Comparison of Gel battery and AGM battery - 3
○ Battery structure and process ○
AGM sealed lead-acid battery uses pure sulfuric acid aqueous solution as electrolyte, and its density is 1.29-1.3lg/cm3. Except for a part of the electrolyte absorbed inside the plate, most of it exists in the GLASS FIBER MEMBRANE. In order to provide a channel for the oxygen precipitated from the positive electrode to the negative electrode, it is necessary to keep 10% of the pores of the separator that is not occupied by the electrolyte, that is, a lean liquid design. In order to make the electrode plate fully contact the electrolyte, the electrode group adopts the method of tight assembly.
In addition, in order to ensure sufficient battery life, the plate should be designed to be thicker, and the positive grid alloy uses Pb'-q2w-Srr--A1 quaternary alloy.
The electrolyte of colloidal-sealed lead-acid battery is composed of silica sol and sulfuric acid. The concentration of sulfuric acid solution is lower than that of AGM batteries, usually 1.26-1.28g/cm3. The amount of electrolyte is 20% more than that of AGM batteries, which is comparable to that of flooded batteries. This electrolyte exists in a colloidal state and is filled in the separator and between the positive and negative electrodes. The sulfuric acid electrolyte is surrounded by the gel and will not flow out of the battery.
Since this battery adopts a flooded non-tight assembly structure, the positive electrode grid material can be made of low antimony alloy, or a tubular battery positive plate can be used. At the same time, in order to increase battery capacity without reducing battery life, the plates can be made thinner. The internal space of the battery slot can also be expanded.
○ Battery discharge capacity ○
The discharge capacity of the initial colloidal battery is only about 80% of the flooded battery. This is because the colloidal electrolyte with poor performance is directly poured into the unmodified flooded battery, the internal resistance of the battery is large, and the electrolyte due to the difficulty in ion migration.
Subsequent research work showed that the formulation of colloidal electrolyte was improved, the size of colloidal particles was controlled, hydrophilic polymer additives were added, and the concentration of the colloidal liquid was reduced to improve the permeability and the affinity of the electrode plate. Plate or AGM SEPARATOR replaces the rubber separator to improve the liquid absorption of the battery; cancel the precipitation tank of the battery, and appropriately increase the content of the active material in the area of the electrode plate, as a result, the discharge capacity of the colloidal sealed battery can reach or be close to that of the open lead battery Level.
AGM sealed lead-acid batteries have less electrolyte, thicker plates, and lower active material utilization than open-type batteries, so the discharge capacity of the battery is about 10% lower than that of open-type batteries. Compared to today's gel-sealed batteries, the discharge capacity is a bit smaller.
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