Aqueous inorganic glue and preparation method and application thereof

Abstract

The invention belongs to the field of electrode paste and discloses aqueous inorganic glue and a preparation method and application thereof. The aqueous inorganic glue is a uniform and stable solid-liquid two-phase dispersion system which is between a solution and a precipitate, the aqueous inorganic glue comprises an insoluble or a sparingly-soluble solid phase dispersion substance and a liquid phase dispersion agent, and the aqueous inorganic glue can be prepared by a liquid phase growth method or a solid phase breaking method, and can be used in the aspects of paste-coated electrodes, non-paste-coated electrode, coated electrode active materials, coated hydrogen storage alloys and the like. Metal compounds (mainly metal oxides or hydroxides) are used for preparation of aqueous inorganic glue additives to replace traditional metal compound powder additives, problems such as addition uniformity and additive utilization rate and the like can be solved, traditional organic polymer colloid can be replaced, or the dosage of the traditional organic polymer colloid is greatly reduced, negative impacts of the traditional organic polymer colloid on the battery performance can be eliminated or weakened.

Description

technical field [0001] The invention belongs to the field of electrode slurry, in particular to a water-based inorganic glue and its preparation method and application. Background technique [0002] Generally speaking, most batteries of water-based systems, especially paste-type electrodes (the active material is coated on the conductive substrate, and the mixture of the active material and other components presents a wet state when coating, such as gel, Fluid wet slurry, semi-wet solid mixture, etc.), in order to increase the uniformity of active substance distribution, the stability of the mixture, and the uniformity of coating, etc., some thickeners, suspending agents, emulsifiers, Flocculants, colloidal protective agents, fluid modifiers, binders, etc., for the convenience of description, the substances that realize these functions will be collectively referred to as water-based organic polymer colloids in this article, and the common ones are celluloses such as CMC, HPM...

AI Technical Summary

Problems solved by technology

The use of such substances generally has the following problems: if the amount is too small, the mixing system will not be able to resist gravity sieving and will be stratified; The bondage of hydrophilicity to the aqueous electrolyte causes the battery to deteriorate such as impedance, magnification, and platform. The complexity and stability of such macromolecular substances often lead to performance degradation or consistency changes in battery voltage, charge, and life. Difference

Such additives are often difficult to dissolve in water or in the electrolyte. In addition to adding in the form of a solid solution or a co-solution when preparing the active material, it can be relatively uniform, such as the active material, additives, and various additives. and other mechanical mixing methods, because these additives are in the form of solid powder or small particles, it is difficult to disperse the additives uniformly in the active substance

In order to achieve uniform addition, very fine-grained additives are often used, but it also brings difficulties in agglomeration and redispersion, and the production cost of very fine-grained (such as nano-scale) substances is high.

On the other hand, the utilization rate of additives with coarse particle size is often low. In order to ensure sufficient effect, the amount of additives can only be increased. For more expensive additives, the pressure on the cost of additives is exacerbated. On the other hand, such additives are often They are all substances with poor conductivity. Larger particle size and more added amount will bring negative effects on the increase of electrode impedance.

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