CN-122000357-A - Pore-forming agent for lithium ion battery and preparation method and application thereof

CN122000357ACN 122000357 ACN122000357 ACN 122000357ACN-122000357-A

Abstract

The invention provides a pore-forming agent for a lithium ion battery and a preparation method thereof, comprises a step of preparing a wall material, a step of preparing a core material, a step of preparing W/O type colostrum and a step of preparing a pore-forming agent for a lithium ion battery. The method for preparing the pore-forming agent is a novel synthetic route of the pore-forming agent and has the advantages of simple reaction steps, mild reaction conditions, high yield, low cost, environmental protection and the like. According to the technology, a pore-forming agent is introduced into the electrode, so that a uniform multi-stage pore network can be accurately constructed, and the charge transmission impedance is obviously reduced, thereby effectively improving the quick charge capacity and high-rate discharge performance of the battery, greatly improving the electrode-electrolyte interface contact, and ensuring the full utilization of an active material. The invention also provides application of the pore-forming agent for the lithium ion battery to the lithium ion battery, and the pore-forming agent for the lithium ion battery is applied to the lithium ion battery, so that the ion conduction can be improved, and the multiplying power performance can be improved.

Inventors

LI QIANG
XIANG XIAOYUE
HE QIULING
Li Bigao
QIU XIAOJING
LI TIANCI

Assignees

深圳市钰联新材料科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260408

Claims (10)

1. The preparation method of the pore-forming agent for the lithium ion battery is characterized by comprising the following steps of: Preparing a wall material, namely providing 2500-3500 parts of deionized water, 250-300 parts of cyanamide oligomer, 250-300 parts of urea compound and 800-1200 parts of lower aliphatic aldehyde, uniformly mixing the deionized water, the cyanamide oligomer, the urea compound and the lower aliphatic aldehyde, transferring the mixture into a first reaction kettle, regulating the pH value of the mixed solution in the first reaction kettle to 8.5-9, heating the first reaction kettle to 65-75 ℃ and maintaining the temperature for 0.5-1.5 h, continuously adding 10000-15000 parts of deionized water into the first reaction kettle after the reaction is finished, continuously stirring for 0.5-2 h, and standing for 0.5-1.5 h to obtain the wall material; Preparing a core material, namely providing 500-1000 parts of deionized water, 250-300 parts of aliphatic polyester and 10-30 parts of cosolvent, uniformly mixing the deionized water, polylactic acid and the cosolvent, and then filtering the mixture to obtain a water phase core material; Providing 30-50 parts of oil phase additive, 1-10 parts of emulsifier and 1-5 parts of defoamer, adding the oil phase additive, the emulsifier and the defoamer into a second reaction kettle, and uniformly mixing to obtain an oil phase emulsifier; the pore-forming agent for the lithium ion battery is prepared by dropwise adding a wall material into W/O type colostrum under the condition of stirring the W/O type colostrum, adjusting the pH value of a mixed system to 4-5 after the dropwise adding, continuously stirring for 0.1-0.5 h, heating a second reaction kettle to 70-80 ℃ and maintaining for 1-5 h to obtain emulsion, and washing, drying and crushing the emulsion to obtain TM microcapsule, namely the pore-forming agent for the lithium ion battery.
2. The method for producing a pore-forming agent for lithium ion batteries according to claim 1, wherein in the step of producing a wall material, the melamine oligomer is at least one of melamine, dicyandiamide and thiodicyandiamide, the urea compound is at least one of urea, thiourea, methyl urea and 1, 1-dimethylurea, and the lower aliphatic aldehyde is at least one of formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde and valeraldehyde.
3. The method for preparing a pore-forming agent for a lithium ion battery according to claim 1, wherein in the step of preparing a wall material, the specific operation of adjusting the pH value of the mixed solution in the first reaction kettle to 8.5-9 is that an alkalinity regulator is added into the mixed solution while stirring the mixed solution until the pH value reaches 8.5-9; The alkalinity regulator is at least one of triethanolamine solution, ethanolamine solution, sodium bicarbonate solution and sodium hydroxide solution.
4. The method for producing a pore-forming agent for lithium ion batteries according to claim 1, wherein in the step of producing a core material, the aliphatic polyester is any one of polylactic acid, polyglycolic acid, polydextrose polylactic acid and polycaprolactone, and the cosolvent is at least one of glycerin, butanediol, pentanediol and hexanediol; The pore size of the filter membrane was 0.45 microns.
5. The method for preparing a pore-forming agent for lithium ion batteries according to claim 1, wherein in the step of preparing the W/O-type colostrum, the oil phase additive is at least one of simethicone, phenyl silicone oil and amino silicone oil, the emulsifier is at least two of span-40, span-60, span-65 and span-80, and the antifoaming agent is at least one of isopropanol, n-butanol, 1-octanol and ethanol.
6. The method for producing a pore-forming agent for lithium ion batteries according to claim 1, wherein in the step of producing W/O-type colostrum, the ionic strength adjuster is at least one of a sodium chloride solution, a potassium chloride solution and a calcium chloride solution.
7. The method for preparing a pore-forming agent for a lithium ion battery according to claim 1, wherein in the step of preparing the pore-forming agent for a lithium ion battery, the stirring speed is 200-500 r/min, and the stirring reaction is continued for 0.1-0.5 h after the dripping is finished; The specific operation of adjusting the pH value of the mixed system is that an acidity regulator is added into the mixed system until the pH value is 4-5, wherein the acidity regulator is at least one of hydrochloric acid-sodium citrate buffer solution, acetic acid-sodium acetate buffer solution, disodium hydrogen phosphate-sodium dihydrogen phosphate buffer solution and sodium citrate solution.
8. The method for preparing a pore-forming agent for lithium ion batteries according to claim 1, wherein in the step of preparing the pore-forming agent for lithium ion batteries, the washing, drying and pulverizing are performed by washing an emulsion with an ethanol-water solution and filtering to collect a solid product, drying the solid product in vacuum, and finally pulverizing the solid product and sieving the pulverized product with a 100-mesh sieve to obtain TM microcapsules.
9. A pore-forming agent for lithium ion batteries, characterized by being produced by the method for producing a pore-forming agent for lithium ion batteries according to any one of claims 1 to 8.
10. Use of a pore former for lithium ion batteries according to claim 9, wherein the use is in lithium ion batteries.

Description

Pore-forming agent for lithium ion battery and preparation method and application thereof Technical Field The invention relates to the technical field of lithium ion battery manufacturing, in particular to a pore-forming agent for a lithium ion battery and a preparation method thereof, and also relates to application of the pore-forming agent for the lithium ion battery. Background The lithium ion battery becomes an energy tie for connecting the digital world and the physical world due to the characteristics of high efficiency, portability and repeated charge and discharge. Its application has been extended to all corners of modern society. In the field of consumer electronics, it makes smart phones, notebook computers and tablet computers light and thin and long endurance possible. In the traffic field, the continuous reduction of the cost of the power battery directly promotes the large-scale use of the electric automobile. In the energy field, along with the increase of the renewable energy duty ratio, a large energy storage power station becomes a key facility for peak shaving of a power grid. More advanced applications have expanded to the sophisticated fields of aerospace, deep sea exploration and medical implant equipment. The working principle of the lithium ion battery is that lithium ions and electrons respectively pass through an internal circuit and an external circuit to shuttle back and forth at the same time. In the charge and discharge process, an external power supply or a load resistor can cause reversible oxidation and reduction reactions of the anode and the cathode. The negative and positive electrode materials are spatially separated but connected to the electrolyte ions by an external circuit. For lithium ion batteries, the transfer of electrons from the negative electrode to the positive electrode side is accompanied by extraction of lithium ions from the negative electrode material and intercalation into the positive electrode material to balance the charge. The internal structure of the lithium ion battery mainly comprises an anode, a cathode, electrolyte and a diaphragm, and the stable development of the lithium ion battery mainly depends on the four key systems, which jointly determine the quality of the lithium ion battery. Wherein the electrode is a very important part of a lithium ion battery. At present, an electrode material of a lithium ion battery mainly comprises an active substance, a conductive agent and a binder, is a mature industrial electrode, but has the problems of poor conductive performance, low dispersibility, swelling phenomenon, high cost and the like. Poor conductivity can lead to increased electrode resistance, rapid degradation of battery rate capability, and degradation of battery capacity over time. Swelling phenomenon damages the electrode structure and reduces the overall electrochemical performance of the battery. In order to solve these problems, researchers are looking for a material to improve the overall performance of the electrode, thereby improving the service life of the lithium ion battery. Disclosure of Invention In view of the above, the invention provides a pore-forming agent for a lithium ion battery and a preparation method thereof, and also relates to application of the pore-forming agent for the lithium ion battery, so as to solve the problems of poor electrical performance, swelling phenomenon and the like of the existing electrode. In a first aspect, the invention provides a preparation method of a pore-forming agent for a lithium ion battery, which comprises the following steps in parts by mass: Preparing a wall material, namely providing 2500-3500 parts of deionized water, 250-300 parts of cyanamide oligomer, 250-300 parts of urea compound and 800-1200 parts of lower aliphatic aldehyde, uniformly mixing the deionized water, the cyanamide oligomer, the urea compound and the lower aliphatic aldehyde, transferring the mixture into a first reaction kettle, regulating the pH value of the mixed solution in the first reaction kettle to 8.5-9, heating the first reaction kettle to 65-75 ℃ and maintaining the temperature for 0.5-1.5 h, continuously adding 10000-15000 parts of deionized water into the first reaction kettle after the reaction is finished, continuously stirring for 0.5-2 h, and standing for 0.5-1.5 h to obtain the wall material; Preparing a core material, namely providing 500-1000 parts of deionized water, 250-300 parts of polylactic acid and 10-30 parts of cosolvent, uniformly mixing the deionized water, the polylactic acid and the cosolvent, and then filtering the mixture to obtain a water phase core material; Providing 30-50 parts of oil phase additive, 1-10 parts of emulsifier and 1-5 parts of defoamer, adding the oil phase additive, the emulsifier and the defoamer into a second reaction kettle, and uniformly mixing to obtain an oil phase emulsifier; The pore-forming agent for the lithium ion battery is prepared by dropwise