Summary.
In recent years, with the gradual shift towards the automotive industryElectric vehicles and autonomous drivingThe quality of parts and components has improved, and the reliability requirements for on-board batteries have also been continuously improved. ForSafer production of batteriesAvoid the risk of fire due to battery defectsDefect detection on the production line is particularly important.
Hioki products can respond to the rapid growth in demand for batteries by performing detailed battery inspections to detect minor defects while maintaining production efficiency, thereby improving battery quality and production efficiency.
Solutions for this issue:
1.Check the insulation resistance of lithium batteries.
2.Safety testing of lithium batteries: DC withstand voltage test.
3.Welding quality inspection in the lithium battery production process.
Insulation resistance check
The battery must be insulated between the positive and negative poles and between the electrodes and the outside (housing). If insulation is not maintained (insufficient insulation resistance), it can lead to fire accidents. It is necessary to judge a battery with insufficient insulation resistance as a defective battery.
Object
Detection of defective products in lithium battery production lines.
Defective product detection when assembling lithium battery modules.
Question
The decrease in insulation resistance is usually caused by the contamination of metal foreign objects or the rupture of the separator during the production process. In this case, it is necessary to capture weak voltage and current changes by means of insulation resistance tests to reliably detect defective products.
【Solution】BDD function (micro short circuit detection).
The BDD function integrates analog circuitry (peak hold) and digital sampling (5ms s) to monitor weak voltage and current fluctuations. Monitor the amount of voltage change during charging and the amount of voltage and current change in the steady state after charging, and reliably detect small changes.
Products involved: Battery Insulation Resistance Tester BT5525
Safety test: DC withstand voltage test
The hipot test is to confirm the dielectric strength of the battery. This is a test performed during a factory inspection according to the test methods specified in various standards. For lithium batteries, the test voltage is generally carried out by DC voltage.
Object
Withstand voltage test performed on the production line of lithium batteries.
Check the withstand voltage between the cell, module, battery pack electrode and housing of the lithium battery.
Question
In order to ensure the safety of the battery, the electrodes (positive and negative) and the housing need to be sufficiently insulated to prevent abnormal heating caused by foreign objects and soldering burrs,** and battery deterioration. Strict withstand voltage testing is carried out at the time of factory inspection to confirm the insulation performance of the battery. Therefore, it is necessary to use a tester that meets the following conditions:
Solution
The ST5680 is a power supply that meets the requirements of various international standards for DC withstand voltage testing. In addition to the test of several mA, it can also meet the requirements of Class A small current test as the insulation performance of the battery improves. Provide stable and reliable detection to improve the reliability of battery quality.
Products involved: DC withstand voltage insulation resistance tester ST5680
Welding quality check in the production process
Most of the metal parts of lithium batteries are welded, while copper and aluminum are difficult materials to weld, and high-quality welding needs to be completed while preventing spatter. The welding quality has a great impact on the quality of the battery, and the resistance of the part that is not sufficiently welded is large when it is energized, which will generate heat, resulting in reduced battery capacity efficiency or rapid aging.
Object
Welding quality inspection in the welding process of lithium battery production lines.
Traceability in welding quality checks.
Question
Although the quality of the weld is inspected by various methods, there are some problems. At present, there are few ways to non-destructively detect minor defects inside a weld. In addition, in the future, there will be a need for inspection methods that can meet the needs of production line automation.
Solution
The resistance is measured by an electrical signal flowing through the weld part, and the resistance value is used to determine whether it is a good product. If the welding resistance is low, it is about 10 100. The Welding Resistance Tester RM3546 is equipped with a 100 measuring range, which can measure low resistance with high accuracy with a resolution of 1N. If the welding is not sufficient, the resistance value will be higher than that of the qualified product. By detecting small differences in resistance values between good and defective products, it is possible to determine whether a product is qualified or not.
Products involved: Welding Resistance Tester RM3546