How do you think about the safety performance of lithium battery packs?

What do we think about the safety of lithium battery packs? Battery overheating: Battery overheating will constitute thermal runaway, which is most likely to occur during battery charging and discharging. Because the lithium battery itself has a certain internal resistance, a certain amount of heat will be generated when the power is purely output, so their temperature becomes very high. When the temperature exceeds the normal working temperature, the plan will damage the battery life and safety. Influence of external force: Under the use of external force, lithium battery cells and battery packs are deformed, and the relative displacement of their different parts causes the battery gap to be torn and internal short circuit, flammable electrolyte leaks to the end, and causes a fire. Under the influence of external force, the puncture damage is the most serious. It can be directly inserted into the battery body to form a direct short circuit between the positive and negative electrodes. Improper use of electricity: When an external short circuit occurs, the heat generated by the battery cannot be dissipated well, the temperature of the battery will also rise, and the high temperature will trigger the thermal control. Overdischarge is one of the least harmful behaviors in the improper use of lithium battery pack method, but the addition of lithium dendrites formed by overdischarge will reduce the safety of the battery and increase the probability of heat loss. The use of lithium battery packs during charging is the most destructive misconduct. The growth of lithium dendrites on the anode surface is due to the excessive intercalation of lithium. Secondly, the excessive de-embedding of lithium leads to the decomposition of the cathode structure, which is due to the release of heat and oxygen (oxygen release of the NCA cathode). The release of oxygen accelerates the differentiation of electrolytes, and many gases appear. Due to the increased internal pressure, the exhaust valve opens and the battery is initially exhausted. When the active material in the battery contacts the air, it will react violently, releasing a lot of heat, and then causing the lithium battery to burn. Thermal runaway: The external temperature is high. The temperature control system may not work, causing the battery to overheat, forming a short circuit of the lithium battery, and causing thermal runaway. In fact, the collision and damage of the lithium battery, the structure and function of the battery, or the failure of other heat treatment systems, the air conditioning system may cause the heat to run out of control. Lithium battery packs are so dangerous, but we have many lithium battery pack products in one day, and dangerous operations are very few. This is because the manufacturer has taken adequate safety protection measures for the lithium battery pack during the processing planning process to ensure the safety of the lithium battery pack and the safety of customers. The self-safety method of lithium battery packs heat shut off barriers: when the battery is caused by acupuncture or pinching to form a large current through the battery, such as the battery temperature rises, the internal porous gap of the battery will loosely soften, because the battery core is tight, the kneaded gap will mutually Adhesion is simple because of its porous structure and a completely enclosed structure, and it stops continuous ion transport and chemical reactions. The current goal is to regulate the cut. Qualified battery safety features often prevent the temperature from rising further in this link, making the battery no longer dangerous. Add a protective film to the battery, so that the battery is punctured, and can be actively powered on to prevent explosion. Positive temperature coefficient resistance: When the battery is overcharged or externally short-circuited, a large amount of current will cause the temperature of the battery's positive temperature coefficient resistance, which will then cause the resistance to heat up and increase the value of the resistance, thereby reducing the current flowing through the battery and ensuring the safety of the battery . It is equivalent to adding a resistance protector, overcharge or short circuit→high current→heating→resistance improvement→decreasing current→safety guarantee. Safety valve: After the battery is overcharged, the electrolyte is heated to vaporize and the electrolyte separates gas, there may be a sudden increase in air pressure in the battery, which may cause the battery to burst. The explosion-proof valve or explosion-proof membrane is planned for this purpose. They will separate in time, release the internal pressure of the battery, and then ensure the personal safety of industrial users. The safety valve knows that the battery is charged with anger, and the first exploded battery is pessimistic to ensure safety. Lithium battery UPS power protection tips: Check for signs of battery corrosion or other defects. Check the obstacles of UPS and lithium battery (or other energy storage equipment) equipment, and properly cool the surrounding area. Make sure that there are no faults or warnings on the UPS panel, such as overload or near-discharge of the battery. When we usually use UPS lithium batteries to supply power, we see dust on the UPS host, and we should also develop a habit of cleaning so that dust will not accumulate more and more. Long-term maintenance and cleaning of the UPS host will provide us with better, More stable and reliable power supply. More general information about lithium battery UPS protection is best left to those who know the rules of UPS enforcement. In addition, safety is also crucial: repairing the UPS system is inherently risky, so it is better to hire a professional, rather than risking your life (and then shutting down) to repair the system yourself. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Common use scenarios of lithium battery UPS