How to judge the mechanical performance of lithium ion batteries?

Mechanical properties

(1) Extrusion: Place the single cell in the middle of two extrusion planes and gradually increase the pressure to 13 kN. The extrusion direction of the cylindrical cell is perpendicular to the longitudinal axis of the cylindrical axis. The square cell extrudes the wide and narrow sides of the cell. Each battery can only be squeezed once. The test results should meet the requirements of 4.1.2.1. Put a 15 cm steel rod on the battery to extrude the wide and narrow sides of the battery pack until 85% of the original size of the battery pack, and keep it for 5 minutes. Each battery pack only receives one extrusion.

(2) Acupuncture: Put the single battery in a steel fixture, and run through the battery plate perpendicular to the direction of 3mm~8mm steel nail (the needle stays in the battery) for 90 minutes, or stop the test when the surface temperature of the battery is stable (the temperature difference within 45 minutes is less than 2 C).

(3) Heavy impact: Place the single battery on a steel plane, with a 15.8mm diameter steel bar in the center of the battery, the longitudinal axis of the steel bar parallel to the plane, let the weight of 9.1kg fall freely from 610mm height to the steel bar in the center of the battery; when the single battery is cylindrical, the impact direction is perpendicular to the vertical axis of the cylindrical surface; when the single battery is square, the wide surface of the battery should be impacted. And on the narrow side, each battery can only accept one impact.

(4) mechanical impact; fix the battery or battery group on the test equipment by rigid fixing method (this method can support all fixed surfaces of the battery or battery group). Each of the three perpendicular directions bears an equivalent impact. At least one direction should be perpendicular to the wide surface of the battery or battery. Each shock should be carried out in the following way: within the initial 3ms, the minimum average acceleration is 735m/s2, and the peak acceleration should be between 1225m/s2 and 1715m/s2.

(5) Vibration: Vibration test is carried out by installing batteries or batteries directly or fixtures on the vibration table. The test conditions are frequency 10 Hz-55 Hz, acceleration 29.4 m/s 2, frequency sweep cycles 10 times in each direction of XYZ and frequency sweep rate 1 oct/min.

(6) Free drop: the single battery or battery group will be freely dropped from the height (lowest height) of 600 mm to the 20 mm thick hardwood board on the cement floor, once from the three directions of XYZ. After the free fall.

The page contains the contents of the machine translation.