A bio-based lithium battery negative electrode binder, its preparation method and application

Abstract

This invention provides a bio-based lithium-ion battery negative electrode adhesive, its preparation method, and its application. This invention belongs to the technical field of polymer materials for batteries. The raw materials for preparing the bio-based lithium-ion battery negative electrode adhesive include diisocyanate, macromolecular chain extender, small molecule chain extender, unsaturated end-capping agent, organic solvent, water, initiator, and amine neutralizer. The macromolecular chain extender is at least one of bio-based polyester polyol or polyether polyol, and the small molecule chain extender includes dimethylolpropionic acid. The bio-based lithium-ion battery negative electrode adhesive material of this invention has strong solvent and corrosion resistance properties, and can withstand long-term immersion in strong electrolytes without dissolving, with controllable swelling rate.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology for batteries, and relates to a bio-based lithium battery negative electrode adhesive, its preparation method and application. Background Technology

[0002] With the increasing popularity of electric vehicles and portable devices, higher demands are being placed on the fast-charging performance of lithium batteries. During fast charging, the rapid insertion and extraction of lithium ions can lead to volume changes in electrode materials, thereby affecting the stability and lifespan of the battery.

[0003] Under fast charging conditions, electrode materials and separators need to possess good chemical stability and mechanical strength to prevent structural damage and performance degradation caused by swelling. The swelling properties of the binder also affect the structural stability of the electrode. By testing the swelling rate of the binder in the electrolyte, high-performance binders suitable for fast-charging batteries can be screened.

[0004] With ever-increasing performance requirements, existing negative electrode binders cannot meet the higher charge-discharge performance demands. At the same time, the new era also presents more environmental protection requirements, making the development of bio-based materials, whose main materials are derived from renewable sources, a key research focus in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a bio-based lithium battery negative electrode adhesive, its preparation method, and its application. The bio-based lithium battery negative electrode adhesive material of the present invention exhibits strong solvent and corrosion resistance, and can withstand prolonged immersion in strong electrolytes without dissolving, with controllable swelling rate.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] On one hand, the present invention provides a bio-based lithium battery negative electrode adhesive, wherein the raw materials for preparing the bio-based lithium battery negative electrode adhesive include diisocyanate, macromolecular chain extender, small molecule chain extender, unsaturated end-capping agent, organic solvent, water, initiator and amine neutralizer, wherein the macromolecular chain extender is at least one of bio-based polyester polyol or polyether polyol, and the small molecule chain extender includes dimethylolpropionic acid.

[0008] In this invention, the bio-based lithium battery negative electrode adhesive material prepared using the raw materials described above has strong solvent and corrosion resistance properties, and can be immersed in strong electrolytes for a long time without dissolving, and the swelling rate is controllable.

[0009] Preferably, the diisocyanate is a bio-based diisocyanate.

[0010] Preferably, the bio-based diisocyanate is selected from any one or a combination of at least two of pentamethylene diisocyanate (PDI), lysine diisocyanate (LDI), or 2,5-furan diisocyanate.

[0011] Preferably, the macromolecular chain extender is selected from any one or a combination of at least two of polytrimethylene ether glycol (PO3G), polycaprolactone (PCL), castor oil-modified polyol, or polytetramethylene ether glycol (PTMEG).

[0012] Preferably, the number-average molecular weight of the macromolecular chain extender is 1000-3000, for example 1000, 1200, 1500, 1800, 2000, 2300, 2500, 2800 or 3000, preferably 2000. In this invention, if the number-average molecular weight of the macromolecular chain extender is less than 1000, the final prepared material will have too low a molecular weight and poor strength, and will dissolve when immersed in the electrolyte. If the number-average molecular weight of the macromolecular chain extender is greater than 3000, the material will have insufficient strength.

[0013] Preferably, the unsaturated end-capping agent is selected from any one or a combination of at least two of hydroxyethyl methacrylate, hydroxyethyl acrylate, or hydroxypropyl acrylate.

[0014] Preferably, the organic solvent is selected from any one or a combination of at least two of acetone, butanone, or N-methylpyrrolidone.

[0015] Preferably, the initiator is selected from azobisisobutyronitrile (AIBN) or benzoyl peroxide (BPO).

[0016] Preferably, the amine neutralizing agent is selected from triethylamine and / or AMP-95.

[0017] Preferably, the molar ratio of diisocyanate to macromolecular chain extender in the raw materials is 1:0.85-0.92, for example, 1:0.85, 1:0.86, 1:0.88, 1:0.90 or 1:0.92.

[0018] Preferably, the molar ratio of diisocyanate to dimethylolpropionic acid in the raw materials is 1:0.02-0.04, for example, 1:0.02, 1:0.03 or 1:0.04.

[0019] Preferably, the small molecule chain extender may also include any one or a combination of at least two of other small molecule diols or small molecule diamines.

[0020] Preferably, the other small molecule diols are selected from ethylene glycol and / or 1,4-butanediol;

[0021] Preferably, the small molecule diamine includes ethylenediamine.

[0022] Preferably, the molar ratio of other small molecule diols to diisocyanates in the raw materials is 0.05-0.13:1, such as 0.05:1, 0.06:1, 0.08:1, 0.10:1, 0.12:1 or 0.13:1.

[0023] Preferably, the molar ratio of diisocyanate to unsaturated capping agent in the raw materials is 1:0.03-0.08, for example, 1:0.03, 1:0.04, 1:0.05, 1:0.06, 1:0.07 or 1:0.08.

[0024] Preferably, the amount of organic solvent used in the raw materials is 10-30% of the total mass of diisocyanate, for example, 10%, 15%, 18%, 20%, 23%, 25%, 28% or 30%.

[0025] Preferably, the amount of water used in the raw materials is 180-300% of the total mass of the diisocyanate, for example, 180%, 200%, 220%, 230%, 250%, 280% or 300%.

[0026] Preferably, the amount of initiator in the raw materials is 0.3-0.8% of the total mass of diisocyanate and unsaturated capping agent, for example, 0.3%, 0.4%, 0.5%, 0.6%, 0.7% or 0.8%.

[0027] Preferably, the amount of the amine neutralizing agent used in the preparation is 0.1-0.3% of the total mass of the preparation raw materials, for example, 0.1%, 0.13%, 0.15%, 0.18%, 0.2%, 0.25%, 0.28% or 0.3%.

[0028] On the other hand, the present invention provides a method for preparing the bio-based lithium battery negative electrode binder as described above, the preparation method comprising the following steps:

[0029] (1) The diisocyanate is reacted with an unsaturated end-capping agent to obtain a diisocyanate with partially unsaturated bonds;

[0030] (2) The diisocyanate with partially unsaturated bonds and the macromolecular chain extender are reacted under the initiation of an initiator;

[0031] (3) Add an organic solvent to the reaction system obtained in step (2), and then add a small molecule chain extender. React until the viscosity no longer increases.

[0032] (4) Add the reaction solution obtained in step (3) to water, and at the same time use an amine neutralizing agent to adjust the pH and remove the organic solvent;

[0033] (5) The solid content of the system is adjusted by water to obtain the bio-based lithium battery negative electrode binder.

[0034] Preferably, the reaction temperature in step (1) is 30-70°C, for example 30°C, 40°C, 50°C, 55°C, 60°C, 65°C or 70°C, preferably 50-70°C, and the reaction time is 1-6h, for example 1h, 2h, 3h, 4h, 4.5h, 5h, 5.5h or 6h, preferably 4-6h.

[0035] Preferably, the temperature of the reaction in step (2) is 80-90℃, for example 80℃, 83℃, 85℃, 88℃ or 90℃, and the reaction time is 6-10h, for example 6h, 7h, 8h, 9h or 10h.

[0036] In this invention, the reaction in step (2) must be isolated from water vapor.

[0037] Preferably, the reaction temperature in step (3) is 80-90°C, for example 80°C, 85°C, 88°C or 90°C.

[0038] Preferably, the amount of water used in step (4) accounts for 50-60% of the total mass of the reaction solution and water, for example, 50%, 53%, 55%, 58% or 60%.

[0039] Preferably, step (4) involves adjusting the pH to 7-9 using an amine neutralizing agent, for example, 7, 7.2, 7.4, 7.6, 7.8, 8, 8.3, 8.5, 8.8, or 9.

[0040] Preferably, the removal of organic solvent in step (4) can be achieved by rotary evaporation.

[0041] Preferably, the solid content in step (5) is 35-40%, for example 35%, 36%, 37%, 38%, 39% or 40%.

[0042] On the other hand, the present invention provides a lithium battery negative electrode, the lithium battery negative electrode comprising the bio-based lithium battery negative electrode binder as described above.

[0043] On the other hand, the present invention provides a bio-based lithium battery, the bio-based lithium battery comprising a lithium battery negative electrode as described above.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The bio-based lithium battery negative electrode binder material of the present invention has strong solvent resistance and corrosion resistance. It can be immersed in strong electrolyte for a long time without dissolving, and the swelling rate is controllable. It can be applied to lithium batteries to meet the requirements of high-speed charging applications. Attached Figure Description

[0046] Figure 1 The infrared spectrum of the product obtained in step (1) of Example 1 is shown.

[0047] Figure 2 The infrared spectrum of the product obtained in step (5) of Example 1 is shown. Detailed Implementation

[0048] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0049] Example 1

[0050] This embodiment provides a bio-based lithium battery negative electrode adhesive, the preparation method of which includes the following steps:

[0051] (1) Pentamethylene diisocyanate and unsaturated end-capping agent hydroxyethyl methacrylate were reacted at 50°C for 3 h in a molar ratio of 1:0.05 to obtain diisocyanate with partially unsaturated bonds.

[0052] (2) The diisocyanate with partially unsaturated bonds obtained in step (1) and the macromolecular chain extender polytrimethylene ether glycol (number average molecular weight of 2000, SK Korea) were reacted at 80°C with a molar ratio of 1:0.85, and the reaction was initiated by AIBN (the amount of initiator was 0.3% of the total mass of diisocyanate and unsaturated end-capping agent). The reaction was carried out for 8 hours, and water vapor had to be isolated during the reaction.

[0053] (3) Add organic solvent acetone (the amount of acetone added is 20% of the mass of pentamethylene diisocyanate) to the reaction system obtained in step (2), and then add small molecule chain extender dimethylolpropionic acid (the molar ratio of dimethylolpropionic acid to pentamethylene diisocyanate is 0.03:1), and react at 80°C until the viscosity no longer increases.

[0054] (4) Add the reaction solution obtained in step (3) to water, the amount of water is 50% of the total mass of the reaction solution and water, and at the same time adjust the pH to 8 using the amine neutralizing agent triethylamine, and remove the organic solvent by rotary evaporation.

[0055] (5) Add water to adjust the solid content of the system to 40% to obtain the bio-based lithium battery negative electrode adhesive.

[0056] The infrared spectrum of the product obtained in step (1) of this embodiment is as follows: Figure 1 As shown, in the range of 2100-2400cm -1 The characteristic absorption peak of "-NCO" is... Figure 2 The infrared spectrum of the product obtained in step (5) is shown, with values ​​in the range of 2100-2400 cm⁻¹.-1 The characteristic absorption peak of "-NCO" almost disappeared.

[0057] Example 2

[0058] This embodiment provides a bio-based lithium battery negative electrode adhesive, the preparation method of which includes the following steps:

[0059] (1) Pentamethylene diisocyanate and unsaturated end-capping agent hydroxyethyl methacrylate were reacted at 70 °C for 4 h in a molar ratio of 1:0.08 to obtain diisocyanate with partially unsaturated bonds.

[0060] (2) The diisocyanate with partially unsaturated bonds obtained in step (1) and the macromolecular chain extender polycaprolactone (number average molecular weight of 2000, Daicel, Japan) were reacted at 85°C with a molar ratio of 1:0.85, and the reaction was initiated by BPO (the amount of initiator was 0.3% of the total mass of diisocyanate and unsaturated end-capping agent). The reaction was carried out for 8 hours, and water vapor had to be isolated during the reaction.

[0061] (3) Add the organic solvent butanone (the amount of butanone added is 10% of the mass of pentamethylene diisocyanate) to the reaction system obtained in step (2), and then add the small molecule chain extender dimethylolpropionic acid (the molar ratio of dimethylolpropionic acid to pentamethylene diisocyanate is 0.04:1), and react at 85°C until the viscosity no longer increases.

[0062] (4) Add the reaction solution obtained in step (3) to water, the amount of water is 50% of the total mass of the reaction solution and water, and at the same time adjust the pH to 8.5 using the amine neutralizing agent triethylamine, and remove the organic solvent by rotary evaporation.

[0063] (5) Add water to adjust the solid content of the system to 40% to obtain the bio-based lithium battery negative electrode adhesive.

[0064] Example 3

[0065] This embodiment provides a bio-based lithium battery negative electrode adhesive, the preparation method of which includes the following steps:

[0066] (1) Pentamethylene diisocyanate and unsaturated end-capping agent hydroxyethyl methacrylate were reacted at 60 °C for 5 h in a molar ratio of 1:0.04 to obtain diisocyanate with partially unsaturated bonds.

[0067] (2) The diisocyanate with partially unsaturated bonds obtained in step (1) and the macromolecular chain extender castor oil modified polyol (number average molecular weight of 2000, Vantrus, USA) were reacted at 90°C with a molar ratio of 1:0.9, and the reaction was initiated by BPO (the amount of initiator was 0.5% of the total mass of diisocyanate and unsaturated end-capping agent). The reaction was carried out for 8 hours, and water vapor had to be isolated during the reaction.

[0068] (3) Add the organic solvent butanone (the amount of butanone added is 30% of the mass of pentamethylene diisocyanate) to the reaction system obtained in step (2), and then add the small molecule chain extender dimethylolpropionic acid (the molar ratio of dimethylolpropionic acid to pentamethylene diisocyanate is 0.02:1), and react at 80°C until the viscosity no longer increases.

[0069] (4) Add the reaction solution obtained in step (3) to water, the amount of water is 50% of the total mass of the reaction solution and water, and at the same time adjust the pH to 7.4 using the amine neutralizing agent triethylamine, and remove the organic solvent by rotary evaporation.

[0070] (5) Add water to adjust the solid content of the system to 40% to obtain the bio-based lithium battery negative electrode adhesive.

[0071] Example 4

[0072] This embodiment provides a bio-based lithium battery negative electrode adhesive, the preparation method of which includes the following steps:

[0073] (1) Pentamethylene diisocyanate and unsaturated end-capping agent hydroxyethyl methacrylate were reacted at 40 °C for 6 h in a molar ratio of 1:0.03 to obtain diisocyanate with partially unsaturated bonds.

[0074] (2) The diisocyanate with partially unsaturated bonds obtained in step (1) and the macromolecular chain extender polytetramethylene ether glycol (number average molecular weight of 2000, Hyosung, South Korea) were reacted at 90°C with a molar ratio of 1:0.92, and the reaction was initiated by AIBN (the amount of initiator was 0.7% of the total mass of diisocyanate and unsaturated end-capping agent). The reaction was carried out for 10 hours, and water vapor had to be isolated during the reaction.

[0075] (3) Add the organic solvent butanone (the amount of butanone added is 15% of the mass of pentamethylene diisocyanate) to the reaction system obtained in step (2), and then add the small molecule chain extender dimethylolpropionic acid (the molar ratio of dimethylolpropionic acid to pentamethylene diisocyanate is 0.03:1), and react at 90°C until the viscosity no longer increases.

[0076] (4) Add the reaction solution obtained in step (3) to water, the amount of water is 50% of the total mass of the reaction solution and water, and at the same time adjust the pH to weak alkalinity using amine neutralizer AMP-95, and remove the organic solvent by rotary evaporation.

[0077] (5) Add water to adjust the solid content of the system to 40% to obtain the bio-based lithium battery negative electrode adhesive.

[0078] Example 5

[0079] This embodiment provides a bio-based lithium battery negative electrode adhesive, the preparation method of which includes the following steps:

[0080] (1) Pentamethylene diisocyanate and unsaturated end-capping agent hydroxyethyl methacrylate were reacted at 30°C for 6 h in a molar ratio of 1:0.03 to obtain diisocyanate with partially unsaturated bonds.

[0081] (2) The diisocyanate with partially unsaturated bonds obtained in step (1) and the macromolecular chain extender polytrimethylene ether glycol (weight average molecular weight of 2000) were reacted at 80°C with a molar ratio of 1:0.85, and the reaction was initiated by AIBN (the amount of initiator was 0.8% of the total mass of diisocyanate and unsaturated end-capping agent). The reaction was carried out for 9 hours, and water vapor had to be isolated during the reaction.

[0082] (3) Add the organic solvent acetone (the amount of methyl ethyl ketone added is 25% of the mass of pentamethylene diisocyanate) to the reaction system obtained in step (2), and then add the small molecule chain extender dimethylolpropionic acid (the molar ratio of dimethylolpropionic acid to pentamethylene diisocyanate is 0.03:1) and ethylene glycol (the molar ratio of ethylene glycol to pentamethylene diisocyanate is 0.05:1), and react at 85°C until the viscosity no longer increases;

[0083] (4) Add the reaction solution obtained in step (3) to water, the amount of water is 50% of the total mass of the reaction solution and water, and at the same time adjust the pH to 8 using the amine neutralizing agent triethylamine, and remove the organic solvent by rotary evaporation.

[0084] (5) Add water to adjust the solid content of the system to 40% to obtain the bio-based lithium battery negative electrode adhesive.

[0085] Example 6

[0086] This embodiment provides a bio-based lithium battery negative electrode adhesive, the preparation method of which includes the following steps:

[0087] (1) Lysine diisocyanate and unsaturated end-capping agent hydroxyethyl methacrylate were reacted at 60 °C for 3 h in a molar ratio of 1:0.03 to obtain diisocyanate with partially unsaturated bonds.

[0088] (2) The diisocyanate with partially unsaturated bonds obtained in step (1) and the macromolecular chain extender polytrimethylene ether glycol (number average molecular weight of 2000, SK Korea) were reacted at 90°C with a molar ratio of 1:0.88, and the reaction was initiated by AIBN (the amount of initiator was 0.5% of the total mass of diisocyanate and unsaturated end-capping agent). The reaction was carried out for 8 hours, and water vapor had to be isolated during the reaction.

[0089] (3) Add the organic solvent N-methylpyrrolidone (the amount of N-methylpyrrolidone added is 20% of the mass of lysine diisocyanate) to the reaction system obtained in step (2), and then add the small molecule chain extender dimethylolpropionic acid (the molar ratio of dimethylolpropionic acid to lysine diisocyanate is 0.02:1) and 1,4-butanediol (the molar ratio of 1,4-butanediol to lysine diisocyanate is 0.05:1), and react at 80°C until the viscosity no longer increases;

[0090] (4) Add the reaction solution obtained in step (3) to water, the amount of water is 50% of the total mass of the reaction solution and water, and at the same time adjust the pH to 7 using the amine neutralizing agent triethylamine, and remove the organic solvent by rotary evaporation.

[0091] (5) Add water to adjust the solid content of the system to 40% to obtain the bio-based lithium battery negative electrode adhesive.

[0092] Example 7

[0093] This embodiment provides a bio-based lithium battery negative electrode adhesive, the preparation method of which includes the following steps:

[0094] (1) 2,5-furan diisocyanate and unsaturated end-capping agent hydroxyethyl acrylate were reacted at 60 °C for 5 h in a molar ratio of 1:0.05 to obtain diisocyanate with partially unsaturated bonds.

[0095] (2) The diisocyanate with partially unsaturated bonds obtained in step (1) and the macromolecular chain extender polycaprolactone (number average molecular weight of 2000, Daicel, Japan) were reacted at 90°C with a molar ratio of 1:0.92, and the reaction was initiated by BPO (the amount of initiator was 0.8% of the total mass of diisocyanate and unsaturated end-capping agent). The reaction was carried out for 7 hours, and water vapor had to be isolated during the reaction.

[0096] (3) Add the organic solvent N-methylpyrrolidone (the amount of N-methylpyrrolidone added is 10% of the mass of 2,5-furan diisocyanate) to the reaction system obtained in step (2), and then add the small molecule chain extender dimethylolpropionic acid (the molar ratio of dimethylolpropionic acid to 2,5-furan diisocyanate is 0.04:1) and ethylene glycol (the molar ratio of ethylene glycol to 2,5-furan diisocyanate is 0.13:1), and react at 90°C until the viscosity no longer increases;

[0097] (4) Add the reaction solution obtained in step (3) to water, the amount of water is 50% of the total mass of the reaction solution and water, and at the same time adjust the pH to 9 using the amine neutralizing agent triethylamine, and remove the organic solvent by rotary evaporation.

[0098] (5) Add water to adjust the solid content of the system to 40% to obtain the bio-based lithium battery negative electrode adhesive.

[0099] Example 8

[0100] This embodiment provides a bio-based lithium battery negative electrode adhesive, the preparation method of which includes the following steps:

[0101] (1) Pentamethylene diisocyanate and unsaturated end-capping agent hydroxypropyl acrylate were reacted at 70 °C for 4 h in a molar ratio of 1:0.03 to obtain diisocyanate with partially unsaturated bonds.

[0102] (2) The diisocyanate with partially unsaturated bonds obtained in step (1) and the macromolecular chain extender polycaprolactone (number average molecular weight of 2000, Daicel, Japan) were reacted at 85°C with a molar ratio of 1:0.85, and the reaction was initiated by AIBN (the amount of initiator was 0.3% of the total mass of diisocyanate and unsaturated end-capping agent). The reaction was carried out for 7 hours, and water vapor had to be isolated during the reaction.

[0103] (3) Add the organic solvent N-methylpyrrolidone (the amount of N-methylpyrrolidone added is 30% of the mass of pentamethylene diisocyanate) to the reaction system obtained in step (2), and then add the small molecule chain extender dimethylolpropionic acid (the molar ratio of dimethylolpropionic acid to pentamethylene diisocyanate is 0.02:1) and ethylenediamine (the molar ratio of ethylenediamine to pentamethylene diisocyanate is 0.08:1), and react at 85°C until the viscosity no longer increases;

[0104] (4) Add the reaction solution obtained in step (3) to water, the amount of water is 50% of the total mass of the reaction solution and water, and at the same time adjust the pH to 9 using the amine neutralizing agent triethylamine, and remove the organic solvent by rotary evaporation.

[0105] (5) Add water to adjust the solid content of the system to 40% to obtain the bio-based lithium battery negative electrode adhesive.

[0106] Example 9

[0107] The only difference from Example 1 is that the macromolecular chain extender polytrimethylene ether glycol has a weight-average molecular weight of 1000 (purchased from SK Korea).

[0108] Example 10

[0109] The only difference from Example 1 is that the number average molecular weight of the macromolecular chain extender polytetramethylene ether glycol is 3000 (purchased from Hyosung, South Korea).

[0110] Comparative Example 1

[0111] The only difference from Example 1 is that no initiator is added in step (2).

[0112] Comparative Example 2

[0113] The only difference from Example 1 is that the macromolecular chain extender in step (2) is replaced with an equimolar amount of polycarbonate diol with a molecular weight of 2000, purchased from Ube Industries, Ltd., Japan.

[0114] Comparative Example 3

[0115] The only difference from Example 4 is that in step (2), the macromolecular chain extender is replaced with an equimolar amount of polytetramethylene ether glycol (number average molecular weight of 3500, Hyosung, South Korea).

[0116] Comparative Example 4

[0117] The only difference from Example 1 is that in step (2), the macromolecular chain extender is replaced with an equimolar amount of polytrimethylene ether glycol (number average molecular weight of 600, SK Korea).

[0118] After drying the adhesive materials prepared in the examples and comparative examples, square films with a length, width, and thickness of 10 mm × 10 mm × 50 μm were prepared. These films were then immersed in the electrolyte of a 3C battery for 4 hours in the dark, and then removed to test the dissolution and deformation rate.

[0119] Dissolution: Record the initial mass m1 of the square membrane. After soaking in the electrolyte (EC (ethylene carbonate): EMC (ethyl methyl carbonate): DMC (dimethyl carbonate) = 3:5:2) for 4 hours, remove it and dry it in a 70℃ oven until constant weight. Weigh it and measure the mass m2. Test the weight loss rate [1-(m1-m2) / m1]×100%.

[0120] Deformation rate: Length × Width after testing / (Initial Length × Width) × 100%.

[0121] The test results are shown in Table 1.

[0122] Table 1

[0123] Solubility Deformation rate Example 1 93.7％ 36％ Example 2 91.6％ 35％ Example 3 95.2％ 29％ Example 4 89.3％ 31％ Example 5 92.6％ 33％ Example 6 91.7％ 36％ Example 7 88.2％ 33％ Example 8 89.5％ 31％ Example 9 81.9％ 48％ Example 10 88.7％ 39％ Comparative Example 1 Completely dissolved NA Comparative Example 2 Completely dissolved NA Comparative Example 3 79.7％ 52％ Comparative Example 4 78.6％ 66％

[0124] The comparative polyurethanes all dissolved in the system. The deformation rate of this product is within 48%.

[0125] The reason for this is that the adhesive material of the present invention contains a large number of conventional alkane segments, which have strong solvent resistance and corrosion resistance. Secondly, unsaturated bonds are introduced into the main chain segments, and after the double bonds are cross-linked by additives such as AIBN, its solvent resistance is further improved, so that it will not dissolve even after long-term immersion in strong electrolytes, and the swelling rate can also be controlled.

[0126] The applicant declares that this invention illustrates the bio-based lithium battery negative electrode adhesive, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection and disclosure scope of this invention.

Claims

1. Use of a bio-based lithium battery anode binder in a lithium battery anode, characterized in that, The preparation raw materials of the bio-based lithium battery negative electrode adhesive include diisocyanate, a macromolecular chain extender, a small molecule chain extender, an unsaturated capping agent, an organic solvent, water, an initiator, and an amine neutralizer, wherein the macromolecular chain extender is at least one of polycaprolactone, castor oil modified polyol, or polyether polyol, and the small molecule chain extender includes dimethylol propionic acid; The number average molecular weight of the macromolecular chain extender is 1000-3000; The molar ratio of diisocyanate to the unsaturated capping agent in the preparation raw materials is 1:0.03-0.08; The molar ratio of diisocyanate to the macromolecular chain extender in the preparation raw materials is 1:0.85-0.92; The bio-based lithium battery negative electrode adhesive is prepared by the following preparation method, which includes the following steps: (1) reacting diisocyanate and an unsaturated capping agent to obtain diisocyanate with partial unsaturated bonds; (2) reacting diisocyanate with partial unsaturated bonds and a macromolecular chain extender under the initiation of an initiator; (3) adding an organic solvent to the reaction system obtained in step (2), and then adding a small molecule chain extender, and reacting until the viscosity no longer increases; (4) adding the reaction solution obtained in step (3) to water, adjusting the pH by using an amine neutralizer, and removing the organic solvent; (5) adjusting the solid content of the system by using water to obtain the bio-based lithium battery negative electrode adhesive.

2. Use according to claim 1, characterized in that, The diisocyanate is a bio-based diisocyanate.

3. Use according to claim 2, characterized in that, The bio-based diisocyanate is selected from any one or a combination of at least two of pentamethylene diisocyanate, lysine diisocyanate, or 2,5-furan diisocyanate.

4. Use according to claim 1, characterized in that, The macromolecular chain extender is selected from any one or a combination of at least two of polytrimethylene ether glycol and / or polytetramethylene ether glycol.

5. The use according to claim 1, characterized in that, The number average molecular weight of the macromolecular chain extender is 2000.

6. Use according to claim 1, characterized in that, The unsaturated capping agent is selected from any one or a combination of at least two of hydroxyethyl methacrylate, hydroxyethyl acrylate, or hydroxypropyl acrylate.

7. Use according to claim 1, characterized in that, The organic solvent is selected from any one or a combination of at least two of acetone, butanone, or azomethyl pyrrolidone.

8. The use according to claim 1, characterized in that, The initiator is selected from azobisisobutyronitrile or dibenzoyl peroxide.

9. The use according to claim 1, characterized in that, The amine neutralizer is selected from triethylamine and / or AMP-95.

10. The use according to claim 1, characterized in that, The molar ratio of diisocyanate to dimethylol propionic acid in the preparation raw materials is 1:0.02-0.

04.

11. Use according to claim 1, characterized in that, The small molecule chain extender further includes any one or a combination of at least two of other small molecule diols or diamines.

12. Use according to claim 11, characterized in that, The other small molecule diols are selected from ethylene glycol and / or 1,4-butanediol, and the small molecule diamines include ethylenediamine.

13. The use according to claim 11, characterized in that, The molar ratio of the other small molecule diols or diamines to diisocyanate in the preparation raw materials is 0.05-0.13:

1.

14. The use according to claim 1, characterized in that, The amount of the organic solvent in the preparation raw materials is 10-30% of the mass of diisocyanate.

15. The use according to claim 1, characterized in that, The amount of water in the preparation raw materials is an amount that makes the solid content of the bio-based lithium battery negative electrode adhesive 35-40%.

16. The use according to claim 1, characterized in that, The amount of the initiator in the preparation raw materials is 0.3-0.8% of the total mass of diisocyanate and the unsaturated capping agent.

17. The use according to claim 1, characterized in that, The amount of the amine neutralizer used in the preparation of the raw material is 0.1-0.3% of the total mass of the raw material.

18. The use according to claim 1, characterized in that, The temperature of the reaction in step (1) is 30-70℃, and the reaction time is 1-6h.

19. The use according to claim 1, characterized in that, The temperature of the reaction in step (2) is 80-90℃, and the reaction time is 6-10h.

20. The use according to claim 1, characterized in that, The temperature of the reaction in step (3) is 80-90℃.

21. The use according to claim 1, characterized in that, The amount of water used in step (4) is 50-60% of the total mass of the reaction liquid and water.

22. The use according to claim 1, characterized in that, The pH is adjusted to 7-9 in step (4) using the amine neutralizer.

23. The use according to claim 1, characterized in that, The removal of the organic solvent in step (4) is achieved using rotary evaporation.

24. The use according to claim 1, characterized in that, The solid content in step (5) is 30-40%.

25. A lithium battery anode, characterized by, The lithium battery negative electrode comprises the bio-based lithium battery negative electrode adhesive of any one of claims 1-24.

26. A biobased lithium battery, characterized in that, The bio-based lithium battery comprises the lithium battery negative electrode of claim 25.

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