Introduction to the safety features of lithium-ion batteries

Safety characteristics of lithium-ion batteries Lithium-ion batteries have been widely used in people's daily life, and their safety performance should be the primary evaluation index for lithium-ion batteries. Regarding the evaluation index of the safety performance of lithium-ion batteries, there are very strict standards in the world. Qualified lithium-ion batteries should meet the following conditions in terms of safety performance. (1) Short circuit: no fire, no explosion (2) Overcharge: no fire, no explosion (3) Hot box test: no fire, no explosion (constant temperature of 150°C for 10 min) (4) Needle stick: no explosion (3 mm) Ф penetrates cells) (5) Flat plate impact: no fire, no explosion (10kg weight falls on the battery from a height of 1 meter) (6) Incineration: no explosion (gas flame barbecue battery) How to realize the safety features of lithium ion batteries In order to ensure the safe use of lithium-ion batteries, experts have carried out a very strict and thorough battery safety design to meet the battery safety assessment indicators. (1) Diaphragm automatic cut-off protection at 135℃: The international advanced celgard2300pe-pp-pe three-layer composite film is adopted. When the battery temperature reaches 120°C, the PE film pores on both sides of the composite film are closed, the internal resistance of the battery increases, and the internal temperature of the battery decreases. When the battery temperature reaches 135°C, the PP film hole is closed, the internal circuit is disconnected, and the battery no longer heats up to ensure battery safety. (2) To the electro-hydraulic system: Under the condition of adding additives, the battery is charged, and the battery voltage is greater than 4.2v, the electro-hydraulic system will polymerize with other substances in the electro-hydraulic system, and the internal resistance of the battery will be added, resulting in a large area of u200bu200binternal open circuit of the battery. And the battery will no longer heat up. (3) Battery cover composite structure: The battery cover adopts a cut-out explosion-proof structure. When the battery heats up, part of the gas that occurs during the internal activation of the battery expands, and the internal pressure of the battery increases. The pressure reaches a certain degree of gap rupture and exhaust. (4) Various environmental abuse tests: Conduct various abuse tests, such as external short-circuit, overcharge, acupuncture, plate impact, and incineration, etc., to investigate the safety performance of the battery. At the same time, mechanical performance tests such as temperature shock, vibration, drop, and impact were carried out on the battery, and the performance of the battery in the actual use environment was investigated. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.