Controllable water-soluble battery adhesive and preparation method thereof

Abstract

The invention discloses an adjustable water-soluble battery adhesive, which is prepared from the following raw materials in parts by weight: 2 to 5 parts of aliphatic dianhydride, 0.1 to 1 part of aromatic diamine, 15 to 20 parts of solvent and 1.5 to 2.5 parts of catalyst. According to the present invention, the oxygen group substituted biphenyl diamine is adopted as the aromatic diamine, such that the soft and hard chain segment structure distribution of the polyimide adhesive can be regulated and controlled, the compatibility with the aliphatic dianhydride can be increased, the adhesive can form the compact membrane structure, and the interface impedance of the battery can be reduced; according to the present invention, by using the aliphatic dianhydride and the 1, 2, 3, 4-tetrahydro-1-naphthalenesuccinic acid dianhydride, the flexibility of the polyimide is improved, the good mechanical stability and the appropriate viscosity are provided, and when the polyimide is applied to the negative electrode of the battery, the cycle performance of the battery under the high current density charge-discharge condition is improved, and the influence of the rapid charge operation on the service life of the battery is reduced.

Description

technical field [0001] The invention relates to a controllable water-soluble battery binder, relates to C08G, and in particular relates to the field of polymer compounds obtained by reactions other than carbon-carbon unsaturated bonds. Background technique [0002] The battery binder is an important part of the battery. At present, the most common lithium battery on the market, the electrode sheet will change in volume during the charging and discharging process, and it is difficult to maintain the integrity of the electrode sheet, especially under high-density current. During the fast charging operation, the charging efficiency and discharging efficiency of the battery will be greatly reduced. As a new type of polymer material, polyimide has good thermal stability, non-flammability, and good mechanical stability. It is widely used in battery anode materials, but the water solubility of traditional polyimide materials is poor, which leads to a decrease in processability. The...

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Problems solved by technology

[0002] The battery binder is an important part of the battery. For the most common lithium battery on the market, the volume of the electrode sheet will change during charging and discharging, and it is difficult to maintain the integrity of the electrode sheet. Especially under high-density current, the battery will During fast charging operation, the charging performance and discharging performance of the battery will be greatly reduced. As a new type of polymer material, polyimide has good thermal stability, non-flammability, and good mechanical stability. It is widely used in battery anode materials, but the traditional polyimide materials have poor water solubility, which leads to a decrease in processability. Therefore, it is very important to develop a polyimide material with adjustable structure and water solubility.

[0003] Chinese invention patent CN202011474945.9 discloses a low thermal expansion coefficient thermoplastic polyimide resin and its preparation method. The flexible polyimide is obtained by copolymerizing flexible dianhydride and flexible diamine monomer, which improves the polyimide The overall heat resistance, but the mechanical stability performance is greatly reduced

Chinese invention patent CN201610852846.7 discloses a method for preparing a highly adhesive polyimide film. The polyimide film is formed by polymerizing rigid and flexible diamines and dianhydrides at the same time, while maintaining a certain mechanical strength. It also has certain plasticity, but the water solubility of the formed polyimide film is not good, and the processability between the battery electrode and the battery electrode is not good.

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