Battery deformation.lithium ion battery 18650 price

　　1. Failure cause:

　　Battery deformation is not an emergency, often there is a process. The battery enters a high -voltage charging area about 80%of the charging to the capacity. At this time, the oxygen is used first in the positive electrode, and the oxygen can reach the negative electrode through the holes in the partition. A reaction of oxygen resurrection on the negative plate:

　　2pb+O2 = 2pbo+calories

　　PBO+H2SO4 = PBSO4+H2O+calories

　　The heat generates heat during the reaction. When the charging capacity reaches 90%, the oxygen rate increases, and the negative electrode starts to generate hydrogen. The increase in a large amount of gas is that the internal pressure of the battery exceeds the opening valve pressure, the safety valve is opened, and the gas is lifted, and the water is finally manifested.

　　2H2O = H2é+O2é

　　As the number of battery cycles increases, the water gradually decreases, and the result is the following situation:

　　(1) The "channel" of oxygen becomes smooth, and the oxygen generated by the positive electrode can easily reach the negative electrode through the "channel".

　　(2) The heat capacity is reduced, and the most hot capacity in the battery is water. After the water loss, the battery heat capacity greatly reduced, and the heat generated increased the temperature of the battery quickly.

　　(3) Due to the contraction of the super glass fiber partition in the battery after the water loss, the adhesion of the positive and negative plate becomes worse, the internal resistance becomes larger, and the heat of the charging and discharge process increases. After the above process, the heat generated inside the battery can only be dissipated by the battery tank. If the heat dissipation is less than the heat, the temperature increases, which reduces the battery inhalation of overpower, increases the amount of aspiration, and a large amount of oxygen in the positive pole passes through the "channel", which reacts on the negative surface and emits a large amount of heat to quickly increase the temperature. The formation of a vicious cycle leads to "heat out of control" and deforms.

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