Cause the cause analysis of lithium-ion batteries

Source: 2020 - 03 - 13:15 hits: 26 times the cause batteries overheating: lithium-ion batteries battery overheat would amount to a thermal runaway, the overheating in the battery charge and discharge process is the most likely to occur. Because lithium-ion battery itself has certain internal resistance, in the output of the power electric power supply at the same time will happen in a certain quantity of heat, so their temperature becomes high, when the temperature exceeds normal working temperature range will damage the battery life and safety. The influence of the external force: in under the action of external force, and lithium battery monomer battery pack is deformed, and the relative displacement occurred in different regions of the battery, in battery diaphragm tear and causing short circuit, finally flammable electrolyte leakage cause fire. Under the influence of the external force, piercing damage is most serious, it can be directly inserted into the battery body, form the positive and negative electrode short circuit directly. Improper power: when the external short circuit occurs, the heat generated by the battery not well dissipation, battery temperature will also rise, high temperature can trigger hot control. Excessive discharge of the lithium battery encapsulation using one of the least behavior, but the excessive discharge of the lithium dendrite growth will reduce the safety of the battery, increase the risk of thermal runaway. Using lithium battery in the process of charging is the most destructive behavior. Lithium dendrite growth in the anode surface, this is due to the excessive embedding of lithium. Second, the excessive to the embedding of lithium can lead to collapse due to the release of heat and oxygen cathode structure ( The NCA cathode oxygen release) 。 The release of oxygen accelerated the electrolyte composition, generated a lot of gas. Due to internal pressure increases, the exhaust valve opens, cells begin to exhaust. Active substances in the battery after exposed to air, can produce a strong reaction, release a lot of heat, and then lead to lithium battery to calm down and catch fire. Thermal runaway: when the external environment temperature or temperature control system can not work, battery quantity of heat is too high, lead to lithium battery short circuit, leading to thermal runaway. In practice, collision, damage lithium-ion batteries, battery thermal management system such as internal structure, function, air conditioning system failure may cause the heat out of control. Lithium-ion battery pack is very dangerous, but in our life there are a lot of lithium battery products, and the actual is rarely dangerous work. This is because the consumer manufacturer in lithium battery consumption stopped enough safety measures in the design process, to ensure the safety of lithium-ion battery pack, to ensure the safety of the clients