How to Analysis And Solutions To Common Problems Of Lithium Batteries

Due to the rapid development of science and technology, the scope and role of lithium batteries have long been taken for granted.   Accidents involving lithium cells and batteries have happened throughout our lives, and an endless stream of lithium has always plagued us.

Self-discharge cells are large because their voltage drops faster than other cells, and low voltages can be eliminated by controlling voltage during storage. When you charge the battery for a test, you can charge its cells by charging the current and then discharging it at a voltage lower than the charging current of the cell.

For short-term storage (12 hours) the measured voltage difference is small, for long-term storage the voltage differences are greater. Low voltages have quality problems and can be solved by storing the voltage measured after it has been charged during production.

If the detection accuracy is insufficient, the internal resistance of the display is too high because the contact group cannot be removed. The principle of alternating current bridge should be used to test internal resistance, but if the detection accuracy is insufficient.

If the detection accuracy is insufficient, the internal resistance of the display is too high because the contact group cannot be removed. The principle of alternating current bridge should be used to test internal resistance, but if the detection accuracy is insufficient.

Excessive charging decomposes the electrolyte, which increases internal pressure and expands the lithium battery. Generally, overcharging causes lithium batteries to expand and expand when charged and exceed 0.1 mm during charging. When the battery is plugged in, the thickness increases and increases until it exceeds 1 mm, and when charged, it expands to 1.5 mm and then 2 mm. This is generally caused by electrolytes that disintegrate due to excessive heating, increasing internal pressure and expanding the batteries.

This phenomenon is caused by normal battery reactions, and generally the normal increase is between 0.3 and 0.6 mm. The aluminium cover is more serious, but can cause damage to the battery by excessive heating.

If the shell is thicker and the inner material is reduced, the expansion phenomenon can be reduced by reducing the outer shell and thus the thickness of the outer layer.

The correct welding spot position should be welded with pinpoint precision on the underside with the marking "A." Spot welding is not permitted on either side of the larger side marker, and incorrect spot welding usually causes a short circuit in the inner membrane of a lithium-ion battery cell. Spot welding should not be lower than 3.7V, as the spot welding current can cause the inner membranes of cells to collapse and short circuits, causing the voltage to drop too quickly.

In addition, spot-welded nickel strips have poor weldability and can puncture themselves, while the internal high-temperature resistant strip does not function properly, resulting in an internal battery short-circuit. If a battery loses power due to spot welding, the charging current is too high and the lithium ions are too late to be inserted, or the protective circuit is out of control, lithium metal forms a gap large enough to penetrate the membrane and cause the positive and negative electrodes to short circuit - which rarely causes an explosion. Even if the detection cabinet is under control and the charging voltage is below 5V (which decomposes the electrolyte and causes a violent reaction in the batteries), if there are no detection cabinets in the control, or if the charging voltage is below 3.7V, although the charge-to-discharge ratio (the ratio of lithium to lithium-ion) is in the control, charging volts can be up to 0.5 V, which can directly cause short circuits of a positive or negative electrode (which causes explosions), can cause a rapid increase in the internal pressure in the batteries (which rises rapidly) or lead to an explosion of batteries (explodes).

Ultrasonic energy is transmitted to the battery core by ultrasonic welding of the plastic housing equipment. Ultrasonic energy is transmitted to the battery core by ultrasonic welding on plastic housings and devices and then passed through the electrodes to lithium-ion batteries.

Excessive current and spot welding cause a severe internal short circuit - which leads to explosion. Ultrasonic energy is so strong that the positive and negative electrodes are directly short-circuited and cause an explosion, but this is rare. The positive electrode connection is connected to the negative electrode by welding, which causes them to be short-circuited and explode directly. The discharge current (3C discharge) of a battery detaches and deposits the negative electrode foil on the separator, discharging lithium-ion batteries from the battery core into the surface of the plastic housing.

When a battery vibrates or falls violently, the inner poles of the battery are deflected and are directly short-circuited - i.e. shut down.