Analyze the safety performance of lithium-ion batteries

Lithium-ion battery safety analysis is well known, lithium-ion batteries are a good thing, but many factors affect the normal operation of lithium-ion batteries, such as working temperature, environmental humidity, uneven cooling, overcharge and discharge, BMS, vibration, system groups, production Process, etc., may cause the battery to fail. Failure does not necessarily have to catch fire, but the battery performance is no longer suitable for running on the system and must be replaced or deleted, otherwise it will affect the operation of the system. So many factors are mixed together, like a mess, making people feel that it is not small for a lithium-ion battery system to run without failure, but it lacks data support. Lithium-ion batteries The following are typical products of lithium-ion batteries. According to the probability calculation results, discuss the impact of product qualification rate on the system failure rate: (1) mobile phone battery; (2) electric vehicle battery pack: Tesla battery pack, 7104 battery packs (3) large energy storage series, 250kw× 2h, 500kw×2h. 1 Mobile phone battery First of all, single-cell battery, due to its small capacity (about 1000mAh) and mature technology, the qualification rate is among the top three in the list of domestic and foreign manufacturers, that is, the failure rate can be controlled within 100,000. For example, there are 8 million people in Nanjing, and everyone has a mobile phone. In the whole of Nanjing, the number of cell phone battery failures is about 100, possibly even more. However, the calculation results are consistent with the daily feeling that a single lithium-ion battery has higher safety. 2 Different companies of electric vehicles have different technical routes, which are mainly reflected in the following aspects: (1) different battery types, ternary and lithium iron; (2) different capacities and different sizes. It can use a small battery of about 3AH, such as Tesla, or a large battery of about 26AH, such as BYD; (3) The shape is also different, with a cylindrical 18650 or 20700, with a large cooling area, which is convenient for thermal management. Modular fixed installation of square battery pack. 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: What causes the scrap of lithium-ion battery cars