Polyamidoamine dispersant for electrode materials

Abstract

A dispersant obtained by reacting polyamidoamine C with at least two polyesters P and at least one carboxylic acid or its anhydride or its ester Q; wherein said polyamidoamine C is obtainable from repetitive self-reaction of at least one type of substance B and / or from cross-reaction of at least one B with at least one substance A, wherein the at least one B is an adduct of the at least one substance A and at least one linker D, and B contains 1-15 amine-reactive groups, the at least one substance A is a branched and / or linear aliphatic and / or cycloaliphatic or aromatic polyamine, and the at least one linker D is an acrylate, a maleate / fumarate mono-ester or a maleate / fumarate di-ester, or a mixture thereof. A process for producing a dispersant, a dispersion, an electrochemical device comprising, and use of the dispersant and the dispersion are also provided.

Description

[0001] Polyamidoamine dispersant for electrode materials

[0002] Technical Field

[0003] The invention relates to a dispersant for electrode materials.

[0004] Background art

[0005] Dispersing of active cathode active material is a limiting step toward the efficient production of electrodes of secondary batteries like lithium-ion batteries. The active material needs to be properly dispersed to allow battery performance. An electrode slurry system which is not properly dispersed will have drawbacks such as instability, poor homogeneity, high viscosity. To this end, dispersing additives are used in combination with conductive compounds, binders and solvent to produce a stable slurry. To achieve a higher capacity and energy density it is important that the amount of solvent used is kept to a minimum, consequently increasing the solid content of active material in slurry.

[0006] The dispersing agent needs to be effective at low concentration to avoid reducing the fraction of active material in the overall solid content of the slurry. Other important properties of a dispersing agent are compatibility with slurry components, thermal and electrochemical stability. In particular, the latter needs to be tested to determine whether the additive can be used in determined battery applications which require high voltages.

[0007] WO2021 028519A1 discloses in the examples dispersants based on polyethyleneimine (PEI), s-caprolactone, and lauric acid and with a low acid value of less than 3mg KOH / g. The dispersant is useful to disperse conductive carbon in solvent N-methyl-2-pyrrolidone (NMP) used in battery system. Such PEI dispersant still has the disadvantages of known PEI dispersant such as using highly toxic ethylene imine raw material, and high cost.

[0008] Polyethyleneimine (PEI) has been used in production of high performance pigment dispersants. For example, US20170274335A1 discloses dispersants based on polyamines or polyimines having primary amino groups. Side chains based on two or more poly(oxy-C1 -6-alkylenecarbonyl) compounds (A) and side chains based on alkyl acids (B) are chemically bonded to the polyamines or polyimines. The description specifically disclosed dispersants based on polyethyleneimine (PEI), s- caprolactone, and lauric acid. The dispersants are suitable for organic and inorganic pigments.

[0009] Due to considerations including usage of the highly toxic ethylene imine raw material in production of PEI, non-PEI pigment dispersant was developed to replace PEI altogether with other polyamines such as triethylenetetramine (TETA) and tetraethylenepentamine (TEPA) in the production of dispersants. For example, US2022025193A1 discloses a non-PEI aminic pigment dispersant useful in coating formulation. The pigment dispersant is obtained by reacting amine-rich moieties C with at least one polymer P, said polymer P having one or more amine reactive groups, said amine-rich moieties C are obtainable from repetitive self-reaction of at least one type of substance B and / or from cross-reaction of at least one B with at least one substance A, wherein the at least one B is an adduct of the at least one substance A and at least one linker D, and B contains 1 -15 amine-reactive groups and 4-15 in total number of primary, secondary, tertiary and quatenary amines, and wherein the at least one substance A is a branched and / or linear aliphatic and / or cycloaliphatic or aromatic polyamine containing 4-15 total number of primary, secondary, tertiary and quatenary amines. The adduct C is a polyamidoamine. The description specifically disclosed dispersants based on tetraethylenepentamine (TEPA) as A, polycaprolactone as P, and linker D such as butyl acrylate. The dispersant is a high performance pigment dispersant molecule that can match the performance of PEI-based dispersants.

[0010] Thus, it is desirable and a challenge to develop a new non-PEI dispersant useful in a battery system.

[0011] Summary of the invention

[0012] To solve at least part of the technical problems of the prior art, the invention provides polyamidoamine-based additives which act as a dispersing agent for cathode active materials to be used in the fabrication of electrodes for batteries, e.g. lithium-ion batteries (LiB). The use of such additives increases the dispersibility of cathode active materials, such as NMC (Lithium Nickel Manganese Cobalt Oxide) and LFP (Lithium Iron Phosphate), allowing the production of stable and homogeneous slurries with a lower viscosity. Lowering the slurry viscosity provides advantages also in terms of processing as it requires less solvent, energy and time since the electrode needs to be dried after coating on the current collector.

[0013] The invention provides a polyamidoamine-based additive obtainable from reaction of a polyamidoamine C and at least two polyesters P and at least one carboxylic acid or its anhydride or its ester Q; wherein the polyamidoamine C is obtainable from repetitive self-reaction of at least one type of substance B and / or from cross-reaction of at least one B with at least one substance A; wherein B is an adduct of the at least one substance A and at least one linker D; the at least one substance A is a branched and I or linear aliphatic and I or cycloaliphatic or aromatic polyamine containing 4-15 total number of primary, secondary, tertiary and quaternary amines, and the at least one linker D is an acrylate, a maleate I fumarate mono-ester or a maleate I fumarate di-ester containing 1 -15 amine-reactive groups, or a mixture thereof; wherein the amine-reactive groups in B and D are reacted with reactive amines in B and I or A; and if B has only one amine reactive group, then additional D and I or mixture of B and A is reacted to a previously formed C, wherein such an additional reaction of D and I or mixture of B and A to a formed C is repeated for 1 to 10 times; and wherein said at least two polyesters P each having one or more amine reactive groups.

[0014] Preferably, the amount of polyamidoamine C is 5-50 wt.%, preferably 5-30 wt.%; the amount of polyester P is 30-90 wt.%, preferably 40-90 wt.% and the amount of carboxylic acid or its anhydride or its ester Q is 5-20 wt.%, preferably 5-15 wt.%, based on the total amount of polyamidoamine C, polyester P and carboxylic acid or its anhydride or its ester Q.

[0015] The carboxylic acid is preferably a monocarboxylic acid.

[0016] In this invention, the carboxylic acid ester Q is not a polyester. In other words, the carboxylic acid ester Q does not have repeating units. In some embodiments, the carboxylic acid ester Q is a fatty acid ester. In some embodiments, the acholic part of the carboxylic acid ester Q has 1 to 3 carbon atoms.

[0017] Compared with the pigment dispersant of US2022025193A1 , the polyamidoamine- based additive is obtained from reaction with additional polyester P and at least one monocarboxylic acid or its anhydride or its ester Q. The inventors surprisingly found that such polyamidoamine-based additive has a surprisingly good performance when used as a dispersing agent for dispersing cathode active materials of electrodes for batteries.

[0018] In particular, B is a Michael adduct. In particular, the self-reaction is a selfcondensation. In particular, the cross-reaction is a cross-condensation especially a cross-condensation involving amine and amine-reactive groups.

[0019] The at least two polyesters P of the invention comprise a first polyester and a second polyester.

[0020] In some embodiments, the molecular weight, in particular the number averaged molecular weight, of the first polyester is from 300 to 1500 g / mole, for example, from 300, 400, or 500, to 700, 800, 900, 1000, 1100, 1200, 1300, 1400, or 1500, preferably 500 to 1400 g / mole.

[0021] In some embodiments, the molecular weight, in particular the number averaged molecular weight, of the second polyester is from 1600 to 5000 g / mole, for example, from 1600, 1700, or 1800 to 2900, 3000, 3100, 3200, 3200, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4500, or 5000, preferably from 1600 to 3100 g / mole.

[0022] In some embodiments, the molecular weight, in particular the number averaged molecular weight, difference between the first polyester and the second polyester is at least 300, for example, at least 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, and 1500 g / mole. In some embodiments, the molecular weight, in particular the number averaged molecular weight, difference between the first polyester and the second polyester is below 5000, 4900, 4800, 4700, 4600, 4500, 4400, 4300, 4200, 4100, 4000, 3900, 3800, 3700, 3600, 3500, 3400, 3300, 3200, 3100, or 3000 g / mole.

[0023] In some embodiments, the polyamidoamine C has an amine density of at least 600 mgKOH / g.

[0024] In some embodiments, the polyamidoamine C has an amine density of less than 1000 mgKOH / g. in some embodiments, the invention provides a dispersant obtained by reacting a polyamidoamine C with at least two polyesters P and at least one carboxylic acid or its anhydride or its ester Q; wherein said polyamidoamine C is obtainable from repetitive self-reaction of at least one type of substance B and / or from cross-reaction of at least one B with at least one substance A, wherein the at least one B is an adduct of the at least one substance A and at least one linker D, and B contains 1 -15 amine-reactive groups and 4-15 in total number of primary, secondary, tertiary and quatenary amines, the at least one substance A is a branched and / or linear aliphatic and / or cycloaliphatic or aromatic polyamine containing 4-15 total number of primary, secondary, tertiary and quaternary amines, and the at least one linker D is an acrylate, a maleate / fumarate mono-ester or a maleate / fumarate di-ester containing 1 -15 amine-reactive groups, or a mixture thereof; wherein the amine-reactive groups in B and D are reacted with reactive amines in B and / or A, and if B has only one amine reactive group, then additional D and / or mixture of B and A is reacted to a previously formed C, wherein such additional reaction of D and / or mixture of B and A to a formed C is repeated for 1 to 10 times; and wherein said at least two polyesters P each having one or more amine reactive groups.

[0025] In some embodiments, the polyesters P are polyesters obtainable from ring opening polymerization of lactones and / or lactide, and the polyester has a number averaged molecular weight of 500-20000 g / mole, preferably 500-10000 g / mole, more preferably 500-5000 g / mole. The at least two different polyesters P have different chain lengths. Molecular weights of the polyesters in the invention are determined by size exclusion chromatography based on ASTM D 5296.

[0026] In some embodiments, the carboxylic acid or its anhydride or its ester Q is selected from aliphatic acids, aromatic acids and esters or anhydrides thereof. In some embodiments, the substance A is a polyamine containing 4-15, for example, 4, 5, 6, 7, 8, 9, 10, amines groups, such as tetraethylenepentamine (TEPA).

[0027] In some embodiments, the linker D contains 2-15, for example, 2, 3, 4, 5, 6, 7, 8 amine-reactive groups.

[0028] The polyamidoamine-based additive of the invention is a non-PEI aminic additive. The additive is particularly useful as a dispersant, for example, for dispersing cathode active materials of electrodes for batteries.

[0029] The invention further provides a dispersant, comprising: the polyamidoamine-based additive of the invention.

[0030] The invention further provides use of the dispersant in preparation of an electrode in a battery. The dispersant of the invention is particularly useful to disperse a cathode active material, such as NMC and LFP in an electrode slurry. The electrode slurry typically comprise an electrode active material, a conductive material, a binder, a dispersant, and a solvent (especially an organic solvent). The electrode slurry materials including the electrode active material, conductive material, binder, and solvent may be those conventional in the art. The electrode slurry may optionally further comprise an additional additive selected from one or more of adhesion promoters, wetting agents, and corrosion inhibitors.

[0031] The solvent for preparation of an electrode slurry may be polar or non-polar. The solvent may be an organic solvent or an inorganic solvent. The solvent is preferably selected one or more from NMP, dimethyl sulfoxide (DMSO), and dihydrolevoglucosenone (Cyrene), which are particularly useful in battery systems.

[0032] The invention further provides use of the dispersant according to the invention to disperse a particulate, especially a particulate selected from particulate electrode materials, carbon or carbon-coated particles in a solvent, especially an organic solvent.

[0033] The invention further provides a dispersion comprising a continuous phase, a particulate to be dispersed (i.e. , a dispersed particulate) and a dispersant according to the invention or the dispersant prepared according to the method of the invention. The dispersed particulate is preferably cathode active materials, such as NMC and LFP. The continuous phase typically comprises a solvent, especially an organic solvent.

[0034] The solvent may be solvent for preparation of an electrode slurry as mentioned above. For other applications, the continuous phase solvent may also be selected from alcohols (in particular methanol, ethanol and terpineol), hydrocarbons (in particular toluene), and ketones (in particular methyl ethyl ketone). The amount of the dispersed particulate is preferably between 0.1 wt.% and 99.9 wt.%, more preferably between 0.5 wt.% and 99 wt.%, and most preferably between 1 wt.% and 95 wt.%, based on the total weight of the dispersion. As the amount of dispersed particulate by weight % in the overall dispersion depends largely on the density of the dispersed particulate, in dispersions useful for battery systems, the dispersion may suitably comprise between 1 wt.% to 19.9 wt.% conductive carbon, preferably between 5 wt.% to 18 wt.% and most preferably between 7 wt.% to 15 wt.%. Additionally, the dispersion may comprise 60 wt.% to 80 wt.% lithium containing material. As such, for battery system applications the dispersion may preferably comprise a total amount of dispersed particulate between 60 wt.% and 99.9 wt.%, for example, 70-99 wt.% of the dispersion.

[0035] The invention further provides an electrochemical device comprising the dispersant or the dispersion according to the invention.

[0036] The electrochemical device encompasses all kinds of devices that undergo electrochemical reactions. Examples of the electrochemical device include all kinds of primary batteries, secondary batteries, fuel cells, solar cells, capacitors and the like, preferably secondary batteries.

[0037] Generally, the secondary battery is fabricated by inclusion of the electrolyte in an electrode assembly composed of a cathode and an anode, which are faced opposite to each other with (or without for solid electrolyte) a separator therebetween.

[0038] The secondary batteries are preferably lithium ion batteries.

[0039] The invention further provides a battery comprising a dispersant or dispersion according to the invention.

[0040] The invention further provides use of the dispersion according to the invention in preparation of an electrochemical device including batteries.

[0041] According to the invention, the dispersant of the invention has side chains based on two or more poly(oxy-Ci-6-alkylenecarbonyl) compounds. These side chains are also called POAC side chains hereinafter.

[0042] In some embodiments, the at least two different polyesters P are based on two or more poly(oxy-Ci-6-alkylenecarbonyl) compounds.

[0043] In some embodiments, the poly(oxy-Ci-6-alkylenecarbonyl) compounds are homopolymers but have different chain lengths. Preferably, the poly(oxy-Ci-6- alkylenecarbonyl) compounds are poly(oxy-C4-6-alkylenecarbonyl) compounds.

[0044] In some embodiments, the poly(oxy-Ci-6-alkylenecarbonyl) compounds are selected from the group of linear hydroxy-Ci-6-alkylenecarboxylic acids and lactones. In some embodiments, the poly(oxy-Ci-6-alkylenecarbonyl) compounds are 5- valerolactone or s-caprolactone.

[0045] In some embodiments, the carboxylic acid Q is selected from the group of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid.

[0046] The invention further provides a dispersant based on polyamidoamines, wherein the dispersant has the formula (I): Formula (I) in which

[0047] X-*-*-*-X is a polyamidoamine, each comprising primary and / or secondary amino groups, are POAC side chains which are side chains based on poly(oxy-Ci-6- alkylenecarbonyl) compounds, with T = a saturated or unsaturated alkyl group,

[0048] V = an -Ci-6-alkylene group, each of m, n, r and t is an average number, m and n = each 3 to 40, where m and n are different from one another, preferably, the difference between m and n is from 3 to 35, especially from 5 to 20, r and t = each 1 to 100, and

[0049] Z are side chains based on carboxylic acids or anhydrides or esters thereof Q with s = 1 to 100, preferably the carboxylic acid is selected from the group consisting of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid.

[0050] It is also preferable that m and n is not less than 3 and more preferably not less than 5. Preferably, n is not greater than 40, preferably not greater than 30 and more preferably not greater than 15.

[0051] The chain length of the poly(oxy-Ci-6-alkylenecarbonyl) compounds for formation of the POAC side chains on the polyamidoamine is represented by the number of repeat units of the [-O-V-CO-] unit.

[0052] The dispersant may preferably have 3 to 40 repeat units per polyester chain. Preferably, the chain length of the poly(oxy-Ci-6-alkylenecarbonyl) compounds is not more than 30 and more preferably not more than 15 repeat units.

[0053] Preferably, r, s and t are not less than 1 and more preferably not less than 3.

[0054] It is also preferable that r, s and t are not greater than 100 and more preferably not greater than 60.

[0055] In some embodiments, the poly(oxy-Ci-6-alkylenecarbonyl) compounds are polymerized from linear hydroxy-Ci-6-alkylenecarboxylic acids or lactones.

[0056] In some embodiments, the poly(oxy-Ci-6-alkylenecarbonyl) compounds are polymerized from 5-valerolactone or s-caprolactone.

[0057] The invention further provides a method for preparing a dispersant, preferably the dispersant of the invention, preferably comprises the reaction of a polyamidoamine C with at least two or more polyesters P based on poly(oxy-Ci-6-alkylenecarbonyl) compounds according to with T = a saturated or unsaturated alkyl group,

[0058] V = an -Ci-6-alkylene group, each of m, n, r and t is an average number, m and n = each 3 to 40, where m and n are different from one another, preferably, the difference between m and n is from 3 to 35, especially from 5 to 20 r and t = each 1 to 100, and carboxylic acids or anhydrides or esters thereof Q, wherein an amidation of carboxylic acids or anhydrides or esters thereof Q with the polyamidoamine C takes place, preferably the carboxylic acid is selected from the group consisting of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid, Preferably wherein an amidation of carboxylic acids or anhydrides or esters thereof Q with the polyamidoamine C takes place.

[0059] In some embodiments, the molar ratio of the sum total of poly(oxy-Ci-6- alkylenecarbonyl) compounds and alkyl acids or esters thereof to primary and / or secondary amino groups of the polyamidoamine is less than 1 .

[0060] In some embodiments, the molar ratio of the sum total of poly(oxy-Ci-6- alkylenecarbonyl) compounds and alkyl acids or esters thereof to primary and / or secondary amino groups of the polyamidoamine is less than 0.9.

[0061] In some embodiments, the molar ratio between the two or more different poly(oxy- Ci-6-alkylenecarbonyl) compounds and the alkyl acids or esters thereof is between 90 / 10 and 10 / 90.

[0062] In some embodiments, molar ratio between the two or more different poly(oxy-Ci-6- alkylenecarbonyl) chains and the carboxylic acids or anhydrides or esters thereof is between 80 / 20 and 20 / 80.

[0063] In some embodiments, the molar ratio between the two or more different poly(oxy- Ci-6-alkylenecarbonyl) chains and the carboxylic acids or anhydrides or esters thereof is between 70 / 30 and 30 / 70.

[0064] In some embodiments, the polyesters P are prepared separately or in situ by polymerization of the poly(oxy-Ci-6-alkylenecarbonyl) compounds and then used for the reaction with polyamidoamine and alkyl acids or esters thereof.

[0065] In some embodiments, the poly(oxy-Ci-6-alkylenecarbonyl) compounds are polymerized from linear hydroxy-Ci-6-alkylenecarboxylic acids or lactones.

[0066] In some embodiments, the poly(oxy-Ci-6-alkylenecarbonyl) compounds are polymerized from 5-valerolactone or s-caprolactone.

[0067] In some embodiments, the poly(oxy-Ci-6-alkylenecarbonyl) compounds are homopolymers having different chain lengths. In some embodiments, the repeating unit number difference between the longest chain and the shortest chain of the different polyester P is at least 3, for example, at least 4, 5, 6, 7, 8, 9, 10, etc.

[0068] In some embodiments, the chain length difference between the longest chain and the shortest chain of the at least two different poly(oxy-Ci-6-alkylenecarbonyl) compounds is at least 3, for example, at least 4, 5, 6, 7, 8, 9, and 10, etc.

[0069] In some embodiments, the molecular weight, in particular the number averaged molecular weight, difference between the longest chain and shortest chain of the different poly(oxy-Ci-6-alkylenecarbonyl) compounds is at least 300, for example, at least 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, and 1500, etc.

[0070] The term “amine-reactive group” describes a functional group that can react with an amine. Amine reactive groups are preferably acid groups, ester groups, ketone groups, aldehyde groups, epoxy groups, isocyanate groups, uretdiones groups, carbodiimide groups, Michael acceptors or anhydride groups. Michael acceptors are substances with ethylenic or acetylenic moieties that are next to electron withdrawing group such as ketone, ester or nitrile. Most preferred amine reactive groups are ester groups or Michael acceptors.

[0071] The term “reactive amines” means primary or secondary amines. It is preferred that B and / or A comprises each at least one primary or secondary amine out of the 4-15 in total number of primary, secondary, tertiary and quaternary amines. More preferably B comprises at least one primary or secondary amine and A comprises at least two primary or secondary amines. Most preferably B comprises at least four primary or secondary amines and A comprises at least four primary or secondary amines.

[0072] Polyamine A is preferably smaller than 600 g / mole, more preferably smaller than 500 g / mole and most preferably smaller than 300 g / mole and it preferably contains 4-15 primary and / or secondary amines.

[0073] It is preferred that the amine-reactive groups in B and D are substantially reacted with reactive amines in B and / or A meaning these groups are reacted so that the structure of C can be built up, more preferably it means these groups are reacted close to 100 % or most preferably fully reacted with primary and / or secondary amines.

[0074] In case adduct B has only one amine reactive group the proviso applies to react additional D and / or mixture of B and A for 1 to 10 times to a previously formed C. Adduct B has only one amine reactive group if linker D is an acrylate. If adduct B has more than one amine reactive group, the additional reaction of D and / or mixture of B and A to a formed C for 1 to 10 times is optional. Adduct B can be an intermediate that is formed by reacting linker D and substance A which then self-reacts or reacts with remaining substance A to form polyamidoamine C or adduct B can be formed first in a reaction of D and A and in a separate step is self-reacted and / or reacted with A to form polyamidoamine C.

[0075] Linker D being an acrylate, maleate / fumarate mono-ester or maleate / fumarate diester containing 1 -15 amine-reactive groups or a mixture thereof. Preferably linker D is maleate / fumarate di-ester containing 1 -15 amine-reactive groups. In another preferred embodiment linker D contains one or more Michael acceptor and one or more carboxylic acid and / or carboxylate ester and / or anhydride moieties

[0076] The molar ratio between polyamine A and linker D dictates the size of resultant polyamidoamine. Bearing in mind the multifunctionality of both polyamine and linker, the ratio of polyamine A and linker D should be kept at a level that gives optimum size build-up without gelation. However, with increased amount of linker used, the amine density of the resultant adduct B (polyamidoamine) becomes lesser. The amine values of such reaction products are typically lower than PEI of which the extent will depend on the ratio of polyamine to linker.

[0077] A dispersant obtained from polyamidoamine C having an amine density of 600 mg KOH / g to 1 ,000 mg KOH / g is thus preferred.

[0078] More preferred is a dispersant, characterized in that the polyamidoamine C having an amine density of 700 mg KOH / g to 1 ,000 mg KOH / g and most preferred is an amine density of 700 mg KOH / g to 900 mg KOH / g.

[0079] The molecular weight of polyester P preferably lies between 1 ,000 g / mole and 10,000 g / mole. The number of amine reactive groups in polyester P preferably ranges from 1 - 100, more preferably from 10 to 100.

[0080] Polyester P having amine reactive groups is preferably a polylactone or polycaprolactone.

[0081] In another preferred embodiment of the invention the dispersant is characterized in that adduct B has 2 to 15 amine-reactive groups and additional D and / or mixture of B and A is reacted to a previously formed C, such additional reaction of D and / or mixture of B and A to a formed C is repeated for 1 to 10 times.

[0082] Polyamine A is preferably selected from the group consisting of triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

[0083] The incorporation of Q serves to binder interacting moieties to the dispersant molecules. Substance Q is a non-polymeric molecule selected from the group consisting of carboxylic acid, carboxylic ester, or anhydride. Substance Q is preferably a carboxylic acid. The carboxylic acid may preferably be selected from the group consisting of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid.

[0084] The present invention also pertains to a process for producing a dispersant comprising the steps of a) repetitive self-reaction of at least one type of substance B and / or cross-reaction of at least one B with at least one A to produce polyamidoamines C having an amine density of at least 600 mg KOH / g, with

[0085] B being an adduct of at least one substance A and at least one linker D and B containing 1 -15 amine-reactive groups and 4-15 in total number of primary, secondary, tertiary and quaternary amines, substance A being a branched and / or linear aliphatic and / or cycloaliphatic or aromatic polyamine containing 4-15 total number of primary, secondary, tertiary and quaternary amines, linker D being an acrylate, maleate / fumarate mono-ester or maleate / fumarate diester containing 1 -15 amine-reactive groups, or a mixture thereof; the amine-reactive groups in B and D are reacted with reactive amines in B and / or A and if B has only one amine reactive group then additional D and / or mixture of B and A is reacted to a previously formed C, such additional reaction of D and / or mixture of B and A to a formed C is repeated for 1 to 10 times; and b) reacting the polyamidoamines C with at least two polyesters P each having one or more amine reactive groups together with substance Q, wherein substance Q is a non-polymeric molecule selected from the group consisting of carboxylic acid, carboxylic ester, or carboxylic anhydride.

[0086] It is preferred in the process for producing a dispersant that polyamidoamines C have an amine density of 600 mg KOH / g to 1 ,000 mg KOH / g.

[0087] It is further preferred in the process for producing a dispersant that polyester P is a polylactone or polycaprolactone.

[0088] It is further preferred in the process for producing a dispersant that substance Q is a non-polymeric molecule selected from the group consisting of carboxylic acid, carboxylic ester, or anhydride. Substance Q is preferably a carboxylic acid.

[0089] In another preferred embodiment of the inventive process for producing a dispersant, adduct B has 2 to 15 amine-reactive groups and additional D and / or mixture of B and A is reacted to a previously formed C, such additional reaction of D and / or mixture of B and A to a formed C is repeated for 1 to 10 times.

[0090] In yet another preferred embodiment of the process for producing a dispersant, polyamine A is selected from the group consisting of triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine. The invention provides chemical compounds capable to disperse cathode active materials which can be formulated in a stable dispersion. The improved dispersion is proven by a decrease of slurry viscosity. No detrimental effects in terms of coating and electrochemical stability are brought by the additive presence in the slurry composition.

[0091] Cathode active material

[0092] Examples of the cathode active materials that can be used in the present invention may include, but are not limited to, layered compounds such as lithium cobalt oxide (LiCoC ) and lithium nickel oxide (LiNiC>2), or compounds substituted with one or more transition metals; lithium manganese oxides such as compounds of Formula Lii+xMn2-xO4 (0^x^0.33), LiMnOs, LiMn2O3 and LiMnC ; lithium copper oxide (Li2CuO2); vanadium oxides such as LiVsOs, V2Os and CU2V2O7; Ni-site type lithium nickel oxides of Formula LiNii-xMxO2 (M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, and 0.01 ^x^O.3); LiMPCM (M=Fe, Mn, Co, Ni); lithium manganese iron phosphate (LMFP, LiMnxFei-xPO4, such as LiMno.6Feo.4PO4, LiMno.sFeo.2PO4); lithium manganese composite oxides of Formula LiMn2-xMxO2 (M=Co, Ni, Fe, Cr, Zn or Ta, and 0.01 ^x^0.1 ), or Formula Li2Mn3MOs (M=Fe, Co, Ni, Cu or Zn); LiMn2O4 wherein a portion of Li is substituted with alkaline earth metal ions; disulfide compounds; and Fe2(MoO4)3, LiFesO4, etc.

[0093] In some embodiments, the cathode active material is selected from:

[0094] NMC (NCM) or Lithium Nickel Cobalt Manganese Oxide (LiNiCoMnO2),

[0095] LFP or Lithium Iron Phosphate (LiFePO4 / C),

[0096] LMFP, or Lithium Manganese Iron Phosphate (olivine LiMnxFei-xPO4 / C),

[0097] LNMO or Lithium Nickel Manganese Spinel (LiNio.5Mm.5O4),

[0098] NCA or Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAIO2),

[0099] LMO or Lithium Manganese Oxide (LiMn2O4), and

[0100] LCO or Lithium Cobalt Oxide (LiCoO2).

[0101] In some embodiments, the cathode active material is selected from LiFePO4, LMFP, LiCoO2, LiNio.sMno.1Coo.1O2, LiNio.6Mno.2Coo.2O2, and LiNi0.s5Co0.05AI0.1O2.

[0102] The binder is a component assisting in binding between the active material and conductive material, and in binding with the current collector. The binder is typically added in an amount of 1 to 50% by weight, based on the total weight of the mixture including the cathode active material. Examples of the binder may include polyvinylidene fluoride (PVDF), polyvinyl alcohols, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinyl pyrollidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber (SBR), fluoro rubber and various copolymers. The cathode is, for example, fabricated by applying a mixture of a cathode active material, a conductive material and a binder to a cathode current collector, followed by drying and pressing. If necessary, a filler may be further added to the above mixture.

[0103] Advantages brought by the invention include: a. Improved dispersion of cathode active material; b. providing a better and alternative dispersant for electrode material, replacing conventional dispersants such as polyvinylpyrrolidone (PVP); c. Increased solid content of the solvent-based suspension (slurry); d. reduced processing time and energy consumption to produce electrodes; and e. savings on solvent usage, recycling and purification.

[0104] Other advantages of the present invention would be apparent for a person skilled in the art upon reading the specification.

[0105] Detailed description of the invention

[0106] The invention is now described in detail by the following examples. The scope of the invention should not be limited to the embodiments of the examples.

[0107] Procedures

[0108] In the examples, the following protocols were followed.

[0109] Viscosity measurement

[0110] The dynamic viscosity of the slurries was determined by plate-plate geometry on an Anton Paar rheometer (MCR 302). For this purpose, the shear rate was gradually increased from 0.1 1 / s to 300 1 / s in logarithmic steps. Subsequently, the shear rate was reduced again to 0.1 1 / s in the same steps. The plate was kept constant at room temperature (23°C).

[0111] Coating and calendaring

[0112] With the use of the mini tape casting coater from MTI Corp, the slurries were cast into foils. For this purpose, an aluminum foil with a thickness of 16 pm was used as a substrate and placed on the tape caster in a size of about 100 x 180 mm. By means of a vacuum function, the aluminum foil was pulled onto the plate of the tape caster so that it rested without defects. Subsequently, a doctor blade, whose gap height was adjusted to the slurry, was placed on the aluminum foil in which the slurry was placed. With a travel speed of about 3 mm / s, the aluminum foil was coated with the slurry. The coated film was then baked out in a drying oven at 120 °C for at least 20 minutes. In order to best bake out the cathode foil, it was finally dried for about 12 h in a vacuum drying oven at 120 °C and about 100 mbar.

[0113] To increase the density of the cathode, it was compacted by using a calendar from the company Sumet. The pressure of the rollers was kept constant at 300 N / mm and the temperature of the rollers at 40 °C. The roll spacing of the upper and lower rollers had been adjusted depending on the starting and target cathode height. 2.5 cm wide strips were cut out of the coated cathode foil, which were calendared individually and consecutively once. As a guideline, a target density of 3.4 g / cm3for NMC-based cathode films was assumed. Subsequently, cathodes with a diameter of 12.7 mm were punched out, which were used for the construction for button cells. In order to determine the final density and the capacity of the cathodes, the mass of the punched cathodes was determined. The punched cathodes were then dried again in a vacuum drying oven for at least 3 h before they were stored in a glovebox under argon atmosphere.

[0114] Cell building and testing

[0115] The cathodes developed were tested in coin cells for their electrochemical properties. For this purpose, coin cells in CR2032 format were created. All cells were built in a glovebox under argon atmosphere. A steel spacer was inserted into the anode shell, on which the anode was placed. If a full cell was built, an commercial anode of the MTI Corp, (single sided bc-cf-241 -ss-005) with a diameter of 14 mm was used. For half cells, a lithium anode with a diameter of 15.6 mm and a thickness of 0.25 mm was used. A previously punched separator (Celgard 2500) with a diameter of 16 mm was placed on the anode. Then 50 pl electrolyte (1 M LiPF6 in EC / EMC 50:50) were added and checked whether the separator was well wetted. The cathode, which had a diameter of 12.7 mm, was placed on the separator impregnated with electrolyte. Before the cell was closed, another spacer and spring were placed on the cathode to improve contacting. With a crimper and a pressure of 0.8 T, the coin cell was then closed and sealed in such a way that no air could enter the interior of the coin cell.

[0116] The electrochemical measurements of the coin cell were carried out on the battery cyclist of Maccor (Maccor 4000) or Biologic (MPG-200). Here, the specific capacity (out of the discharge capacity) of the batteries was determined as a function of the C-rate by measuring the C-rates 0.1 C, 0.2C, 0.5C and 1 C in each 5 cycles within 2.5 V and 3.8 V in a CCCVDC program. Subsequently, the batteries were further measured over several cycles at 0.1 C.

[0117] Materials

[0118] In the examples, the following materials were used:

[0119] Carbon black: Super P Conductive, commercially available from Alfa Aesar (CAS 1333-86-4)

[0120] NMC: NMC 622, commercially available from MSE Supplies (CAS 346417-97-8) LFP: DY-1 , commercially available from Shenzhen Dynanonic Co., Ltd., China PVDF: Kynar® HSV 1810 and HSV 900, commercially available from Arkema PVP: Polyvinylpyrrolidone K30 commercially available from Sigma Aldrich

[0121] Example 1

[0122] Synthesis of polyamidoamine C

[0123] Diethylmaleate (90g) was mixed with polyamine TEPA (38g) at room temperature. The mixing rate was regulated such that temperature of reaction mixture did not exceed 60 °C. The mixture was then heated to 145 °C and held for 6 hours.

[0124] The prepared polyamidoamine C had an amine density of 855 mgKOH / g based on amine value titration according to ASTM D2074-07(2019).

[0125] Synthesis of Polycaprolactone P1

[0126] Lauric acid (200.3g) and s-caprolactone (342.4g) were mixed and heat to 100 °C under N2. Zirconium butoxide (0.5 wt.%) was added and the mixture heated to 160 °C for 4 hours. On cooling, the product was obtained in the form of yellow solid. The reaction had a conversion of more than 95 % and the produced polycaprolactone P1 had a number average molecular weight of 1320 g / mole. The number average molecular weight Mn was determined using size exclusion chromatography according to ASTM D 5296.

[0127] Synthesis of Polycaprolactone P2

[0128] Lauric acid (200.3g) and s-caprolactone (1365.3g) were mixed and heat to 100 °C under N2. Zirconium butoxide (0.5 wt.%) was added and the mixture heated to 160 °C for 4 hours. On cooling, the product was obtained in the form of yellow solid. The reaction had a conversion of more than 95 % and the produced polycaprolactone P2 had a number average molecular weight of 3090 g / mole.

[0129] Synthesis of polyamidoamine-based additive

[0130] Polycaprolactone P1 (25g) and polycaprolactone P2 (75g) together with lauric acid (14g) were mixed with the polyamidoamine C (32g) prepared above and heated to 120 °C, and then held at such temperature for 6 hours. Thereby polycaprolactone P1 , polycaprolactone P2 and the carboxylic acid were linked to polyamidoamine C through covalent or non-covalent bond formation. The initial acid value of the mixture was 64 mgKOH / g. The final product had an acid value of 3 mgKOH / g, indicating substantial formation of new amide bonds between P1 , P2 and Q with polyamidoamine C. The acid value was determined according to ASTM D1639-90.

[0131] Slurry preparation

[0132] A NMC-based slurry, with a solid content of 70 wt.% (the solid comprises 96.75wt.% NMC, 1 .5 wt.% carbon black, 1 .5 wt.% PVDF and 0.25 wt.% additive) and a solvent content of 30 wt.% was prepared in a glovebox under argon atmosphere according to the following steps: a) a 8 wt.% PVDF Kynar® HSV 1810 in NMP solution (hereinafter “binder solution”) was prepared in an extra bottle. The binder solution was prepared by dissolving PVDF in NMP under mixing at 2000 rpm for 30 min in a dual asymmetric centrifuge mixer. b) 0.36 g of carbon black was weighed in a bottle, which is used for preparing the cathode slurry. Subsequently, the required amount of binder solution, 4.5 g, was weighed from the previously prepared binder solution in step a) and dispersed for 2 min at 2000 rpm. c) 0.06 g additive was added in the mixture obtained in step b) and was dispersed for 2 min at 2000 rpm. d) 23.22 g NMC 622 was added into the mixture obtained in step c) and dispersed for 1 min at 2000 rpm. e) Step-by-step with ca. 1 g per step the needed amount of 6.15 g NMP was added to the slurry until a solid content of 70 wt.% was reached. After each addition step of NMP, the slurry was dispersed for 1 min at 2000 rpm and cooled if the slurry had become warm.

[0133] The composition of the slurry followed the general recipe below. The solid content, which is calculated by the weight of NMC, Carbon Black, PVDF and additive divided to the total weight of the slurry including NMP, was 70 wt.%.

[0134] After the slurry was prepared for one hour, the slurry viscosity was measured. The maximum viscosity of the slurry reached 3.41 Pa s at 1 / s shear rate.

[0135] The C-rate average discharge specific capacity was measured for the cathode fabricated with the slurry containing additive of Example 1 according to the method as described above.

[0136] To evaluate the electrochemical stability and the effect of the additive on the cell performance, the results were compared to the C-rate average discharge specific capacity of the cathode obtained using the slurry described in Comparative Example 4. The results showed that the presence of the additive did not influence negatively the performance of the half cell. Each results was the average of three measurements on three different half cells.

[0137] To evaluate the capacity of the additives on dispersing carbon and carbon coated particles, a solution of 0.25 wt.% each additive in NMP was prepared by dispersing the additive in NMP for 2 minutes at 2000 rpm in a dual asymmetric centrifuge mixer, carbon black was stepwise added to the aforementioned solution until a carbon black content of 5 wt.% was reached and mixed for 2 minutes at 2000 rpm in the dual asymmetric centrifuge mixer to obtain an homogeneous dispersion.

[0138] The table below shows the recipe used for each example

[0139] The results in the table below show the viscosity of the obtained dispersions. The inventive additive improved dispersion of carbon black, measured through viscosity, compared to the same dispersion without additive.

[0140] Example 2

[0141] Slurry preparation

[0142] A LFP-based slurry, with a solid content of 60 wt.% (the solid comprised 96.85wt.% LFP, 0.7 wt.% carbon black, 2.2 wt.% PVDF and 0.25 wt.% polyamidoamine-based additive of Example 1 ) and a solvent content of 40 wt.% was prepared in a glovebox under argon atmosphere according to the following steps: a) a 8 wt.% PVDF Kynar® HSV 900 in NMP solution was prepared in an extra bottle. The binder solution was prepared by dissolving PVDF in NMP under mixing at 2000 rpm for 30 min in a dual asymmetric centrifuge mixer. b) 0.17 g of carbon black was weighed in a bottle, which was used for preparing the cathode slurry. Subsequently, the required amount of binder solution, 6.6 g, was weighed from the previously prepared binder solution in step a) and dispersed for 2 min at 2000 rpm. c) 0.06 g polyamidoamine-based additive prepared in Example 1 was added in the mixture obtained in step b) and was dispersed for 2 min at 2000 rpm. d) 23.24 g LFP was added into the mixture obtained in step c) and dispersed for 1 min at 2000 rpm. e) Step-by-step with ca. 1 g per step the needed amount of 9.9 g NMP was added to the slurry until a solid content of 60 wt.% was reached. After each addition step of NMP, the slurry was dispersed for 1 min at 2000 rpm and cooled if the slurry had become warm.

[0143] The slurry composition followed the general recipe below. The solid content which was calculated by the weight of LFP, carbon black, PVDF and additive divided to the total weight of the slurry including NMP, was 60 wt.%.

[0144] After the slurry was prepared for one hour, the slurry viscosity was measured. The maximum viscosity of the slurry reached 3.32 Pa s at shear rate of 1 / s.

[0145] Comparative Example 1

[0146] Polyamidoamine core functionalized with same polyesters but without capping Q as the structure of Example 1

[0147] Synthesis of comparative additive

[0148] Polycaprolactone 1 (P1 , 44.9g) and polycaprolactone 2 (P2, 118.3g) together were mixed with polyamidoamine C (33g) and heated to 120 °C, and then held at such temperature for 6 hours and thereby polycaprolactone P1 and P2 were linked to polyamidoamine C through covalent or non-covalent bond formation. The initial acid value of the mixture was 42 mgKOH / g. The final product had an acid value of 3 mgKOH / g, indicating substantial formation of new amide bonds between P1 and P2 with polyamidoamine C. The acid value was determined according to ASTM D1639- 90.

[0149] Slurry preparation

[0150] A NMC-based slurry was prepared according to the same method as that of Example 1 except that the additive of Comparative Example 1 was used. The composition of the slurry followed the general recipe below. The solid content was 70 wt.%.

[0151] After the slurry was prepared for one hour, the slurry viscosity was measured. The maximum viscosity of the slurry reached 65.01 Pa s at 1 / s shear rate.

[0152] Comparative Example 2

[0153] Polyamidoamine core functionalized with a single polyester and without capping C compared to the structure of Example 1

[0154] Synthesis of Polycaprolactone P3

[0155] Lauric acid (200.3g) and s-caprolactone (853.7g) were mixed and heat to 100 °C under N2. Zirconium butoxide (0.5 wt.%) was added and the mixture heated to 160 °C for 4 hours. On cooling, the product was obtained in the form of yellow solid. The reaction had a conversion of more than 95 % and the produced polycaprolactone P3 had a number average molecular weight of 2240 g / mole.

[0156] Synthesis of comparative additive

[0157] Polycaprolactone P3 (174.3g) was mixed with polyamidoamine C (48.6g) and heated to 120 °C, and then held at such temperature for 6 hours and thereby polycaprolactone P3 were linked to polyamidoamine A through covalent or non- covalent bond formation. The initial acid value of the mixture was 42 mg KOH / g. The final product had an acid value of 3 mgKOH / g, indicating substantial formation of new amide bonds between P3 with polyamidoamine C. The acid value was determined according to ASTM D1639-90.

[0158] Slurry preparation A NMC-based slurry was prepared according to the same method as that of Example 1 except that the additive of Comparative Example 2 was used. The composition of the slurry followed the general recipe below. The solid content was 70 wt.%.

[0159] After the slurry was prepared for one hour, the slurry viscosity was measured. The maximum viscosity of the slurry reached 44.14 Pa s at 1 / s shear rate.

[0160] Comparative Example 3

[0161] Polyamidoamine core functionalized with a single polyester and with the same capping C compared to the structure of Example 1

[0162] Synthesis of comparative additive

[0163] Polycaprolactone P3 (97.8g) together with lauric acid (13.5g) were mixed with the polyamidoamine C (31 g) prepared above and heated to 120 °C, and then held at such temperature for 6 hours. Thereby polycaprolactone P3 and the carboxylic acid were linked to polyamidoamine C through covalent or non-covalent bond formation. The initial acid value of the mixture was 64 mgKOH / g. The final product had an acid value of 2 mgKOH / g, indicating substantial formation of new amide bonds between P3 and Q with polyamidoamine C. The acid value was determined according to ASTM D 1639-90.

[0164] Slurry preparation

[0165] A NMC-based slurry was prepared according to the same method as that of Example 1 except that the additive of Comparative Example 3 was used. The composition of the slurry followed the general recipe below. The solid content was 70 wt.%. 1

[0166] After the slurry was prepared for one hour, the slurry viscosity was measured. The maximum viscosity of the slurry reached 51.12 Pa s at 1 / s shear rate.

[0167] Comparative Example 4

[0168] A NMC-based slurry was prepared according to the same method as that of Example 1 except that no additive was used and that the slurry composition followed the general recipe below. The solid content was 70 wt.%.

[0169] One hour after production, the slurry viscosity was measured. The maximum viscosity of the slurry reached 29.69 Pa s at 1 / s shear rate.

[0170] Comparative Example 5

[0171] A NMC-based slurry was prepared according to the same method as that of Example 1 except that PVP was used as the additive. The slurry composition followed the general recipe below. The solid content was 70 wt.%.

[0172] One hour after production, the slurry viscosity was measured. The maximum viscosity of the slurry reached 6.02 Pa s at 1 / s shear rate.

[0173] Comparative Example 6

[0174] Synthesis Polycaprolactone P1 (25g) and polycaprolactone P2 (75g) together with lauric acid (11 g) were mixed with polyethyleneimine, Mn 2000 (21g) (Lupasol® PR 8515 from BASF) and heated to 120 °C, and then held at such temperature for 6 hours. Thereby polycaprolactone P1 , polycaprolactone P2 and the carboxylic acid were linked to polyethyleneimine through covalent or non-covalent bond formation. The initial acid value of the mixture was 64 mgKOH / g. The final product had an acid value of 2 mgKOH / g, indicating substantial formation of new amide bonds between P1 , P2 and Q with polyethyleneimine. The acid value was determined according to ASTM D1639-90.

[0175] Slurry preparation

[0176] A NMC-based slurry was prepared according to the same method as that of Example 1 except that the additive of Comparative Example 6 was used. The composition of the slurry followed the general recipe below. The solid content was 70 wt.%.

[0177] After the slurry was prepared for one hour, the slurry viscosity was measured. The maximum viscosity of the slurry reached 4.88 Pa s at 1 / s shear rate.

[0178] Comparative Example 7

[0179] Slurry preparation

[0180] A LFP-based slurry was prepared according to the same method as that of Example 2 except that no additive was used and that the slurry composition followed the general recipe below. The solid content of the slurry composition was 60 wt.%.

[0181] After the slurry was prepared for one hour, the slurry viscosity was measured. The maximum viscosity of the slurry reached 4.99 Pa s at 1 / s shear rate.

[0182] The viscosity reduction performance of the dispersing agents was summarized in Table 1 below:

[0183] Table 1

[0184] As shown in Table 1 , the dispersing agents of Comparative Example 1 to Comparative Example 3 did not have the viscosity reduction effect. Surprisingly, the inventive dispersing agent which had a similar structure to those of Comparative Example 1 to Comparative Example 3 could disperse the NMC and carbon black particles in NMP with greatly reduced viscosity. In particular, compared with PVP (Comparative Example 5), which is commonly used as dispersing agent for lithium- ion battery cathodes, the viscosity reduction efficacy of the inventive dispersing agent was even much better. The viscosity reduction efficacy of the inventive dispersing agent was also much better than the dispersant based on PEI (Comparative Example 6).

[0185] As used herein, terms such as “comprise(s)” and the like as used herein are open terms meaning “including at least” unless otherwise specifically noted.

[0186] All references, tests, standards, documents, publications, etc. mentioned herein are incorporated herein by reference. Where a numerical limit or range is stated, the endpoints are included. Also, all values and subranges within a numerical limit or range are specifically included as if explicitly written out. The above description is presented to enable a person skilled in the art to make and use the invention and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, this invention is not intended to be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features disclosed herein. In this regard, certain embodiments within the invention may not show every benefit of the invention, considered broadly.

Claims

Claims1. A dispersant obtained by reacting a polyamidoamine C with at least two polyesters P and at least one carboxylic acid or its anhydride or its ester Q; wherein said polyamidoamine C is obtainable from repetitive self-reaction of at least one type of substance B and I or from cross-reaction of at least one B with at least one substance A, wherein the at least one B is an adduct of the at least one substance A and at least one linker D, and B contains 1 -15 amine-reactive groups and 4-15 in total number of primary, secondary, tertiary and quaternary amines, the at least one substance A is a branched and I or linear aliphatic and I or cycloaliphatic or aromatic polyamine containing 4-15 total number of primary, secondary, tertiary and quaternary amines, and the at least one linker D is an acrylate, a maleate I fumarate mono-ester or a maleate I fumarate di-ester containing 1 -15 amine-reactive groups, or a mixture thereof; wherein the amine-reactive groups in B and D are reacted with reactive amines in B and I or A, and if B has only one amine reactive group, then additional D and I or mixture of B and A is reacted to a previously formed C, wherein such additional reaction of D and I or mixture of B and A to a formed C is repeated for 1 to 10 times; and wherein said at least two polyesters P each having one or more amine reactive groups.

2. The dispersant of claim 1 , wherein the amount of polyamidoamine C is 5-50 wt.%, preferably 5-30 wt.%; the amount of polyester P is 30-90 wt.%, preferably 40-90 wt.% and the amount of carboxylic acid or its anhydride or its ester Q is 5-20 wt.%, preferably 5-15 wt.%, based on the total amount of polyamidoamine C, polyester P and carboxylic acid or its anhydride or its ester Q.

3. The dispersant of claim 1 , wherein the polyamidoamine C has an amine density of at least 600 mgKOH / g and / or less than 1000 mg KOH / g, preferably from 700 mg KOH / g to 1 ,000 mg KOH / g, more preferably from 700 mg KOH / g to 900 mg KOH / g.

4. The dispersant of claim 1 , wherein the at least two polyesters P comprise a first polyester and a second polyester, the number averaged molecular weight difference between the first polyester and the second polyester is at least 300, preferably at least 500 g / mole; preferably the number averaged molecular weight difference between the first polyester and the second polyester is below 5000, preferably below 3500 g / mole.

5. The dispersant of claim 1 , wherein the polyesters P have different chain lengths and are obtainable from ring opening polymerization of lactones and / or lactide, and the polyester P has a number averaged molecular weight of 500-20000 g / mole.

6. The dispersant of claim 1 , wherein the carboxylic acid or its anhydride or its ester Q is selected from aliphatic acids, aromatic acids and esters or anhydrides thereof.

7. The dispersant according to any one of claims 1 to 6, characterized in that the polyester P is a polylactone or polycaprolactone.

8. The dispersant according to any one of claims 1 to 7, characterized in that the substance B has 2 to 15 amine-reactive groups and additional D and / or mixture of B and A is reacted to a previously formed C, such additional reaction of D and / or mixture of B and A to a formed C is repeated for 1 to 10 times.

9. The dispersant according to any one of claims 1 to 8, characterized in that the substance A is selected from the group consisting of triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

10. A dispersant based on polyamidoamines, wherein the dispersant has the formula (I):Formula (I) in whichX-*-*-*-X is a polyamidoamine, each comprising primary and / or secondary amino groups,are POAC side chains which are side chains based on poly(oxy-Ci-6- alkylenecarbonyl) compounds, with T = a saturated or unsaturated alkyl group,V = an -Ci-6-alkylene group, each of m, n, r and t is an average number, m and n = each 3 to 40, where m and n are different from one another, preferably the difference between m and n is from 3 to 35, especially from 5 to 20, r and t = each 1 to 100, andZ are side chains based on carboxylic acids or anhydrides or esters thereof Q with s = 1 to 100, preferably the carboxylic acid is selected from the group consisting of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid.11 . A process for producing a dispersant comprising the steps of a) repetitive self-reaction of at least one type of substance B and / or crossreaction of at least one B with at least one A to produce polyamidoamines C having an amine density of at least 600 mg KOH / g, withB being an adduct of at least one substance A and at least one linker D and B containing 1 -15 amine-reactive groups and 4-15 in total number of primary, secondary, tertiary and quaternary amines,A being a branched and / or linear aliphatic and / or cycloaliphatic or aromatic polyamine containing 4-15 total number of primary, secondary, tertiary and quaternary amines, linker D being an acrylate, maleate / fumarate mono-ester or maleate / fumarate diester containing 1 -15 amine-reactive groups, or mixture thereof, the amine-reactive groups in B and D are reacted with reactive amines in B and / or A and if B has only one amine reactive group then additional D and / or mixture of B and A is reacted to a previously formed C, such additional reaction of D and / or mixture of B and A to a formed C is repeated for 1 to 10 times; and b) reacting the polyamidoamines C with at least two polyesters P each having one or more amine reactive groups together with substance Q, wherein substance Q is a non-polymeric molecule selected from the group consisting of carboxylic acid, carboxylic ester, or carboxylic anhydride.

12. The process for producing a dispersant according to claim 10, characterized in that the polyamidoamines C have an amine density of 600 mg KOH / g to 1 ,000 mg KOH / g.

13. The process for producing a dispersant according to claim 11 , characterized in that the polyester P is a polylactone or polycaprolactone.

14. The process for producing a dispersant according to any one of claims 11 to 13, characterized in that the substance B has 2 to 15 amine-reactive groups andadditional D and / or mixture of B and A is reacted to a previously formed C, such additional reaction of D and / or mixture of B and A to a formed C is repeated for 1 to 10 times.

15. The process for producing a dispersant according to any one of claims 11 to 14, characterized in that A is selected from the group consisting of triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

16. A method for preparing a dispersant, preferably the dispersant of any one of claims 1 -10, preferably comprising the reaction of polyamidoamine C with at least two or more polyesters P based on poly(oxy-Ci-6-alkylenecarbonyl) compounds according towith T = a saturated or unsaturated alkyl group,V = an -Ci-6-alkylene group, each of m, n, r and t is an average number, m and n = each 3 to 40, where m and n are different from one another, preferably the difference between m and n is from 3 to 35, especially from 5 to 20, r and t = each 1 to 100, and carboxylic acids or anhydrides or esters thereof Q, wherein an amidation of carboxylic acids or anhydrides or esters thereof Q with the polyamidoamine C takes place, preferably the carboxylic acid is selected from the group consisting of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid.

17. A dispersion comprising a continuous phase, a dispersed particulate and the dispersant according to any one of claims 1 -10 or the dispersant prepared according to the method of any one of claims 11 -16.

18. The dispersion of claim 17, wherein the dispersed particulate is selected from cathode active materials and / or the dispersion is an electrode slurry.

19. An electrochemical device comprising the dispersant according to any one of claims 1 -10 or the dispersion according to claim 17 or 18.

20. Use of the dispersant according to any one of claims 1-10 in preparation of an electrode in a battery, especially to disperse a cathode active material in an electrode slurry.

21. Use of the dispersion according to claim 17 or 18 in preparation of an electrochemical device including batteries.

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