMP. More preferably, the solvent does not contain NMP. More preferably, the solvent is an aqueous solvent. Even more preferably, the solvent is water.

[0050] Preferably, the concentration of the salt in the solvent is in the range of 0.5 to 30% by weight, preferably 5 to 30% by weight, and more preferably 10 to 30% by weight, based on the total weight of the solvent and salt.

[0051] In some embodiments where the salt is a lithium salt, the concentration of the lithium salt in the solvent provides at least 0.5 equivalents, 1 equivalent, 1.5 equivalents, 2 equivalents, 2.5 equivalents, 3 equivalents, and 4 equivalents of lithium to the acid group. In some embodiments, the concentration of the lithium salt in the solvent provides up to 5 equivalents, preferably up to 4 equivalents, of lithium to the acid group.

[0052] The polymer (PA) can be isolated as a solid from the solution after salting out and optionally stored for later use. Alternatively, the solid polymer (PA) can be dissolved (or redissolved) in water to prepare the electrode-forming composition described later. However, preferably, the solution containing the polymer (PA) after salting out is an aqueous solution that can be optionally further diluted with water and used directly in the preparation of the binder composition described below.

[0053] In another embodiment, the present invention is an electrode-forming composition [Composition (C)], (A) The binder composition (B) defined above, (B) at least one electroactive compound, (C) Optionally, a thermal initiator and (D) Optionally, an electrical conductivity-imparting additive and This relates to an electrode-forming composition [Composition (C)] containing the following:

[0054] As is well known in the art, an electrode-forming composition is a composition, typically a fluid composition, in which solid components are dissolved or dispersed in a liquid, which is applied to a metal substrate and then dried to form an electrode on which the metal substrate acts as a current collector. An electrode-forming composition typically comprises at least an electroactive material and at least a binder.

[0055] The electrode-forming composition of the present invention [Composition (C)] contains one or more water-soluble aromatic polyamic acid derivatives [polymer (PA)] as defined above, and functions as a binder.

[0056] The preparation of the electrode-forming composition includes the preparation of an aqueous binder composition which is subsequently added together with the powdered electrode material.

[0057] The aqueous binder composition (B) of the present invention can be prepared by dissolving the polymer (PA) in an aqueous solvent, more preferably water.

[0058] To obtain the binder solution (B) described in detail above, it is preferable to dissolve 1 to 15 parts by weight, particularly 5 to 10 parts by weight, of the polymer (P-A) in 100 parts by weight of an aqueous solvent.

[0059] In a preferred embodiment, the binder composition (B) is an aqueous solution containing the polymer (P-A) obtained after partial salting out, which can be directly used for the preparation of the electrode-forming composition and can optionally be further diluted with water for use.

[0060] The electrode-forming composition [composition (C)] of the present invention contains one or more electroactive materials. For the purposes of the present invention, the term "electroactive material" is intended to mean a compound that can incorporate or insert alkali or alkaline earth metal ions into its structure during the charging and discharging stages of an electrochemical device and can then substantially release them. The electroactive material preferably can incorporate or insert lithium ions and release them.

[0061] The nature of the electroactive material in the electrode-forming composition (C) of the present invention differs depending on whether the composition is used for the production of a negative electrode (anode) or a positive electrode (cathode).

[0062] When forming a positive electrode for a lithium-ion secondary battery, the electroactive material may include a lithium-containing compound. In one embodiment, the lithium-containing compound can be a metal chalcogenide of the formula LiMQ2 (where M is at least one metal selected from transition metals such as Co, Ni, Fe, Mn, Cr, and V, and Q is a chalcogen such as O or S). Among these, it is preferable to use a lithium-based metal oxide of the formula LiMO2 (where M is the same as defined above). Preferred examples thereof include LiCoO2, LiNiO2, LiNi x Co 1-x O2 (0 < x < 1) and spinel-structured LiMn2O4 may be mentioned.

[0063] In another embodiment, when forming a positive electrode for a lithium-ion secondary battery, the electroactive material is given by formula M1M2(JO4) f E 1-f The formula may include a lithified or partially lithified transition metal oxyanion-based electroactive material of the form (wherein M1 is lithium, which may be partially substituted by another alkali metal representing less than 20% of the M1 metal; M2 is a transition metal at an oxidation level of +2, selected from Fe, Mn, Ni or a mixture thereof, which may be partially substituted by one or more additional metals at an oxidation level of +1 to +5 and representing less than 35% of the M2 metal; JO4 is any oxyanion where J is any of P, S, V, Si, Nb, Mo or a combination thereof; E is a fluoride, hydroxide, or chloride anion; and f is generally the mole fraction of the JO4 oxyanion contained in 0.75 to 1).

[0064] M1M2(JO4) as defined above f E 1-f The electroactive material is preferably a phosphate-based material and may have a regular or modified olivine structure.

[0065] More preferably, the electroactive material when forming the positive electrode is Li 3-x M' y M'' 2-y The formula (JO4)3 (wherein 0≦x≦3 and 0≦y≦2, M' and M'' are the same or different metals, at least one of which is a transition metal, JO4 is preferably PO4 which may be partially substituted with another oxyanion, and J is any of S, V, Si, Nb, Mo or a combination thereof). More preferably, the electroactive material is of the formula Li(Fe x Mn 1-x The electroactive material is a phosphate system of PO4 (wherein 0 ≤ x ≤ 1, and x is preferably 1 (i.e., lithium iron phosphate of the formula LiFePO4)).

[0066] In another embodiment, the electroactive material for the positive electrode is selected from lithium-containing composite metal oxides of general formula (V). LiRing x M1 y M2 z Y2(V) (In the formula, M1 and M2 are the same or different transition metals selected from Co, Fe, Mn, Cr, and V, 0.5 ≤ x ≤ 1, where y + z = 1 - x, and Y is a chalcogen, preferably a chalcogen selected from O and S.)

[0067] The electroactive material in this embodiment is preferably a compound of formula (I) where Y is O. In a further preferred embodiment, M1 is Mn and M2 is Co, or M1 is Co and M2 is Al.

[0068] An example of such an active material is LiNi x Mn y Co z O2 (hereinafter referred to as NMC in this specification), and LiNi x Co y Al z O2 (hereinafter referred to as NCA in this specification) is one example.

[0069] Specifically, LiNa x Mn y Co z Regarding O2, the power and energy performance of the battery can be adjusted by varying the content ratio of manganese, nickel, and cobalt.

[0070] In a particularly preferred embodiment of the present invention, the electroactive material is a compound of formula (V) defined above (wherein 0.5 ≤ x ≤ 1, 0.1 ≤ y ≤ 0.5, and 0 ≤ z ≤ 0.5).

[0071] Non-limiting examples of suitable electroactive compounds for the positive electrode of formula (I) include, among others: LiRing 0.5 Mn 0.3 Co 0.2 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.8 Co 0.2 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2, LiNi 0.9 Mn 0.05 Co 0.05 O2 include.

[0072] Compound: LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, LiNi 0.8 Mn 0.1 Co 0.1 O2, LiNi 0.9 Mn 0.05 Co 0.05 O2 are particularly preferred.

[0073] When forming a negative electrode for a lithium ion secondary battery, the electroactive material may preferably contain one or more carbon-based materials and / or one or more silicon-based materials.

[0074] In some embodiments, the carbon-based material may be selected from graphite, graphene, or carbon black, such as natural or artificial graphite. These materials may be used alone or in mixtures of two or more thereof.

[0075] The carbon-based material is preferably graphite.

[0076] The silicon-based compound may be one or more selected from the group consisting of chlorosilane, alkoxysilane, aminosilane, fluoroalkylsilane, silicon, silicon chloride, silicon carbide, and silicon oxide.

[0077] More specifically, the silicon-based compound may be silicon oxide or silicon carbide.

[0078] When present in an electroactive material, silicon-based compounds are included in an amount ranging from 1 to 60% by weight, preferably 5 to 20% by weight, relative to the total weight of the electroactive compound.

[0079] According to the present invention, a "thermal initiator" is a substance that uses thermal energy to initiate a radical crosslinking reaction.

[0080] The thermal initiator in composition (C) may be in an amount sufficient to thermally assist the curing of the ethylenically unsaturated component Z of the repeating units (L) of the polymer (PA).

[0081] The concentration of the thermal initiator in composition (C) may be 0.01 to 10% by weight, for example, 0.1 to 5% by weight, 0.2 to 4% by weight, or 0.5 to 3% by weight, based on the total weight of composition (C).

[0082] According to a preferred embodiment of the present invention, the thermal initiator is a low-temperature thermal initiator that can be cured at a temperature not exceeding 130°C.

[0083] Preferably, the thermal initiator is selected from the group consisting of free radical initiators such as peroxides (organic and inorganic peroxides), peroxodisulfate and its salts, peresters and peroxycarbonates, azonitriles and azo derivatives.

[0084] Preferred thermal initiators are selected from the group consisting of the following: - Diacyl peroxides, - Benzoyl peroxide (BPO), - Di-tert-butyl peroxide (DTBP), - Cumene hydroperoxide, - Dicumyl peroxide, - tert-amyl hydroperoxide, - tert-amylperoxybenzoate, - 4,4'-azobis(4-cyanovaleric acid), - 1,1'-azobis(cyclohexanecarbonitride), - 1,1'-azobis(cyclohexanecarbonitride), - Benzoyl peroxide, - 2,2-bis(tert-butylperoxy)butane, - 1,1-Bis(tert-butylperoxy)cyclohexanebenzene, - 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, - 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexine, - Bis(1-(tert-butylperoxy)-1-methylethyl)benzene, - 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, - tert-butyl hydroperoxide, - tert-butyl peracetate, - tert-butyl peroxide, - tert-butylperoxybenzoate, - tert-butylperoxyisopropyl carbonate, - Cumene hydroperoxide, - Cyclohexanone peroxide, - Dicumyl peroxide, - Lauroyl peroxide, - 2,4-pentanedione peroxide, - Potassium persulfate, - 2,2'-Azobis(isobutyronitrile) (AIBN), - Dimethyl 2,2'-azobis(2-methylpropionate), - 2,2'-Azobis[2-(2-imidazolin-2-yl)-propane]dihydrochloride, - 2,2'-Azobis(2-methylbutyronitrile) (AMBN), - 2,2'-Azobis(2,4-dimethyl)valeronitrile, - 2,2'-Azobis(N-butyl-2-methylpropionamide), - 1,1'-azobis(cyclohexane-1-carbonitride), and - 2,2'-Azobis(4-methoxy-2,4-dimethylvaleronitrile).

[0085] According to a preferred embodiment of the present invention, the thermal initiator is a water-soluble thermal initiator that can be dispersed in an aqueous medium. Preferred water-soluble thermal initiators are selected from the group consisting of the following: - 2,2'-Azobis(2-methylpropionamidine)dihydrochloride - 2,2'-Azobis[N-(2-carboxyethyl)-2-methylpropionamidine]tetrahydrate - 2,2'-Azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride - 2,2'-azobis[2-(2-imidazoline-2-yl)propane] - 2,2'-Azobis[2-methyl-N-(2-hydroxyethyl)propionamide] - 4,4'-Azobis(4-cyanovaleric acid) - 1,2-Bis(2-(4,5-dihydro-1H-imidazole-2-yl)propan-2-yl)diazendihydrochloride.

[0086] According to a particularly preferred embodiment of the present invention, the thermal initiator is 1,2-bis(2-(4,5-dihydro-1H-imidazole-2-yl)propan-2-yl)diazendihydrochloride.

[0087] One or more optional conductivity-imparting additives may be added to improve the conductivity of electrodes resulting from the compositions of the present invention. Conductives for batteries are well known in the art.

[0088] Examples of such materials include carbonaceous materials such as carbon black, graphite powder, carbon nanotubes, graphene, or fibers, or fine powders or fibers of metals such as nickel or aluminum. The optional conductive agent is preferably carbon black. Carbon black is available, for example, under the brand names Super P® or Ketjenblack®.

[0089] If present, the conductive agent is different from the carbon-based material described above.

[0090] The amount of the optional conductive agent is preferably 0 to 30% by weight of the total solids in the electrode-forming composition. In particular, for cathode-forming compositions, the optional conductive agent is typically 0% to 10% by weight, more preferably 0% to 5% by weight, of the total solids in the composition.

[0091] For anode-forming compositions that do not contain silicon-based electroactive compounds, the optional conductive agent is typically 0% to 5% by weight, more preferably 0% to 2% by weight, of the total solid content in the composition. On the other hand, for anode-forming compositions that contain silicon-based electroactive compounds, it was found to be beneficial to introduce a larger amount of the optional conductive agent composition, typically 0.5% to 30% by weight of the total solid content in the composition.

[0092] The electrode-forming composition (C) of the present invention can be used in the manufacturing process of an electrode [electrode (E)], and the above process is (i) Prepare a metal substrate having at least one surface; (ii) Prepare the electrode formation composition [Composition (C)] defined above; (iii) Applying the composition (C) prepared in step (ii) onto the at least one surface of the metal substrate prepared in step (i), thereby preparing an assembly comprising the metal substrate coated with the composition (C) on the at least one surface; (iv) Dry the assembly prepared in step (iii); (v) Compressing the dried assembly obtained in step (iv) to obtain the electrode (E) of the present invention; Includes.

[0093] Metal substrates are generally foils, meshes, or nets made of metals such as copper, aluminum, iron, stainless steel, nickel, titanium, or silver.

[0094] In step (iii) of the process of the present invention, the electrode-forming composition (C) is typically applied to at least one surface of a metal substrate by any preferred procedure such as casting, printing, and roll coating.

[0095] Optionally, step (iii) may be repeated typically one or more times by applying the electrode-forming composition (C) prepared in step (ii) onto the assembly prepared in step (iv).

[0096] In step (iv) of the process of the present invention, drying may be carried out under either atmospheric pressure or vacuum. Alternatively, drying may be carried out in a modified atmosphere, such as, for example, under an inert gas, which is typically particularly dehydrated (water vapor content less than 0.001% v / v).

[0097] The drying temperature will be selected to achieve the removal of the aqueous medium from electrode (E) of the present invention by evaporation.

[0098] In step (v), the target porosity and density of the electrode (E) of the present invention can be achieved by subjecting the dried assembly obtained in step (iv) to a compression step such as a calendering process.

[0099] Preferably, the dried assembly obtained in step (iv) is hot-pressed, and the temperature during the compression step is in the range of 25°C to 130°C, preferably about 60°C.

[0100] The preferred target density of electrode (E) is 1.4 to 2 g / cc, preferably at least 1.55 g / cc. The density of electrode (E) is calculated as the sum of the products of the densities of the electrode components multiplied by their mass ratios in the electrode formulation.

[0101] Without wishing to be constrained by any theory, the inventors assume that during drying step (iv), composition (C) applied to at least one surface of the metal substrate hardens.

[0102] In this specification, "curing" means the process by which the ethylenically unsaturated component Z of the repeating units (L) of a polymer (PA) reacts to form an irreversibly crosslinked network (the so-called "cured form") such that the substance no longer flows, melts, or dissolves. Here, the terms "curing," "cured," and "crosslinked" are used interchangeably.

[0103] It is understood that the curing initiated in step (iv) of the process for preparing electrode (E) may be continued during step (v) of the present invention's process for preparing electrode (E).

[0104] The curing of composition (C) of the present invention is carried out at a low temperature to some extent during the drying and / or compression steps (iv) and (v).

[0105] The curing of the polymer (PA) in composition (C) in the electrode (E) of the present invention is determined by Fourier transform infrared spectroscopy (FTIR) at 1000-650 cm⁻¹. -1 This can be verified by measuring the consumption of ethylenically unsaturated components as a result of measuring the change in the peak area of ​​the peak corresponding to the out-of-plane CH bending vibration that occurs during this period.

[0106] Advantageously, the polymer (PA) of the present invention is particularly preferably cured in the presence of a thermal initiator as defined above.

[0107] The applicant of this application is - A polymer (PA) as defined above; - With at least one type of aqueous medium; - With at least one electroactive material; - A thermal initiator, - Optionally, a conductivity-imparting additive and We have surprisingly found that by heat-treating composition (C) containing (for example, during the drying step (iv) and / or the compression step (v)), an electrode (E) product characterized by improved adhesion to a metal current collector can be obtained.

[0108] In a further embodiment, the present invention relates to an electrode [electrode (E)] that can be obtained by the process of the present invention.

[0109] Therefore, the present invention is - Includes a metal substrate having at least one surface, - Adhered directly to at least one surface of the above metal substrate, and at least one layer is A) A water-soluble aromatic polyamic acid derivative [polymer (PA)], a) A repeating unit (L) comprising at least 50 mol%, the repeating unit (L) comprising at least one acid moiety in the form of an ester, b) Repeating units (M) in 0 to 50 mol%, comprising at least one acid moiety either as is or in its imide form, c) Repeating units (N) comprising 25-50 mol%, wherein the repeating units (N) include at least one acidic moiety as a salt, A water-soluble aromatic polyamic acid derivative [polymer (PA)] containing, B) At least one type of electroactive material, C) Optionally, a conductivity-imparting additive and This relates to an electrode (E) comprising a composition containing [a specific substance].

[0110] The composition directly bonded to at least one surface of the metal substrate corresponds to the electrode-forming composition (C) of the present invention, wherein the aqueous solvent of the binder composition (B) is at least partially removed during the electrode manufacturing process, for example in step (iv) (drying) and / or in the compression step (v). Therefore, all preferred embodiments described with respect to the electrode-forming composition (C) of the present invention can also be applied to the composition directly bonded to at least one surface of the metal substrate in the electrode of the present invention, except for the aqueous medium removed during the manufacturing process.

[0111] In a preferred embodiment of the present invention, electrode (E) is a negative electrode. More preferably, the negative electrode contains a silicon-based electroactive material.

[0112] The electrode (E) of the present invention is particularly suitable for use in electrochemical devices, especially in secondary batteries.

[0113] The secondary battery of the present invention is preferably an alkaline secondary battery or an alkaline earth secondary battery.

[0114] The secondary battery of the present invention is more preferably a lithium-ion secondary battery.

[0115] The electrochemical device according to the present invention can be manufactured by standard methods known to those skilled in the art.

[0116] If any disclosure of a patent, patent application, or publication incorporated herein by reference contradicts the description of this application to such an extent that it obscures the terminology, the description herein shall prevail.

[0117] The present invention will be described here with reference to the following examples, but the purpose is merely illustrative and not intended to limit the scope of the invention. [Examples]

[0118] raw materials Silicon dioxide, commercially available as KSC-1064 from Shin-Etsu Chemical Co., Ltd., has a theoretical capacity of approximately 2100 mAh / g; Carbon black, available from Imerys SA as SC45; Graphite, sold commercially by Imerys as ACTILION 2. Carboxymethylcellulose (CMC), commercially available from Nippon Paper Industries Co., Ltd. as MAC 500HC; A styrene-butadiene rubber (SBR) suspension (38% by weight aqueous solution) available from Zeon Corporation as Zeon® BM-480B; Ethylene carbonate:dimethyl carbonate = 1:1 wt% ratio, available from BASF as Selectilyte® LP30; Fluoroethylene carbonate (F1EC) available from Sigma Aldrich; and Vinylene carbonate available from Sigma Aldrich. 1,2-Bis(2-(4,5-dihydro-1H-imidazole-2-yl)propan-2-yl)diazendihydrochloride (hereinafter referred to as the thermal initiator) is available from Sigma Aldrich. Poly(4,4'-oxydiphenylene pyromelitamic acid) (Kapton PolyAmic-Acid) solution (15-16% by weight) in NMP available from Sigma Aldrich Pyromellitic dianhydride (PMDA) available from Sigma Aldrich 4,4'-diaminophenyl ether (ODA) available from Sigma Aldrich Trimethylamine (TEA) available from Sigma Aldrich Anhydrous N-methyl-2-pyrrolidone (NMP) available from Sigma Aldrich Pyromellitic acid diester acrylate / diacid chloride (PADE-HEA-Cl, Mw: 487.24 g / mol), synthesized according to methods reported in the literature. In particular, refer to Hedge et al., "3D Printing All-Aromatic Polyimides using Mask-Projection Stereolithography: Processing the Nonprocessable" (Adv. Mater. 2017, 29).

[0119] General procedure for determining molecular weight (Mn, Mw, Mz, and Mz+1) Molecular weight was measured by gel permeation chromatography (GPC) using N,N-dimethylformamide as the mobile phase. Separation was performed using two 5 μm mixed D columns with guard columns from Agilent Technologies. Chromatograms were obtained using a 254 nm ultraviolet detector. A flow rate of 1.5 ml / min and an injection volume of 20 μL of 0.2 w / v% solution in the mobile phase were selected. Calibration was performed using 12 narrow molecular weight polystyrene standards (peak molecular weight range: 371,000 to 580 g / mol). Number-average molecular weight Mn, weight-average molecular weight Mw, and higher average molecular weights Mz and Mz+1 are reported.

[0120] Preparation 1: Polymer A is prepared according to the synthesis procedure in Scheme 1. [ka] 49.83 g of ODA, 27.26 g of TEA, and 750 mL of anhydrous NMP were added to a 1 L round-bottom flask with a three-neck jacket, equipped with a nitrogen inlet / outlet, thermocouple, and mechanical stirrer. After dissolving the ODA, the solution was cooled to -5.0°C. To this solution, 27.27 g of PMDA and 27.42 g of PADE-HEA-Cl were gradually added over 1.5 hours while maintaining the solution temperature below 0°C. After the addition was complete, 100 mL of anhydrous NMP was added to the mixture and held at 0°C for 3 hours. The solution was then drained into 3 L of water using a Waring blender and allowed to solidify. The precipitated polymer was recovered by vacuum filtration and washed three times with 3 L of methanol. After washing, the powder was dried under reduced pressure (25 in Hg) at 35°C for 48 hours to obtain 119 g of pale yellow powder. The molecular weight of polymer A was calculated. The results are summarized in Table 1.

[0121] Preparation 2: Polymer C One liter (15-16 wt%) of Kapton PolyAmic-Acid solution in NMP was coagulated in three liters of deionized water using a Waring blender. The resulting yellow precipitate was collected by vacuum filtration, washed with two liters of boiling water, and then with two liters of methanol. This yellow powder was dried under reduced pressure (vacuum 25 inHg) at 40°C for five days to obtain 154 g of pale yellow powder. The molecular weight of polymer C was calculated. The results are summarized in Table 1.

[0122] [Table 1]

[0123] Preparation 3: Binder composition containing a lithium-soluble aromatic polyamic acid derivative solution 91 mL of deionized water was added to a flask equipped with a magnetic stirrer. The required amount (1.3 g) of lithium carbonate was added, and the solution was heated to 50°C. While vigorously stirring, 8.3 g of polymer A powder obtained as described above was added. After adding the entire amount of polymer to the flask, heating was continued for 5 days, and a homogeneous solution was taken out at that time. An 8.3 wt% aqueous solution was thus obtained.

[0124] Preparation 4: Binder composition containing a lithified water-soluble aromatic polyamic acid solution 90 mL of deionized water was added to a flask equipped with a magnetic stirrer. The required amount (1.3 g) of lithium carbonate was added, and the solution was heated to 50°C. While vigorously stirring, 9 g of polymer C powder obtained as described above was added. After adding the entire polymer to the flask, heating was continued for 3 days, and a homogeneous solution was removed at that time. A 9% by weight aqueous solution was thus obtained.

[0125] General procedure for preparing electrode-forming compositions and negative electrodes The electrode-forming composition and the negative electrode were prepared using the following apparatus as detailed below: Mechanical mixers: Dispermat® series planetary mixers (speed mixers) and mechanical mixers featuring flat PTFE lightweight dispersion impellers; Film Coater / Doctor Blade: Elcometer® 4340 Motor-Driven / Automatic Film Applicator; Vacuum oven: Vacuum BINDER APT line VD 53; and Roll press: Precision 4-inch hot rolling press / Calendering up to 100℃.

[0126] Example 1: Preparation of a negative electrode containing lithium polymer A An aqueous composition was prepared by mixing 33.13 g of an 8.3 wt% aqueous solution of lithium polymer A obtained in Preparation 3, 14.62 g of deionized water, 10.34 g of silicon dioxide, 41.36 g of graphite, and 0.55 g of carbon black. The mixture was homogenized by gently stirring it in a planetary mixer for 10 minutes, and then mixed again by gently stirring it for 2 hours.

[0127] The electrode-forming composition obtained in this manner was cast onto an 18.5 μm thick copper foil using a doctor blade, and the coating layer was dried in an oven at 60°C for approximately 60 minutes to obtain the negative electrode. The thickness of the dried coating layer was approximately 65 μm. Next, the electrode was hot-pressed at 60°C using a roll press to obtain the target density of 1.6 g / cc. The obtained negative electrode had the following composition: silicon dioxide 18.8 wt%, graphite 75.2 wt%, polymer A 5 wt%, and carbon black 1 wt%.

[0128] Electrode E1 was prepared in this manner.

[0129] Example 2: Preparation of a negative electrode containing lithium polymer A and thermal initiator An aqueous composition was prepared by mixing 33.13 g of an 8.3 wt% aqueous solution of lithium polymer A obtained in Preparation 4, 14.62 g of deionized water, 10.34 g of silicon dioxide, 41.36 g of graphite, 0.55 g of carbon black, and 0.05 g of 1,2-bis(2-(4,5-dihydro-1H-imidazole-2-yl)propan-2-yl)diazendihydrochloride. The mixture was homogenized by gently stirring in a planetary mixer for 10 minutes, and then mixed again by gently stirring for 2 hours.

[0130] The electrode-forming composition obtained in this manner was cast onto a copper foil with a thickness of 18.5 μm using a doctor blade, and the coating layer was dried in an oven at a temperature of 60°C for about 60 minutes to obtain the negative electrode. The thickness of the dried coating layer was approximately 64 μm. Next, the electrode was hot-pressed at 60°C using a roll press to obtain the target density of 1.6 g / cc. The obtained negative electrode had the following composition: silicon dioxide 18.8 wt%, graphite 75.2 wt%, polymer A 5 wt%, and carbon black 1 wt%.

[0131] Electrode E2 was prepared in this manner.

[0132] Comparative Example 1: Anode containing lithium polymer C An aqueous composition was prepared by mixing 30.56 g of a 9% by weight aqueous solution of polymer C obtained in Preparation 2, 17.19 g of deionized water, 10.34 g of silicon dioxide, 41.36 g of graphite, and 0.55 g of carbon black. The mixture was homogenized by gently stirring it in a planetary mixer for 10 minutes, and then mixed again by gently stirring it for 2 hours.

[0133] The binder composition obtained in this manner was cast onto an 18.5 μm thick copper foil using a doctor blade, and the coating layer was dried in an oven at 60°C for approximately 60 minutes to obtain the negative electrode. The thickness of the dried coating layer was approximately 60 μm. Next, the electrode was hot-pressed at 60°C using a roll press to obtain the target density of 1.6 g / cc. The obtained negative electrode had the following composition: 18.8 wt% silicon dioxide, 75.2 wt% graphite, 5 wt% polymer C, and 1 wt% carbon black.

[0134] Electrode CE1 was obtained in this manner.

[0135] Comparative Example 2: Negative electrode containing SBR / CMC An aqueous composition was prepared by mixing 35.0 g of a 2 wt% aqueous solution of CMC, 21.41 g of deionized water, 7.90 g of silicon dioxide, 31.58 g of graphite, and 0.42 g of carbon black.

[0136] The mixture was homogenized by gently stirring it in a planetary mixer for 10 minutes, and then mixed again by gently stirring it for 1 hour.

[0137] After mixing for approximately 1 hour, 3.69 g of SBR suspension was added to the composition and mixed again for 1 hour with low stirring.

[0138] The binder composition obtained in this manner was cast onto a copper foil with a thickness of 18.5 μm using a doctor blade, and the coating layer was dried in an oven at a temperature of 90°C for about 70 minutes to obtain the negative electrode. The thickness of the dried coating layer was approximately 62 μm. Next, the electrode was hot-pressed at 60°C using a roll press to obtain the target density of 1.6 g / cc. The obtained negative electrode had the following composition: silicon dioxide 18.8 wt%, graphite 75.2 wt%, SBR 3 wt%, CMC 2% and carbon black 1 wt%. Electrode CE2 was thus obtained.

[0139] Measurement of the adhesive properties of the negative electrode To evaluate the adhesion of the electrode composition coating on the metal foil, peel tests were performed on electrodes (E1), (E2), (CE1), and (CE2) according to standard ASTM D903 at a speed of 300 mm / min at 20°C.

[0140] The results are shown in Table 1.

[0141] [Table 2]

[0142] Battery manufacturing Lithium coin batteries (CR2032 type, 20 mm in diameter) were prepared in a glove box under an argon gas atmosphere by punching out small electrode discs (12 mm in diameter) manufactured using the compositions of Example 1, Example 2, Comparative Example 1, and Comparative Example 2, with lithium metal as the reference electrode.

[0143] The electrolyte used to prepare the coin cell was a standard 1M LiPF6 solution in EC / DMC at a ratio of 1:1, with F1EC at 10% by weight and VC additive at 2% by weight.

[0144] I used the polyethylene separator (commercially available from Tone Chemical Corporation) in the condition it was received.

[0145] Capacity retention test in half-cells After initial charge and discharge cycles (formation stage) at a low current rate, each cell manufactured as described in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 was cycled at a constant current rate of C / 5-D / 5 with a positive cutoff of 1.5V and a negative cutoff of 0.05V.

[0146] The obtained data is reported in Table 2 below.

[0147] [Table 3]

[0148] The cells prepared in Example 1 and according to the example showed acceptable Coulomb efficiency, good initial capacity, and good retention force after 25 cycles.

[0149] Advantageously, electrodes prepared according to the present invention exhibit a better compromise between adhesion to the current collector and performance within the cell compared to electrodes of the prior art.

Claims

1. A water-soluble aromatic polyamic acid derivative [polymer (P-A)], a) A repeating unit (L) comprising at least 50 mol% of repeating units (L) and at least one acidic moiety in the form of an ester, b) Repeating units (M) in 0 to 50 mol%, comprising at least one acid moiety either as is or in its imide form, c) A repeating unit (N) comprising 25 to 50 mol%, wherein the repeating unit (N) contains at least one acid moiety as a salt, The repeating unit (L) is given by the general formulas (L1) to (L4): 【Chemistry 1】 [In the formula, - Ar is a trivalent aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms, independently of each other; - Ar' is a tetravalent aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms; - Each R １ These are independently H or alkyl, preferably H or an alkyl having 1 to 5 carbon atoms; - R is a divalent aromatic group; preferably, R has the following structure: 【Chemistry 2】 and selected from the group consisting of the corresponding optionally substituted structures, where Y is -O-, -S-, -SO ２ -ien-CH ２ -, -C(O)-, -C(CF ３ ) ２ -, - (CF ２ ) ｐ - Selected from the group consisting of (where "p" is an integer from 0 to 5), More precisely, R is 【Transformation 3】 And, - Each Z is, ・ O-(CH ２ ) ｋ -O-CO-CH=CHR ４ (where k is 1 to 20, preferably 1 to 8, more preferably 2 to 6, and even more preferably equal to 2 or 3, and R ４ is H or alkyl, preferably alkyl having ・O-(CH ２ ) ｐ -Ar-CR ５ =CHR ６ or O-(CH ２ ) ｐ -OAr-CR ５ =CHR ６ (where p is 0 to 20, preferably 1 to 8; Ar comprises one or two aromatic rings or heteroaromatic rings; R ５ and R ６ H, alkyl, preferably alkyl having 1 to 5 carbon atoms, phenyl or COOR ７ (Here, R ７ (is H or alkyl, preferably an alkyl having 1 to 5 carbon atoms); ・O-(CH ２ ) ｑ -CH=CHR ８ (where q is 0 to 20, preferably 1 to 8; and R ８ (wherein H is H or alkyl, preferably an alkyl having 1 to 5 carbon atoms); ・O-(CH ２ ) ｒ -O-CH=CHR ９ (where r is 0 to 20, preferably 1 to 8; and R ９ (This is H or an alkyl group, preferably an alkyl group having 1 to 5 carbon atoms.) [Selected independently from the group consisting of] Selected from a group consisting of any of the following units, The repeating unit (M) is given by the general formulas (M1) to (M4): 【Chemistry 4】 [In the formula, - Ar is a trivalent aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms, independently of each other; - Ar' is a tetravalent aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms; - Each R １ These are independently H or alkyl, preferably H or an alkyl having 1 to 5 carbon atoms; - R is a divalent aromatic group; preferably, R has the following structure: 【Transformation 5】 and selected from the group consisting of the corresponding optionally substituted structures, where Y is -O-, -S-, -SO ２ -ien-CH ２ -, -C(O)-, -C(CF ３ ) ２ -, - (CF ２ ) ｐ - Selected from the group consisting of (where "p" is an integer from 0 to 5), More precisely, R is 【Transformation 6】 is] Selected from a group consisting of any of the following units, The repeating unit (N) is given by the general formulas (N1) to (N4): 【Transformation 7】 [In the formula, - Ar is a trivalent aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms, independently of each other; - Ar' is a tetravalent aromatic moiety selected from the group consisting of substituted or unsubstituted, saturated, unsaturated, or aromatic monocyclic and polycyclic groups having 5 to 50 carbon atoms; - Each R １ These are independently H or alkyl, preferably H or an alkyl having 1 to 5 carbon atoms; - R is a divalent aromatic group; preferably, R has the following structure: 【Transformation 8】 and selected from the group consisting of the corresponding optionally substituted structures, where Y is -O-, -S-, -SO ２ -ien-CH ２ -, -C(O)-, -C(CF ３ ) ２ -, - (CF ２ ) ｐ - Selected from the group consisting of (where "p" is an integer from 0 to 5), More precisely, R is 【Chemistry 9】 And, - Cat ＋ is a monovalent cation, preferably selected from alkali metal cations, protonated primary, secondary, or tertiary ammonium cations, and quaternary ammonium cations, more preferably Na ＋ , K+ and Li ＋ Selected from, more preferably Li ＋ is] A water-soluble aromatic polyamic acid derivative [polymer (P-A)] selected from the group consisting of any of the following units.

2. A water-soluble aromatic polyamic acid derivative [polymer (P-A)] according to claim 1, a) At least 50 mol% of repeating units selected from the group consisting of units of either general formula (L2) or (L4); b) Repeating units selected from the group consisting of either the general formula (M2) or (M4), in an amount of 0 to 50 mol%; c) Repeating units selected from the group consisting of either the general formula (N2) or (N4), in an amount of 25 to 50 mol%, A water-soluble aromatic polyamic acid derivative [polymer (P-A)] containing [the specified substance].

3. An aqueous binder composition (B) comprising the polymer (P-A) according to claim 1 or 2 and at least one aqueous solvent, wherein the aqueous solvent is preferably water.

4. Electrode forming composition [Composition (C)], (i) The binder composition (B) according to claim 3, (ii) at least one electroactive material and (iii) Optionally, a thermal initiator and (iv) Optionally, a conductivity-imparting additive and A composition for electrode formation containing [Composition (C)].

5. The electrode-forming composition [Composition (C)] according to claim 4, wherein the electroactive material comprises one or more carbon-based materials and / or one or more silicon-based materials.

6. The electrode-forming composition [Composition (C)] according to claim 5, wherein the thermal initiator is 1,2-bis(2-(4,5-dihydro-1H-imidazole-2-yl)-propan-2-yl)diazendihydrochloride.

7. An electrode-forming composition [Composition (C)] according to any one of claims 4 to 6, (A) The binder composition (B) described in claim 3, (B) At least one electroactive material selected from one or more carbon-based materials and / or one or more silicon-based materials, (C) A thermal initiator which is 1,2-bis(2-(4,5-dihydro-1H-imidazole-2-yl)-propan-2-yl) diazendihydrochloride, (D) Optionally, an electrical conductivity-imparting additive and A composition for electrode formation containing [Composition (C)].

8. Use of the electrode-forming composition (C) according to any one of claims 4 to 7 for the manufacture of an electrode [electrode (E)], wherein the manufacture is (i) Prepare a metal substrate having at least one surface, (ii) Prepare the electrode forming composition [composition (C)] according to any one of claims 4 to 7, (iii) Applying the composition (C) prepared in step (iii) onto the at least one surface of the metal substrate prepared in step (i), thereby preparing an assembly comprising the metal substrate coated with the composition (C) on the at least one surface, (iv) Drying the assembly prepared in step (iii), (v) Compressing the dried assembly obtained in step (iv) to obtain the electrode (E) of the present invention, The process includes, and includes, the use.

9. An electrode [electrode (E)] that can be obtained by the process described in claim 8.

10. An electrochemical device comprising at least one electrode (E) as described in claim 9.

11. The electrochemical device according to claim 10, wherein the electrochemical device is - Positive electrode and negative electrode It is a secondary battery that includes, An electrochemical device in which at least one of the positive electrode and the negative electrode is the electrode (E) described in claim 9.

12. The electrochemical device according to claim 10, wherein the electrochemical device is - Positive electrode and negative electrode It is a secondary battery that includes, The anode is the electrode (E) described in claim 9, an electrochemical device.

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