Industry News

Four common reasons for lithium battery accidents

2022-02-21
We first analyze why lithium batteries explode or burn electrically. Combustion or explosion usually occurs because heat is accumulated and cannot be diffused. It accumulates to the point of ignition, or the heat accumulates to a certain extent in a certain space.
1. Internal short circuit (mostly soft-packed macromonomers): Structural or process defects lead to the insertion of the tabs, too little excess diaphragm wrapping, burrs, and diaphragm discounts, etc. The insertion of the tabs often occurs in the structure of thick batteries and internal parallel connection, and the insulation of the tabs is not in place. Adding a protection board to the subsequent finished product or using a process may easily lead to an internal acute short circuit, resulting in burning or explosion (internal short circuit: this is a personal problem. I have a deep understanding. At that time, more than 2K batteries were scrapped, which was actually a design defect - the essence of the abnormality is: internal acute short circuit), but now this situation is almost rare, unless external factors.

2. External short circuit: The explosion after combustion caused by the external short circuit of the battery below 1AH is rare. It is usually caused by bulging or simply burning the tab. I have personally analyzed the combustion caused by the external short circuit of the power battery or large-capacity mobile phone battery. . This involves improper use by customers - the insulation of the tabs is not considered when installing the metal outer box, and abnormal smoke and combustion of the battery occur at the installation site; the power battery is also often insufficient in structural fixing measures (ill-considered), and the battery pack is used during the user's use. Shaking will cause damage to the external insulating protective film of the battery or damage to the connecting wire skin, which will eventually lead to short-circuit burning.

3. Overcharge explosion: This is the most dangerous, and the one that enterprises are most afraid of, but it still occurs occasionally. From what we know, there are two points: a. The user does not use the matching charger as required, thereby destroying the protection circuit and the user often charges for an unlimited time, which is difficult without frying; b. The battery is assembled Unreasonable and the protection plate fails, in this case, it will also explode in a mess... The same is true for single-cell batteries.

4. The material of the battery itself is not enough. If the material is not good enough, it may overheat at the rated voltage and current, resulting in an accident.