Factors Affecting Battery Test
erevnt short circuit caused by contact between the two poles. The material is PP film, PE film, two-layer PE/PP composite film or PP/PE/PP three-layer composite film. These materials are not electrically conductive, but have the ability to pass electrolyte ions. The thickness of the diaphragm, the closed cell temperature, the film rupture temperature, the aperture ratio, the direction of the stretch, the wettability, and the absence of coating all affect the safety of the battery to a large extent.
- Cylindrical batteries are easily pierced at different speeds of the needle, causing the battery to shoNrt-circuit and explode.
Because the positive and negative electrodes of the cylindrical battery and the diaphragm use a high pressure winding method. This will result in a small positive and negative gap. When the battery encounters a needle stick, the diaphragm cannot extend. The steel pin acts as a conductor to connect the positive and negative electrodes, thereby causing a short circuit.
- Soft pack batteries are greatly affected by the needling speed and are easier to pass through.
Because the soft pack battery is a layered structure, the gap between the positive and negative electrodes is large. When the battery encounters a needling, the diaphragm can extend or even wrap the steel needle. This will make the positive and negative poles not turn on, and will not cause the battery to short circuit or explode.
Therefore, in order to improve the needle safety performance of the battery when manufacturing the battery, it can be operated in the following manner:
- Appropriately increase the gap between the positive and negative electrodes;
- Try to increase the ductility of the diaphragm;