Lithium ion battery aqueous binding agent and preparation method thereof

Abstract

The invention discloses a lithium ion battery aqueous binding agent. The lithium ion battery aqueous binding agent comprises emulsion and latex particles, wherein the latex particles are dispersed inthe emulsion and are of three-layer structures, an inner core comprises a polymer with low glass-transition temperature, an intermediate transition layer comprises a polymer with a middle glass-transition temperature, a shell layer comprises a polymer with high glass temperature, and the three-layer structure gradually becomes hard from soft from inside to outside, the solid content of the emulsion accounts for 5-30%, and the mass ratio of the inner core polymer, the intermediate transition layer polymer and the shell layer polymer is (5-30):(20-60):(30-60). In the lithium ion battery aqueousbinding agent obtained by the invention, the binding agent takes water as a dispersion medium, and the problem of environmental protection of the binding agent for a lithium battery is solved; with the synthesis method of the inner core, the transition layer and the shell, the emulsion of the prepared binding agent is good in mechanical stability, and a demulsification phenomenon such as agglomeration during the dispersion process cannot be generated; and the binding agent is relatively low in surface tension, and the dispersing efficiency and the film formation performance are greatly improved.

Description

technical field [0001] The invention relates to the field of lithium-ion battery materials, and mainly relates to a lithium-ion battery water-based adhesive and a preparation method thereof. Background technique [0002] With the development of science and technology and the improvement of people's material and cultural living standards, people's requirements for movable secondary batteries are also getting higher and higher. Lithium-ion secondary batteries can meet people's requirements for mobile power in many ways. At present, lithium-ion batteries are widely used in mobile digital products, aircraft model toys, electric vehicles and automobiles. At the same time, because lithium-ion batteries are in line with the national policy of energy conservation, emission reduction and sustainable development, in the new energy planning, it is advocated to vigorously develop lithium-ion batteries in the next 10-15 years. At the same time, with the continuous growth of my country's...

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Problems solved by technology

[0004] At present, researchers at home and abroad have done a lot of research work on this, and CN01108511.8, CN01108524.X disclose a kind of adhesive, but in the process of actual use, the adhesive also has the following disadvantages: low-temperature baking is required , leading to low production efficiency, the prepared pole piece is brittle and poor in flexibility, which leads to easy breakage during the battery preparation process, and warpage during the production process, resulting in the formation of waste products in the battery and increasing the production cost of the battery; CN201410731027.8, CN200910300150.3 adopts low-polarity polymer as core, and high-polarity polymer is made shell and synthesizes the lithium ion water-based adhesive that softness has improved, but, because adopting existing polymer as reaction core, so selectivity and The designability is poor, and this product has not been able to improve the problems existing in the lithium-ion battery manufacturing process.