Abstract: The high-accuracy measurement on lithium-ion battery polepiece coating thickness is the prerequisite for good regulation. To satisfy the need of dynamic, non-contact and high-precision measuring, the online measuring system was designed that based on micrometric displacement measuring by non-contact capacitive sensor. The structure and circuit of sensor is introduced, the hardware system suitable for lithium-ion battery polepiece coating thickness measurement is constructed, and the practical testing system based on the virtual instrument technology for data sampling, linear correction and data record is developed. Through the experiment, the resolution of the sensor is 0.1um. By long running in measurement scene, it is proved that the system can meet the production requirements of measurement.

Key words: Coating thickness, Capacitance sensor, On-line measurement, Virtual technology