US 11,852,457 B2
Contactless method for polymer coating thickness measurement
Fang Dai, Troy, MI (US); Hongliang Wang, Sparks, NV (US); Shuru Chen, Troy, MI (US); and Mei Cai, Bloomfield Hills, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Dec. 20, 2021, as Appl. No. 17/556,430.
Prior Publication US 2023/0194242 A1, Jun. 22, 2023
Int. Cl. G01B 11/06 (2006.01); H01M 4/02 (2006.01); H01M 4/62 (2006.01); H01M 10/052 (2010.01); H01M 4/38 (2006.01)
CPC G01B 11/0641 (2013.01) [H01M 4/382 (2013.01); H01M 4/62 (2013.01); H01M 10/052 (2013.01); H01M 2004/027 (2013.01); H01M 2220/20 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A system for measuring a thickness of a coating arranged on an anode substrate, the system comprising:
an optical measurement system configured to transmit a light signal toward the anode substrate through the coating such that the light signal is reflected from the surface of the anode substrate,
wherein the light signal has a known first polarization, and
wherein the anode substrate is a flexible lithium metal anode and the coating is a polymer coating;
a detection module positioned to receive the reflected light signal and configured to (i) determine a second polarization of the reflected light signal, wherein the second polarization is different from the first polarization and (ii) measure a polarization difference between the first polarization and the second polarization; and
a measurement module configured to receive the measured polarization difference, calculate the thickness of the coating based on the measured polarization difference, and generate an output based on the calculated thickness.