Hyperbranched dispersant and preparation method thereof

Abstract

The invention discloses a hyperbranched dispersant and a preparation method thereof. The invention provides a hyperbranched polymer. The hyperbranched polymer is prepared from a trifunctional compound A and a trifunctional compound B through a reaction. The hyperbranched dispersant provided by the invention has good dispersion and anti-cracking effects on the lithium battery positive electrode slurry.

Description

Technical Field

[0001] The invention relates to a hyperbranched dispersant and a preparation method thereof. Background Art

[0002] Hyperbranched dispersants have special structural characteristics with multi-branched central atoms and multiple anchor points on the side chains. On the one hand, they can greatly improve the dispersion effect of positive electrode active materials and conductive agents in them to improve the uniformity of positive electrode sheets. On the other hand, they can increase the solid content of positive electrode slurry to improve the coating performance of positive electrode slurry and increase the yield and production capacity of positive electrode sheets. Summary of the invention

[0003] The invention provides a hyperbranched dispersant and a preparation method thereof. The hyperbranched dispersant of the invention is prepared by reacting a trifunctional compound A and a trifunctional compound B, and the dispersant has good dispersing and anti-cracking effects on lithium battery positive electrode slurry.

[0004] The present invention provides a hyperbranched polymer, wherein the hyperbranched polymer is prepared by reacting a compound A and a compound B, wherein the reaction molar ratio of the compound A to the compound B is (1-1.2): (0.5-1);

[0005] Wherein, compound A is one or more of citric acid, 1,2,3-cyclohexanetricarboxylic acid, isocitric acid, 3-phospho-1,3,5-pentanetricarboxylic acid, nitrilotriacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, benzotricarboxylic acid, 2-methylpropanetricarboxylic acid, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid and 1,2,4-butanetricarboxylic acid;

[0006] Compound B is one or more of triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, tris(diaminoethyl)amine, the compound represented by the general structural formula (1), the compound represented by the general structural formula (2), the compound represented by the general structural formula (3) and the compound represented by the general structural formula (4);

[0007] The general structural formula (1) is as follows:

[0008]

[0009] wherein n is an integer of 0-14, x is an integer of 1-34, y is an integer of 1-34, z is an integer of 1-34, 3≤x+y+z≤90, and R is -C2H5 or H;

[0010] The general structural formula (2) is as follows:

[0011]

[0012] Wherein, x1 and y1 are each independently an integer between 0 and 56, and x1 and y1 are not 0 at the same time;

[0013] The general structural formula (3) is as follows:

[0014]

[0015] Wherein: x2 and y2 are each independently an integer of 0-56; and x2 and y2 are not 0 at the same time, and R1 is methyl or ethyl;

[0016] The structure of structural formula (4) is as follows:

[0017]

[0018] In one embodiment, compound A is citric acid, isocitric acid, 3-phospho-1,3,5-pentanetricarboxylic acid, nitrilotriacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, 2-methylpropanetricarboxylic acid, 1,2,4-benzenetricarboxylic acid or 1,2,4-butanetricarboxylic acid.

[0019] In one embodiment, compound B is triisopropanolamine, diethanol monoisopropanolamine, tris(diaminoethyl)amine, a compound represented by the general structural formula (1), a compound represented by the general structural formula (2), or a compound represented by the general structural formula (3).

[0020] In one embodiment, the compound represented by the general structural formula (1) is a polyetheramine having a molecular weight of 400-6000;

[0021] Preferably, the compound represented by the general structural formula (1) is a polyetheramine with a CAS number of 39423-51-3 and a molecular weight of 400-600 or a polyetheramine with a CAS number of 9046-10-0 and a molecular weight of 4000-6000;

[0022] More preferably, the compound represented by the general structural formula (1) is Huntsman polyetheramine T403 or Huntsman polyetheramine T5000.

[0023] In a certain embodiment, the compound represented by the general structural formula (2) is polyoxyethyl glyceryl ether with a molecular weight of 500-2000 or polyoxyethyl polyoxypropyl glyceryl ether with a molecular weight of 1000-6000;

[0024] Preferably, the compound represented by the general structural formula (2) is a polyetheramine with a CAS number of 31694-55-0 and a molecular weight of 500-1500 or a polyetheramine with a CAS number of 9082-00-2 and a molecular weight of 3000-5000;

[0025] More preferably, the compound represented by the general structural formula (2) is a polyetheramine with a CAS number of 31694-55-0 and a molecular weight of 900 or 1200 or a polyetheramine with a CAS number of 9082-00-2 and a molecular weight of 4000.

[0026] In one embodiment, the compound represented by the general structural formula (3) is trimethylolpropane polyoxyethylene ether with a molecular weight of 300-2000 or trimethylolpropane poly(oxypropylene) triether with a molecular weight of 200-1000;

[0027] Preferably, the compound represented by the general structural formula (3) is trimethylolpropane polyoxyethylene ether with a CAS number of 50586-59-9 and a molecular weight of 500-1500 or trimethylolpropane poly(oxypropylene) triether with a CAS number of 25723-16-4 and a molecular weight of 200-8000;

[0028] More preferably, the compound represented by the general structural formula (3) is trimethylolpropane polyoxyethylene ether with a CAS number of 50586-59-9 and a molecular weight of 1014 or trimethylolpropane poly(oxypropylene) triether with a CAS number of 25723-16-4 and a molecular weight of 308.

[0029] In one embodiment, in the general structural formula (1), n ​​is 0 or 1, x is an integer of 1-34, y is an integer of 1-34, z is an integer of 1-34, 3≤x+y+z≤90, and R is -C2H5 or H;

[0030] Preferably, in the general structural formula (1), n ​​is 1, x, y and z are each independently an integer of 1-5, 3≤x+y+z≤10, and R is -C2H5; or, n is 0, x, y and z are each independently an integer of 20-34, 60≤x+y+z≤90, and R is H;

[0031] More preferably, in the general structural formula (1), n ​​is 1, x, y and z are each independently an integer of 1-2, 5≤x+y+z≤6, and R is -C2H5; or, n is 0, x, y and z are each independently an integer of 26-30, 80≤x+y+z≤90, and R is H.

[0032] In one embodiment, in the general structural formula (2), x1 is independently 0-30, y1 is independently 0-15, and 5≤x1+y1≤30;

[0033] Preferably, in the general structural formula (2), x1 is independently 1-15, y1 is independently 0-10, and 5≤x1+y1≤15;

[0034] More preferably, in the general structural formula (2), x1 is independently 6-12, and y1 is 0; or, x1 is independently 1-2, and y1 is 8-9.

[0035] In one embodiment, in the general structural formula (3), x2 is independently an integer of 2-10, y2 is 0, and R1 is methyl or ethyl.

[0036] In one embodiment, in the general structural formula (3), x2 is independently an integer of 2-4, y2 is 0, and R1 is a methyl group; or, x2 is independently an integer of 6-8, y2 is 0, and R1 is an ethyl group.

[0037] In one embodiment, compound A is citric acid;

[0038] Compound B is a polyetheramine with a CAS number of 39423-51-3 and a molecular weight of 440; Compound B is, for example, Huntsman T403.

[0039] In one embodiment, compound A is 3-phosphoryl-1,3,5-pentanetricarboxylic acid;

[0040] Compound B is diethanol monoisopropanolamine.

[0041] In one embodiment, compound A is 2-phosphonobutane-1,2,4-tricarboxylic acid;

[0042] Compound B is tris(diaminoethyl)amine.

[0043] In one embodiment, compound A is 2-methylpropanetricarboxylic acid;

[0044] Compound B is polyoxyethyl glycerol ether with CAS No. 31694-55-0 and molecular weight of 1200; Compound B is polyetheramine with merchant McLean product No. G909231.

[0045] In one embodiment, compound A is 1,2,4-benzenetricarboxylic acid;

[0046] Compound B is trimethylolpropane polyoxyethylene ether with a CAS number of 50586-59-9 and a molecular weight of 1014.

[0047] In one embodiment, compound A is isocitrate;

[0048] Compound B is trimethylolpropane poly(oxypropylene) triether with a CAS number of 25723-16-4 and a molecular weight of 308.

[0049] In one embodiment, compound A is 1,2,4-butanetricarboxylic acid;

[0050] Compound B is polyoxyethyl polyoxypropyl glyceryl ether with a CAS number of 9082-00-2 and a molecular weight of 4000.

[0051] In one embodiment, compound A is 2-methylpropanetricarboxylic acid;

[0052] Compound B is a polyetheramine with a CAS number of 9046-10-0 and a molecular weight of 5000; Compound B is, for example, Huntsman T5000.

[0053] In one embodiment, compound A is 2-phosphonobutane-1,2,4-tricarboxylic acid;

[0054] Compound B is glycerol polyoxyethylene ether with a CAS number of 31694-55-0 and a molecular weight of 900.

[0055] In one embodiment, compound A is nitrilotriacetic acid;

[0056] Compound B is triisopropanolamine.

[0057] In one embodiment, the reaction is carried out in the presence of N-methylpyrrolidone;

[0058] Preferably, the total mass ratio of N-methylpyrrolidone to compound A and compound B is 1:0.5-3, preferably 1:1-2.5, such as 1:1 or 1:2.

[0059] In one embodiment, the reaction is carried out at 80-120° C. under reduced pressure for 1-4 h, then at 125-160° C. under normal pressure for 2-6 h, and finally at 125-160° C. under reduced pressure for 2-6 h.

[0060] In a certain embodiment, the reaction may further include a catalyst, and the catalyst is one or more of methanesulfonic acid, N,N,N,N,N-pentamethyldiethylenetriamine, triethylenediamine, dimethylaminopyridine, 4-pyrrolylpyridine, N,N-dicyclohexylcarbodiimide, diisopropylcarbodiimide, p-toluenesulfonic acid and 1-hydroxybenzotriazole; the catalyst is preferably 4-pyrrolylpyridine, triethylenediamine, methanesulfonic acid or 1-hydroxybenzotriazole;

[0061] Preferably, the total mass ratio of the catalyst and compound A to compound B is 100:(0.1-5), preferably 100:(1-3).

[0062] In one embodiment, the reaction comprises the following steps:

[0063] Step 1: In N-methylpyrrolidone, compound A and compound B are reacted at a temperature of 80 to 120° C. and a vacuum degree of -0.07 to -0.1 MPa for 1 to 6 hours;

[0064] Step 2: react at a temperature of 125 to 160° C. and a pressure of normal pressure for 1 to 8 hours;

[0065] Step 3: reacting for 1-8 hours at a temperature of 125-160° C. and a vacuum degree of -0.07-0.1 MPa to obtain the hyperbranched polymer.

[0066] The present invention also provides a method for preparing the above-mentioned hyperbranched polymer, comprising the following steps:

[0067] Step 1: Compound A and Compound B react in N-methylpyrrolidone at a temperature of 80-120° C. under reduced pressure;

[0068] Step 2: reacting at a temperature of 125-160°C and a pressure of normal pressure;

[0069] Step 3: reacting at a temperature of 125-160° C. and under reduced pressure to obtain the hyperbranched polymer.

[0070] In one embodiment, the reaction molar ratio of compound A to compound B is 1:0.5-1.5.

[0071] In a certain embodiment, the total mass ratio of N-methylpyrrolidone and compound A to compound B is 1:0.5-3, preferably 1:1-2.5, such as 1:1 or 1:2.

[0072] In a certain embodiment, the reaction may further include a catalyst, and the catalyst is one or more of methanesulfonic acid, N,N,N,N,N-pentamethyldiethylenetriamine, triethylenediamine, dimethylaminopyridine, 4-pyrrolylpyridine, N,N-dicyclohexylcarbodiimide, diisopropylcarbodiimide, p-toluenesulfonic acid and 1-hydroxybenzotriazole; the catalyst is preferably 4-pyrrolylpyridine, triethylenediamine, methanesulfonic acid or 1-hydroxybenzotriazole;

[0073] Preferably, the total mass ratio of the catalyst and compound A to compound B is 100:(0.1-5), preferably 100:(1-3).

[0074] In one embodiment, in step 1, the temperature is 80, 58, 90, 95, 100, 105, 110, 115 or 120°C.

[0075] In one embodiment, in step 1, the reduced pressure is -0.07 to -0.1 MPa, preferably -0.08 to -0.095 MPa, for example, 0.08 to -0.083 MPa, -0.08 to -0.085 MPa, -0.082 to -0.085 MPa, -0.085 to -0.087 MPa, -0.088 to -0.090 MPa or -0.092 to -0.095 MPa.

[0076] In one embodiment, in step 1, the reaction time is 1-6 h, preferably 1-4 h, such as 1, 2, 3 or 4 h.

[0077] In one embodiment, in step 2, the temperature is 150-160°C, such as 150, 155 or 160°C.

[0078] In one embodiment, in step 2, the reaction time is 1-8 h, preferably 2-6 h, for example 2, 3, 4, 5 or 6 h.

[0079] In one embodiment, in step three, the temperature is 140-160°C, such as 140, 150 or 155°C.

[0080] In one embodiment, in step three, the reduced pressure is -0.07 to -0.1 MPa, preferably -0.085 to -0.01 MPa, for example -0.09 to -0.092 MPa or -0.093 to -0.095 MPa.

[0081] In one embodiment, in step three, the reaction time is 1-8 h, preferably 2-6 h, for example 2, 3, 4, 5 or 6 h.

[0082] In one embodiment, after the reaction in step 3 is completed, a dilution step with N-methylpyrrolidone is further included; preferably, the dilution step is to add N-methylpyrrolidone to dilute to a solid content of 45-55%, preferably 50%.

[0083] In one embodiment, the reaction comprises the following steps:

[0084] Step 1: In N-methylpyrrolidone, compound A and compound B are reacted at a temperature of 90 to 120°C and a pressure of -0.08 to -0.095 MPa for 1 to 4 hours;

[0085] Step 2: react at a temperature of 140-160°C and a pressure of normal pressure for 2-6 hours;

[0086] Step 3: reacting for 2-6 hours at a temperature of 140-160° C. and a pressure of -0.085-0.01 MPa, and diluting with N-methylpyrrolidone to a solid content of 45-55% to obtain the hyperbranched polymer.

[0087] The present invention also provides a hyperbranched polymer, which is prepared by the above-mentioned method for preparing the hyperbranched polymer.

[0088] The present invention also provides a dispersant composition, which comprises the hyperbranched polymer and N-methylpyrrolidone.

[0089] The present invention also provides a use of the hyperbranched polymer as a dispersant in a positive electrode slurry.

[0090] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0091] The reagents and raw materials used in the present invention are commercially available.

[0092] The positive improvement effect of the present invention is that the hyperbranched dispersant of the present invention has good dispersing and anti-cracking effects on lithium battery positive electrode slurry. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 is the infrared spectrum of the citric acid raw material in Example 1;

[0094] Figure 2 is the infrared spectrum of the polyetheramine raw material in Example 1;

[0095] Figure 3 It is the infrared spectrum of the product in Example 1. DETAILED DESCRIPTION

[0096] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0097] Example 1

[0098] (1) 192.1 g of citric acid and 440 g of polyetheramine T403 (CAS: 39423-51-3, manufacturer: Huntsman; molecular weight: 440) were added to a reaction kettle, and 316.05 g of solvent N-methylpyrrolidone was added, the temperature was raised to 100° C., and vacuum dehydration was performed at a vacuum condition of -0.085 to -0.087 MPa for 2 h, and then the pressure was restored to normal;

[0099] (2) raising the reaction temperature to 150°C and continuing to stir the reaction at this temperature for 4 hours;

[0100] (3) At 150°C, maintain the vacuum condition of -0.090 to -0.092 MPa and continue the dehydration reaction for 4 h. After the reaction is completed, cool to 80°C and add 316.05 g of solvent N-methylpyrrolidone to dilute and adjust the solid content to 50% to obtain the target product M1;

[0101] The infrared spectra of the raw materials citric acid and polyetheramine (T403) used are shown in Figure 1 and Figure 2 The infrared spectrum of the obtained product is shown in Figure 3 .like Figure 1-3 As shown in the figure, the peak with a wave number of 1703.34 cm-1 in the reaction product corresponds to the peak of 1708.25 cm-1 of the raw material citric acid, which corresponds to the stretching vibration peak of C=O in the carboxyl group. The red shift of the wave number is caused by the fact that the N on the -NH- in the amide bond formed in the product has a lone pair of electrons that form a conjugation with the C=O bond, and the functional group in the product changes from a carboxylic acid group to an amide group. On the other hand, the wave number of the raw material citric acid at 3000-2500 cm-1 is the stretching vibration of the -OH bond in the carboxyl group, and 1200-1300 cm-1 corresponds to the stretching vibration of the CO bond in the carboxyl group. In contrast, the peak signal value disappears in this wave number range in the product, which indirectly indicates that the content of carboxyl groups in the product has decreased significantly. The wave number of 2923.70 cm-1 in the reaction product corresponds to the peak of 2865.44 cm-1 in the reactant T403, which is the stretching vibration of -CH2- on the polyether chain segment; this indicates that the polyether structure in the product is inherited from the raw material T403.

[0102] Example 2

[0103] (1) 284.2 g of 3-phosphoryl-1,3,5-pentanetricarboxylic acid and 114.2 g of diethanol monoisopropanolamine were added to a reaction kettle, and 199.2 g of solvent N-methylpyrrolidone was added, the temperature was raised to 95° C., and vacuum dehydration was performed under vacuum conditions of -0.088 to -0.090 MPa for 2 h, and then the pressure was restored to normal;

[0104] (2) raising the reaction temperature to 125°C and continuing to stir the reaction at this temperature for 4 hours;

[0105] (3) The temperature was raised to 155° C. and the dehydration reaction was continued for 4 h under vacuum conditions of -0.090 to -0.092 MPa. After the reaction was completed, the temperature was lowered to 80° C. and 398.4 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 40% to obtain the target product M2.

[0106] Example 3

[0107] (1) 148.6 g of 2-phosphonobutane-1,2,4-tricarboxylic acid (CAS: 37971-36-1, trade name: Merck, molecular weight: 270.1) and 73.1 g of tris(diaminoethyl)amine (CAS: 4097-89-6, molecular weight: 146.2) were added to a reaction kettle, and 110.9 g of solvent N-methylpyrrolidone was added, and the temperature was raised to 105° C., and vacuum dehydration was performed at a vacuum condition of -0.088 to -0.090 MPa for 3 h, and then the pressure was restored to normal;

[0108] (2) Raise the reaction temperature to 155°C and continue stirring the reaction at this temperature for 4 hours;

[0109] (3) The dehydration reaction was continued at 155° C. under vacuum conditions of -0.090 to -0.092 MPa for 4 h. After the reaction was completed, the temperature was lowered to 80° C., and 110.9 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 50% to obtain the target product M3.

[0110] Example 4

[0111] (1) 47.6 g of 2-methylpropane tricarboxylic acid and 210.0 g of polyoxyethyl glycerol ether (CAS: 31694-55-0, merchant: McLean, product number: G909231, molecular weight: 1200) were added to a reaction kettle, and 257.6 g of solvent N-methylpyrrolidone was added, and the temperature was raised to 120° C., and vacuum dehydration was performed at a vacuum condition of -0.092 to -0.095 MPa for 4 h, and then the pressure was restored to normal;

[0112] (2) Raising the reaction temperature to 150°C and continuing to stir the reaction at this temperature for 6 hours;

[0113] (3) The dehydration reaction was continued at 150° C. under vacuum conditions of -0.093 to -0.095 MPa for 6 h. After the reaction was completed, the temperature was lowered to 80° C., and 515.2 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 25% to obtain the target product M4.

[0114] Example 5

[0115] (1) 63.0 g of 1,2,4-benzenetricarboxylic acid and 212.9 g of trimethylolpropane polyoxyethylene ether (CAS: 50586-59-9, trade name: McLean, molecular weight: 1014) were added to a reaction kettle, and 138 g of solvent N-methylpyrrolidone was added, and the temperature was raised to 115° C., and vacuum dehydration was performed at a vacuum condition of -0.082 to -0.085 MPa for 2 h, and then the pressure was restored to normal;

[0116] (2) raising the reaction temperature to 150°C and continuing to stir the reaction at this temperature for 4 hours;

[0117] (3) The dehydration reaction was continued at 150° C. under vacuum conditions of -0.093 to -0.095 MPa for 4 h. After the reaction was completed, the temperature was lowered to 80° C., and 138 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 50% to obtain the target product M5.

[0118] Example 6

[0119] (1) 230.6 g of isocitric acid and 308 g of trimethylolpropane poly(oxypropylene) triether (CAS: 25723-16-4, supplier: Yuanmu Biotechnology, molecular weight: 308) were added to a reaction kettle, and 269.3 g of solvent N-methylpyrrolidone was added, the temperature was raised to 110° C., and vacuum dehydration was performed at a vacuum condition of -0.082 to -0.085 MPa for 3 h, and then the pressure was restored to normal;

[0120] (2) Raise the reaction temperature to 155°C and continue stirring the reaction at this temperature for 4 hours;

[0121] (3) The dehydration reaction was continued at 155° C. under vacuum conditions of -0.090 to -0.092 MPa for 4 h. After the reaction was completed, the temperature was lowered to 80° C., and 269.3 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 50% to obtain the target product M6.

[0122] Example 7

[0123] (1) 19.0 g of 1,2,4-butanetricarboxylic acid and 200.0 g of polyoxyethyl polyoxypropyl glyceryl ether (CAS: 9082-00-2, trader: McLean, molecular weight: 4000) were added to a reaction kettle, 109.5 g of solvent N-methylpyrrolidone was added, and then 4.38 g of 4-pyrrolylpyridine was added, the temperature was raised to 80° C., and vacuum dehydration was performed at a vacuum condition of -0.082 to -0.085 MPa for 2 h, and then the pressure was restored to normal;

[0124] (2) Raise the reaction temperature to 150°C and continue stirring the reaction at this temperature for 3 hours;

[0125] (3) The dehydration reaction was continued at 150° C. under vacuum conditions of -0.090 to -0.092 MPa for 3 h. After the reaction was completed, the temperature was lowered to 80° C., and 547.5 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 25% to obtain the target product M7.

[0126] Example 8

[0127] (1) 22.8 g of 2-methylpropanetricarboxylic acid and 250.0 g of polyetheramine T5000 (CAS: 9046-10-0, supplier: Huntsman, molecular weight: 5000) were added to a reaction kettle, 272.8 g of solvent N-methylpyrrolidone was added, and then 8.18 g of methanesulfonic acid was added, the temperature was raised to 85° C., and vacuum dehydration was performed at a vacuum condition of -0.080 to -0.085 MPa for 2 h, and then the pressure was restored to normal;

[0128] (2) raising the reaction temperature to 150°C and continuing to stir the reaction at this temperature for 4 hours;

[0129] (3) The dehydration reaction was continued at 150° C. under vacuum conditions of -0.090 to -0.092 MPa for 4 h. After the reaction was completed, the temperature was lowered to 80° C., and 537.4 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 25% to obtain the target product M8.

[0130] Example 9

[0131] (1) 64.8 g of 2-phosphonobutane-1,2,4-tricarboxylic acid and 180.8 g of glycerol polyoxyethylene ether (CAS: 31694-55-0, supplier: Shanghai Jizhi Biochemical Technology Co., Ltd., molecular weight: 900) were added to a reaction kettle, 122.4 g of solvent N-methylpyrrolidone was added, and then 4.9 g of triethylenediamine was added, the temperature was raised to 85° C., and vacuum dehydration was performed under vacuum conditions of -0.080 to -0.085 MPa for 2 h, and then the pressure was restored to normal;

[0132] (2) raising the reaction temperature to 150°C and continuing to stir the reaction at this temperature for 4 hours;

[0133] (3) The dehydration reaction was continued at 150° C. under vacuum conditions of -0.090 to -0.092 MPa for 4 h. After the reaction was completed, the temperature was lowered to 80° C., and 239.9 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 40% to obtain the target product M9.

[0134] Example 10

[0135] (1) 191.1 g of nitrilotriacetic acid and 172.2 g of triisopropanolamine were added to a reaction kettle, 181.6 g of solvent N-methylpyrrolidone was added, and then 3.6 g of 1-hydroxybenzotriazole was added, the temperature was raised to 80° C., and vacuum dehydration was performed under vacuum conditions of -0.080 to -0.083 MPa for 2 h, and then the pressure was restored to normal;

[0136] (2) raising the reaction temperature to 155°C and continuing to stir the reaction at this temperature for 3 hours;

[0137] (3) The dehydration reaction was continued at 155° C. under vacuum conditions of -0.090 to -0.092 MPa for 3 h. After the reaction was completed, the temperature was lowered to 80° C., and 178.1 g of solvent N-methylpyrrolidone was added to dilute and adjust the solid content to 50% to obtain the target product M10.

[0138] Application examples:

[0139] Cathode slurry preparation:

[0140] The positive electrode materials LFP powder (lithium iron phosphate powder) and Super P (conductive carbon black powder) were placed in a dry and clean beaker respectively, and then placed in a vacuum drying oven and vacuum dried at 100°C for 12 hours; PVDF powder was weighed in a plastic can, N-methylpyrrolidone (NMP) solvent was added, the can was covered, and the can was mixed in a planetary mixer to obtain a binder solution with a solid content of 6%; the components of the positive electrode slurry of the lithium battery were wet-mixed with NMP using a planetary degassing machine according to the proportions in Table 1 to obtain the positive electrode slurry of the application example, the blank group was the positive electrode slurry obtained without adding any additives, and the amount of active material was adjusted to 97.2%. The proportions of the components of the positive electrode slurry are shown in Table 1, and the amounts of all components of the positive electrode slurry are shown in Table 2.

[0141] Table 1 Data on the proportion of each component in the positive electrode slurry

[0142]

[0143] Table 2 Amount of each component of positive electrode slurry

[0144]

[0145] The PVDF was added in the form of 6 wt % PVDF NMP glue solution, that is, 55.44 g of glue solution was added, which contained 3.326 g of PVDF.

[0146] The hyperbranched dispersant is added in the form of a dispersant solution in the embodiment. For example, 0.739 g of a solution containing a dispersant at a mass concentration of 50% is added to slurry 1, which contains 0.3696 g of a hyperbranched dispersant.

[0147] The solid content of the slurry means: the mass percentage of solids in the slurry. The solids in the positive electrode slurry in Table 2 include the solid mass of carbon-coated lithium iron phosphate, conductive agent, PVDF and the solid mass of the dispersing agent in the dispersing agent solution.

[0148] Cathode slurry test:

[0149] (1) Viscosity test: The viscosity test is carried out using a digital display rotational viscometer. The sample is placed in a 25°C constant temperature box for 2 hours until the sample temperature reaches 25°C. A No. 64 rotor is used. The digital display data at 3 minutes of testing is the viscosity test data. After the sample is placed in a 25°C constant temperature box for 24 hours, a No. 64 rotor is used. The digital display data at 3 minutes of testing is the 24-hour viscosity test data. The results are shown in Table 3:

[0150] Table 3 Cathode slurry performance test results

[0151] Discharge viscosity mPa.s 24h slurry viscosity mPa.s Blank slurry 8880 34700 Slurry 1 5880 22250 Slurry 2 5740 19250 Slurry 3 5520 18300 Slurry 4 6100 21300 Slurry 5 7640 23800 Slurry 6 6320 24700 Slurry 7 5540 22700 Slurry 8 5640 20950 Slurry 9 8460 21460 Slurry 10 6120 19090

[0152] It can be seen from the test in Table 3 that compared with the blank slurry, the solid content of slurries 1-10 is increased from 58% to 62%, but the viscosity is lower than that of the blank slurry, indicating that the dispersing aid of the present invention can make the slurry with lower viscosity when having a higher solid content, indicating that the dispersing aid of the present invention has a dispersing effect of reducing viscosity and increasing the solid content of the slurry.

[0153] The above embodiments are only preferred implementation modes of the present invention and are only used to explain the present invention rather than to limit the present invention. Any changes, substitutions, modifications, etc. made by those skilled in the art without departing from the spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. A hyperbranched polymer, characterized in that The hyperbranched polymer is prepared by reacting compound A and compound B, wherein the reaction molar ratio of compound A to compound B is (1-1.2): (0.5-1); Wherein, compound A is one or more of citric acid, 1,2,3-cyclohexanetricarboxylic acid, isocitric acid, 3-phospho-1,3,5-pentanetricarboxylic acid, nitrilotriacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, benzotricarboxylic acid, 2-methylpropanetricarboxylic acid, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid and 1,2,4-butanetricarboxylic acid; Compound B is one or more of triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, tris(diaminoethyl)amine, the compound represented by the general structural formula (1), the compound represented by the general structural formula (2), the compound represented by the general structural formula (3) and the compound represented by the general structural formula (4); The general structural formula (1) is as follows: wherein n is an integer of 0-14, x is an integer of 1-34, y is an integer of 1-34, z is an integer of 1-34, 3≤x+y+z≤90, and R is -C2H5 or H; The general structural formula (2) is as follows: Wherein, x1 and y1 are each independently an integer between 0 and 56, and x1 and y1 are not 0 at the same time; The general structural formula (3) is as follows: Wherein: x2 and y2 are each independently an integer of 0-56; and x2 and y2 are not 0 at the same time, and R1 is methyl or ethyl; The structure of structural formula (4) is as follows:

2. The hyperbranched polymer according to claim 1, characterized in that The hyperbranched polymer meets one or more of the following conditions: (1) Compound A is citric acid, isocitric acid, 3-phospho-1,3,5-pentanetricarboxylic acid, nitrilotriacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, 2-methylpropanetricarboxylic acid, 1,2,4-benzenetricarboxylic acid or 1,2,4-butanetricarboxylic acid; (2) Compound B is triisopropanolamine, diethanol monoisopropanolamine, tris(diaminoethyl)amine, a compound represented by the general structural formula (1), a compound represented by the general structural formula (2), or a compound represented by the general structural formula (3); (3) The compound represented by the general structural formula (1) is a polyetheramine having a molecular weight of 400-6000; Preferably, the compound represented by the general structural formula (1) is a polyetheramine with a CAS number of 39423-51-3 and a molecular weight of 400-600 or a polyetheramine with a CAS number of 9046-10-0 and a molecular weight of 4000-6000; More preferably, the compound represented by the general structural formula (1) is Huntsman polyetheramine T403 or Huntsman polyetheramine T5000; (4) The compound represented by the general structural formula (2) is polyoxyethyl glyceryl ether with a molecular weight of 500-2000 or polyoxyethyl polyoxypropyl glyceryl ether with a molecular weight of 1000-6000; Preferably, the compound represented by the general structural formula (2) is a polyetheramine with a CAS number of 31694-55-0 and a molecular weight of 500-1500 or a polyetheramine with a CAS number of 9082-00-2 and a molecular weight of 3000-5000; More preferably, the compound represented by the general structural formula (2) is a polyetheramine with a CAS number of 31694-55-0 and a molecular weight of 900 or 1200 or a polyetheramine with a CAS number of 9082-00-2 and a molecular weight of 4000; and (5) the compound represented by the general structural formula (3) is trimethylolpropane polyoxyethylene ether with a molecular weight of 300-2000 or trimethylolpropane poly(oxypropylene) triether with a molecular weight of 200-1000; Preferably, the compound represented by the general structural formula (3) is trimethylolpropane polyoxyethylene ether with a CAS number of 50586-59-9 and a molecular weight of 500-1500 or trimethylolpropane poly(oxypropylene) triether with a CAS number of 25723-16-4 and a molecular weight of 200-8000; More preferably, the compound represented by the general structural formula (3) is trimethylolpropane polyoxyethylene ether with a CAS number of 50586-59-9 and a molecular weight of 1014 or trimethylolpropane poly(oxypropylene) triether with a CAS number of 25723-16-4 and a molecular weight of 308.

3. The hyperbranched polymer according to claim 1, characterized in that The hyperbranched polymer meets one or more of the following conditions: (1) In the general structural formula (1), n ​​is 0 or 1, x is an integer of 1-34, y is an integer of 1-34, z is an integer of 1-34, 3≤x+y+z≤90, and R is -C2H5 or H; Preferably, in the general structural formula (1), n ​​is 1, x, y and z are each independently an integer of 1-5, 3≤x+y+z≤10, and R is -C2H5; or, n is 0, x, y and z are each independently an integer of 20-34, 60≤x+y+z≤90, and R is H; More preferably, in the general structural formula (1), n ​​is 1, x, y and z are each independently an integer of 1-2, 5≤x+y+z≤6, and R is -C2H5; or, n is 0, x, y and z are each independently an integer of 26-30, 80≤x+y+z≤90, and R is H; (2) In the general structural formula (2), x1 is independently 0-30, y1 is independently 0-15, and 5≤x1+y1≤30; Preferably, in the general structural formula (2), x1 is independently 1-15, y1 is independently 0-10, and 5≤x1+y1≤15; More preferably, in the general structural formula (2), x1 is independently 6-12, and y1 is 0; or, x1 is independently 1-2, and y1 is 8-9; and (3) In the general structural formula (3), x2 is independently an integer of 2-10, y2 is 0, and R1 is methyl or ethyl; Preferably, in the general structural formula (3), x2 is independently an integer of 2-4, y2 is 0, and R1 is a methyl group; or, x2 is independently an integer of 6-8, y2 is 0, and R1 is an ethyl group.

4. The hyperbranched polymer according to claim 1, characterized in that The hyperbranched polymer satisfies any one of the following schemes 1-10: Scenario 1: Compound A is citric acid; Compound B is a polyetheramine with a CAS number of 39423-51-3 and a molecular weight of 440; Compound B is, for example, Huntsman T403; Scenario 2: Compound A is 3-phosphoryl-1,3,5-pentanetricarboxylic acid; Compound B is diethanol monoisopropanolamine; Scenario 3: Compound A is 2-phosphonobutane-1,2,4-tricarboxylic acid; Compound B is tris(diaminoethyl)amine; Solution 4: Compound A is 2-methylpropanetricarboxylic acid; Compound B is polyoxyethyl glycerol ether with CAS number 31694-55-0 and molecular weight 1200; Compound B is polyetheramine with merchant McLean product number G909231; Solution 5: Compound A is 1,2,4-benzenetricarboxylic acid; Compound B is trimethylolpropane polyoxyethylene ether with CAS number 50586-59-9 and molecular weight 1014; Solution 6: Compound A is isocitrate; Compound B is trimethylolpropane poly(oxypropylene) triether with CAS number 25723-16-4 and molecular weight 308; Solution 7: Compound A is 1,2,4-butanetricarboxylic acid; Compound B is polyoxyethyl polyoxypropyl glyceryl ether with CAS number 9082-00-2 and molecular weight 4000; Solution 8: Compound A is 2-methylpropanetricarboxylic acid; Compound B is a polyetheramine with a CAS number of 9046-10-0 and a molecular weight of 5000; Compound B is, for example, Huntsman T5000; Solution 9: Compound A is 2-phosphonobutane-1,2,4-tricarboxylic acid; Compound B is glycerol polyoxyethylene ether with CAS number 31694-55-0 and molecular weight 900; Solution 10: Compound A is nitrilotriacetic acid; Compound B is triisopropanolamine.

5. The hyperbranched polymer according to claim 1, characterized in that The hyperbranched polymer is prepared by reacting compound A and compound B, and the reaction satisfies one or more of the following conditions: (1) The reaction is carried out in the presence of N-methylpyrrolidone; Preferably, the total mass ratio of N-methylpyrrolidone and compound A to compound B is 1:0.5-3, preferably 1:1-2.5, such as 1:1 or 1:2; (2) The reaction is carried out at 80-120° C. under reduced pressure for 1-4 h, then at 125-160° C. under normal pressure for 2-6 h, and finally at 125-160° C. under reduced pressure for 2-6 h; (3) The reaction may further include a catalyst, wherein the catalyst is one or more of methanesulfonic acid, N,N,N,N,N-pentamethyldiethylenetriamine, triethylenediamine, dimethylaminopyridine, 4-pyrrolylpyridine, N,N-dicyclohexylcarbodiimide, diisopropylcarbodiimide, p-toluenesulfonic acid and 1-hydroxybenzotriazole; the catalyst is preferably 4-pyrrolylpyridine, triethylenediamine, methanesulfonic acid or 1-hydroxybenzotriazole; Preferably, the total mass ratio of the catalyst and compound A to compound B is 100:(0.1-5), preferably 100:(1-3); And (4) the reaction comprises the following steps: Step 1: In N-methylpyrrolidone, compound A and compound B are reacted at a temperature of 80 to 120° C. and a vacuum degree of -0.07 to -0.1 MPa for 1 to 6 hours; Step 2: react at a temperature of 125 to 160° C. and a pressure of normal pressure for 1 to 8 hours; Step 3: reacting for 1-8 hours at a temperature of 125-160° C. and a vacuum degree of -0.07-0.1 MPa to obtain the hyperbranched polymer.

6. A method for preparing a hyperbranched polymer as claimed in any one of claims 1 to 5, characterized in that: The steps include: Step 1: Compound A and Compound B react in N-methylpyrrolidone at a temperature of 80-120° C. under reduced pressure; Step 2: reacting at a temperature of 125-160°C and a pressure of normal pressure; Step 3: reacting at a temperature of 125-160° C. and under reduced pressure to obtain the hyperbranched polymer.

7. The method for preparing a hyperbranched polymer according to claim 6, wherein The reaction satisfies one or more of the following conditions: (1) The reaction molar ratio of compound A to compound B is 1:0.5-1.5; (2) the total mass ratio of N-methylpyrrolidone to compound A and compound B is 1:0.5-3, preferably 1:1-2.5, for example 1:1 or 1:2; (3) The reaction may further include a catalyst, wherein the catalyst is one or more of methanesulfonic acid, N,N,N,N,N-pentamethyldiethylenetriamine, triethylenediamine, dimethylaminopyridine, 4-pyrrolylpyridine, N,N-dicyclohexylcarbodiimide, diisopropylcarbodiimide, p-toluenesulfonic acid and 1-hydroxybenzotriazole; the catalyst is preferably 4-pyrrolylpyridine, triethylenediamine, methanesulfonic acid or 1-hydroxybenzotriazole; Preferably, the total mass ratio of the catalyst and compound A to compound B is 100:(0.1-5), preferably 100:(1-3); (4) In step 1, the temperature is 80, 58, 90, 95, 100, 105, 110, 115 or 120° C.; (5) In step 1, the pressure of the reduced pressure is -0.07 to -0.1 MPa, preferably -0.08 to -0.095 MPa, for example, 0.08 to -0.083 MPa, -0.08 to -0.085 MPa, -0.082 to -0.085 MPa, -0.085 to -0.087 MPa, -0.088 to -0.090 MPa or -0.092 to -0.095 MPa; (6) In step 1, the reaction time is 1-6 h, preferably 1-4 h, for example 1, 2, 3 or 4 h; (7) In step 2, the temperature is 150-160° C., for example, 150, 155 or 160° C.; (8) In step 2, the reaction time is 1-8 h, preferably 2-6 h, for example 2, 3, 4, 5 or 6 h; (9) In step 3, the temperature is 140-160° C., for example, 140, 150 or 155° C.; (10) In step 3, the pressure of the decompression is -0.07 to -0.1 MPa, preferably -0.085 to -0.01 MPa, for example -0.09 to -0.092 MPa or -0.093 to -0.095 MPa; (11) In step 3, the reaction time is 1-8 h, preferably 2-6 h, for example 2, 3, 4, 5 or 6 h; After the reaction of step (12) 3 is completed, the method further comprises the step of diluting the mixture with N-methylpyrrolidone; preferably, the dilution step comprises adding N-methylpyrrolidone to dilute the mixture to a solid content of 45-55%, preferably 50%.

8. The method for preparing a hyperbranched polymer according to claim 6, wherein The reaction comprises the following steps: Step 1: In N-methylpyrrolidone, compound A and compound B are reacted at a temperature of 90 to 120°C and a pressure of -0.08 to -0.095 MPa for 1 to 4 hours; Step 2: react at a temperature of 140-160°C and a pressure of normal pressure for 2-6 hours; Step 3: reacting for 2-6 hours at a temperature of 140-160° C. and a pressure of -0.085-0.01 MPa, and diluting with N-methylpyrrolidone to a solid content of 45-55% to obtain the hyperbranched polymer.

9. A hyperbranched polymer, characterized in that The hyperbranched polymer is prepared by the method for preparing a hyperbranched polymer according to any one of claims 6 to 8.

10. Use of the hyperbranched polymer according to claims 1 to 5, or the hyperbranched polymer according to claim 9 as a dispersant in a positive electrode slurry.

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