The invention relates to the technical field of cylindrical
lithium ion battery production, and discloses a method for detecting insufficient
welding of a cylindrical
lithium ion battery, and the method comprises the following steps: S1, appearance inspection; s2, initial
internal resistance benchmark test; s3, applying a short-time large-
current pulse to the battery by using a
pulse generator, simulating an actual load condition, and recording an instantaneous
voltage drop and current response curve of the
voltage of the battery end during the
pulse period; s4, performing
infrared thermal imaging identification and
data processing; s5, learning the picture and establishing a model; s6, comparing the test picture and the data with the model; s7, dynamic
internal resistance calculation; s8, cold solder joint query and sorting
processing; and S9, retesting the
electrical performance. According to the invention, the technologies of dynamic
internal resistance measurement, nondestructive X-
ray or
ultrasonic detection, rate
discharge test and the like are adopted, so that efficient, accurate and nondestructive detection of the cold solder joint of the cylindrical
lithium ion battery is realized, and the production efficiency and the detection precision are remarkably improved.