What are the failure situations of lead-acid batteries?

The failure modes of lead-acid batteries are due to differences in the types of plates, manufacturing conditions, and methods of use, which ultimately lead to different reasons for battery failure. In summary, the failure of lead-acid batteries has the following situations: 1. Corrosion and deformation of the positive plate. There are currently three types of alloys used in processing: traditional lead-antimony alloys with an antimony content of 4%-7% by mass; low antimony or ultra-low antimony alloys with an antimony content of 2% by mass or less than 1% by mass Fractions, containing tin, copper, cadmium, sulfur and other modified crystal agents; lead-calcium series, actually lead-calcium-tin-aluminum quaternary alloy, the content of calcium is 0.06%-0.10% by mass. The positive grids cast by the above alloys will be oxidized into lead sulfate and lead dioxide during the battery charging process, and finally lead to the loss of the use of supporting active materials and the battery failure; or the formation of lead dioxide corrosion layer makes lead Stress in the alloy causes the grid to grow and deform. When this deformation exceeds 4%, the entire electrode plate will be destroyed, and the active material will fall off due to poor contact with the grid, or short-circuit at the busbar. 2. The active material of the positive plate falls off and softens. In addition to the growth of the grid causing the active material to fall off, as the charge and discharge are repeated, the bond between the lead dioxide particles also relaxes, softens, and falls off the grid. A series of factors, such as the manufacture of the grid, the tightness of the assembly, and the charging and discharging conditions, all have an impact on the softening and shedding of the active material of the positive plate. 3. Irreversible sulfation. When a battery is over-discharged and stored in a discharged state for a long time, its negative electrode will form a coarse lead sulfate crystal that is difficult to accept charging. This phenomenon is called irreversible sulfation. Slight irreversible sulfation can still be recovered by some methods; in severe cases, the electrode will fail and cannot be charged. 4. Premature loss of capacity. When low antimony or lead-calcium is the grid alloy, the capacity suddenly drops in the initial stage of battery use (about 20 cycles), causing the battery to fail. 5. Severe accumulation of antimony on active materials. The antimony on the positive grid transfers to the surface of the active material on the negative plate with the circulation part. Since the overpotential of H+ reduction on antimony is about 200mV lower than that on lead, the charging voltage decreases when antimony accumulates, and most of the current Both are used for water decomposition, and the battery cannot be charged normally and therefore becomes invalid. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete it. Previous article: What are the precautions for carrying lithium batteries?