Method for preparing AGM (Absorptive Glass Met) separator with high specific surface area

Abstract

The invention discloses a method for preparing an AGM separator with high specific surface area. The method comprises the following steps: preparing glass fiber slurry from water and glass fibers, adding water for diluting, and regulating the pH value; performing negative pressure suction filtration and dehydration so as to obtain a primary molded wet separator; and applying nanosized silica aqueous dispersion to the surface of the wet separator, performing negative pressure suction filtration and dehydration so as to obtain a secondary molded wet separator, and drying, thereby obtaining the AGM separator with high specific surface area. The AGM separator with high specific surface area disclosed by the invention can achieve the effects of improving the stability and uniformity of a colloidal network structure and improving the layering phenomenon of electrolyte; meanwhile, the problem that the AGM separator is low in wet elasticity and low in assembly pressure retaining capacity is effectively solved, the pore size of the separator can be greatly reduced, the performance of preventing short circuit caused by dendrite puncture can be further improved, capacity degradation of a storage battery is retarded, and the cycle service life of the storage battery is prolonged.

Description

technical field [0001] The invention belongs to the field of storage batteries, and more specifically relates to a method for preparing an AGM separator with a high specific surface area, and the separator is suitable for lead-acid batteries. Background technique [0002] The battery separator is a porous insulating material, which is placed between the positive and negative plates of the battery to separate the positive and negative plates and play the role of insulation to avoid short circuit of the battery. At the same time, the ions that participate in the chemical reaction are allowed to pass through during the charging and discharging process of the battery. For the sealed maintenance-free battery, it is also necessary to ensure that the oxygen precipitated from the positive electrode reaches the negative electrode through the separator to complete the hydrogen-oxygen recombination reaction. Therefore, as an important part of the battery, the separator plays a decisive...

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Problems solved by technology

In the present invention, the particle size of nano silicon oxide is 1.5-10nm, and the specific surface area is 680-1100㎡ / g. The AGM separator with high specific surface area is prepared. The glass fiber separator material has a more complex zigzag channel structure, which improves the separator The specific surface area of ​​the plate; the tortuosity factor of the pore structure of the separator is increased, and the diffusion flux of the acidic medium is greatly reduced, thus improving the acid-carrying capacity of the separator and greatly reducing the stratification of the electrolyte inside the battery; A rich porous network structure is formed in the separator, coupled with the porosity of the separator itself, the wet elasticity of the separator is enhanced, which effectively solves the problems of low wet elasticity and poor assembly pressure holding capacity of the AGM separator; at the same time, complex twists and turns The pore structure can eliminate the phenomenon that the positive electrode active material forms dendrites and punctures the separator to cause micro-short circuit

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