Three-dimensional network adhesive for secondary battery and preparation method thereof, negative electrode slurry and negative electrode material

Abstract

The invention discloses a three-dimensional network adhesive for a secondary battery and a preparation method thereof, a negative electrode slurry and a negative electrode material. The adhesive is apolyacrylic acid-polyethylene glycol hydrogel polymeric adhesive having a three-dimensional network structure; the three-dimensional network structure is stable and has excellent mechanical properties, so that the irreversible slip does not occur between a polymer molecular chain and active particles when the three-dimensional network structure is applied to the battery, and the stress generated by the volume expansion of the active material can be effectively borne. In the preparation method of the three-dimensional network adhesive, the raw materials are easy to obtain, the cost is low, andthe repeatability is good, therefore, the preparation method of the three-dimensional network adhesive can be widely applied in actual production; by using the negative electrode slurry and the negative electrode material prepared through the adhesive, the problem of material powdering and electrode structure collapse due to volume expansion and contraction of the active material in the battery electrode during charging and discharging processes is solved; therefore, the capacity attenuation of the battery is relieved, and the cycle stability of the battery is improved.

Description

【Technical field】 [0001] The invention belongs to the technical field of secondary batteries, and in particular relates to a three-dimensional network adhesive for secondary batteries, a preparation method, negative electrode slurry and negative electrode materials. 【Background technique】 [0002] Secondary batteries are not only widely used in 3C electronic products such as mobile phones and notebooks, but also in emerging consumer fields such as new energy electric vehicles and drones, as well as land (individual combat systems, communication command systems), sea (submarines, underwater robots) Air (satellites, spacecraft) and other military field equipment / facilities provide important power sources. The rapid development of these high-tech, precision and cutting-edge technical fields urgently requires the development of secondary batteries with high specific energy, long life, and low cost. [0003] As the core component of the battery system, electrode materials play a...

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Problems solved by technology

[0004] (1) The negative electrode material is deintercalating ions (Li + 、Na + 、K + ) will produce a huge volume change (>300%), which will easily cause the active component particles to break, and then the particles will lose contact with the conductive additive, and the coating will be separated from the current collector, eventually leading to the destruction and collapse of the electrode structure;

[0005] (2) The solid electrolyte membrane (SEI) between the active component particles and the electrolyte is unstable

For silicon anodes prepared with such binders, multiple cycles will cause irreversible slippage between the polymer molecular chains of the linear structure and the active particles, which will cause the loss of electrical connectivity between the active material and the electrode matrix. The pole piece is destroyed, which leads to increased polarization and capacity attenuation

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