Preparation method for aqueous binder used for lithium ion battery

A water-based adhesive, lithium-ion battery technology, applied in the direction of acid copolymer adhesive, adhesive type, amide/imide polymer adhesive, etc., can solve the problem of reducing battery yield and compaction density Low cost, high price and other problems, to achieve the effect of good cycle performance and rate performance, low production cost and high compaction density

Inactive Publication Date: 2012-10-24
张倩
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, many lithium-ion battery factories still use traditional oily adhesives, namely polyvinylidene fluoride (PVDF) N-methylpyrrolidone solution, which pollutes the environment and is harmful to the health of operators. , the price is expensive, and it takes a long time to use the adhesive to make battery pole pieces, the baking temperature is high, and the energy consumption is large
Although some battery factories use CMC / SBR water-based adhesives in the production of negative electrodes to avoid environmental pollution and health hazards to production operators, this adhesive is not suitable for the production of positive electrodes for lithium-ion batteries.
At present, Chinese invention patent specifications CN01108511.8 and CN01108524.X disclose a relatively ideal lithium-ion battery adhesive LA132 water-based adhesive, which can be used for the production of lithium-ion battery positive and negative plates, and use it to make The performance of the lithium-ion battery is good, but when the binder is used in the production of the positive electrode sheet of the lithium battery, the compaction density is low, the electrode sheet is brittle after drying, and is easy to break, thus reducing the yield of battery production
Later, the Chinese invention patent specification CN200810300615.0 disclosed a kind of using polyvinyl alcohol or its acetal derivatives as the main polymer, and grafting monomers of different polarities in water to synthesize an aqueous polymer emulsion. The positive electrode sheet of the lithium battery produced has high compaction density and good flexibility, but the performance of the lithium-ion battery produced by using this binder is still not as good as that of the traditional oily binder, and needs to be improved

Method used

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  • Preparation method for aqueous binder used for lithium ion battery
  • Preparation method for aqueous binder used for lithium ion battery
  • Preparation method for aqueous binder used for lithium ion battery

Examples

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preparation example Construction

[0022] The invention provides a kind of preparation method of lithium-ion battery aqueous adhesive, comprises the steps:

[0023] (1) Weigh the raw materials according to the weight ratio of unsaturated hydrophilic monomer and unsaturated lipophilic monomer to 0.81~8:1, and then weigh the proportion of unsaturated hydrophilic monomer and unsaturated lipophilic monomer 0.3 to 4% of the total weight of additives;

[0024](2) Dissolve the above-mentioned weighed unsaturated hydrophilic monomer in distilled water to obtain an aqueous solution of unsaturated hydrophilic monomer, mix the aqueous solution of unsaturated hydrophilic monomer with unsaturated lipophilic monomer and additives Stir and mix evenly, the stirring speed is 20-360 rpm, the stirring time is 0.1-20 hours, and the weight ratio of unsaturated hydrophilic monomer to distilled water is 0.05-9:1;

[0025] (3) Adjust the pH value to 5-13 with an alkaline solution, and feed high-purity N 2 Exhaust oxygen for 0.5-3 ho...

Embodiment 1

[0040] In this embodiment, hydrophilic monomers acrylic acid (AA), acrylamide (AM) and lipophilic monomer vinyl acetate (VAc) are copolymerized in aqueous solution to generate a water-based adhesive for lithium ion batteries. Its comonomer composition is AA:AM:VAc=4:6:5 (mass ratio), the solid content of the copolymer is about 15%, and its appearance is emulsion-like.

[0041] The preparation method of the water-based adhesive for the above-mentioned lithium ion battery is: 6 parts of acrylic acid and 14 parts of acrylamide are dissolved in 70 parts and 90 parts of distilled water respectively, with 10 parts of vinyl acetate and 0.4 part of OP-10 emulsifier, in Stir and mix evenly in the reaction kettle, the stirring speed is 50 rpm, and the stirring time is 0.5 hours. Use 200g / L sodium hydroxide solution to adjust PH=9, feed nitrogen to drive oxygen for 2 hours, and the nitrogen flow rate is 30mL / min. Heating to 60°C and keeping the temperature constant for 1 hour, then addin...

Embodiment 2

[0044] The preparation method and operating conditions of the adhesive in this embodiment are basically the same as in Example 1. 8 parts of methacrylic acid and 14 parts of methacrylamide are dissolved in 70 parts and 90 parts of distilled water respectively, and mixed with 8 parts of styrene and 0.5 part of 2-octylphenol polyoxyethylene ether additive, stir and mix evenly in the reaction kettle, the stirring speed is 50 rpm, the stirring time is 3 hours, adjust the pH to 9 with 25% ammonia water, and pass in nitrogen Oxygen was driven for 2 hours, the nitrogen flow rate was 30mL / min, heated to 60°C and kept at a constant temperature for 1 hour, then 0.8 parts of sodium persulfate was added, and after 8 hours of reaction, the aqueous adhesive for lithium-ion batteries could be prepared. The solid content of the copolymer is about 15%, and the appearance of the product is emulsion.

[0045]Lithium-ion battery water-based binder performance detection is the same as in Example 1...

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Abstract

The invention provides a preparation method for an aqueous binder used for a lithium ion battery. The method comprises the following steps: weighing unsaturated hydrophilic monomers, unsaturated lipophilic monomers and auxiliary agents; dissolving the weighed unsaturated hydrophilic monomers in distilled water and uniform mixing the dissolved unsaturated hydrophilic monomers with the weighed unsaturated lipophilic monomers and auxiliary agents under stirring; adjusting the pH value of an obtained mixture to be 5 to 13, blowing in high purity nitrogen to remove oxygen and adjusting temperature to a constant temperature; adding an initiator for initiation of polymerization; and extracting residual monomers under vacuum so as to obtain the aqueous binder for a lithium ion battery. The aqueous binder for a lithium ion battery provided in the invention has the advantages of environment friendliness, low production cost and good bonding performance; an electrode slice prepared from the aqueous binder for a lithium ion battery has good flexibility and high compacted density and enables performance of positive and negative electrode materials of a lithium ion battery to be fully played; and a prepared lithium ion battery has good cycle performance and rate capability.

Description

technical field [0001] The invention relates to a preparation method of a water-based adhesive, in particular to a preparation method of a lithium-ion battery water-based adhesive. Background technique [0002] After decades of development, lithium-ion secondary batteries have been widely used in daily electronic products, aerospace, power stations, electric vehicles and other fields. Especially in recent years, countries around the world have attached great importance to new energy vehicles. Lithium-ion secondary batteries can be used as power sources for new energy vehicles, and their market prospects are bound to become wider and wider. [0003] Lithium-ion battery binder is one of the essential raw materials in the manufacturing process of lithium-ion batteries. Its function is to adhere the positive and negative electrode materials and conductive agents to the current collector. At present, many lithium-ion battery factories still use traditional oily adhesives, namely...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09J133/26C09J133/02C09J133/24C08F220/56C08F220/06C08F218/08C08F212/08C08F220/14C08F220/54C08F220/48C08F220/18H01M4/62
CPCY02E60/12Y02E60/10
Inventor 张倩张思方熊明强
Owner 张倩
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