Mystery white coating on battery terminals - intermetallic
Mystery white coating on battery terminals - intermetallic
(OP)
Hello,
I am battling with a mystery high-impedance coating that is appearing on the battery terminals of a lithium ion battery. Frankly, I'm not even sure its corrosion, but - as it's an intermetallic joint - it's my best guess so far! I've uploaded a couple of magnified photos, showing how the coating looks like after scratching the surface a little.
http://files.engineering.com/getfile.aspx?folder=b...
http://files.engineering.com/getfile.aspx?folder=7...
As well as these photos, here is some more information:
Best,
Eddie
I am battling with a mystery high-impedance coating that is appearing on the battery terminals of a lithium ion battery. Frankly, I'm not even sure its corrosion, but - as it's an intermetallic joint - it's my best guess so far! I've uploaded a couple of magnified photos, showing how the coating looks like after scratching the surface a little.
http://files.engineering.com/getfile.aspx?folder=b...
http://files.engineering.com/getfile.aspx?folder=7...
As well as these photos, here is some more information:
- I actually do not know what metal the contact is. I have asked the supplier and hope to know this Friday.
- The material of the other contact is gold. I have read a little about white plague, and purple plague, but I read that this is relevant to aluminium, and those contacts don't look like aluminium.
- The impedance of the coating must be reasonable. The contact force is normal to the surface, so there's no "scraping" action there, and the coating is preventing this 3.7V cell from being detected by the charging unit.
- I cannot discount the possibility of this being some sort of resin/flux that's leftover from an unsuited assembly process. If this doesn't look, or sound like corrosion to anyone here then this becomes the most likely possibility.
Best,
Eddie
Edward Matos
MEng (Hons.), AMIMechE





RE: Mystery white coating on battery terminals - intermetallic
RE: Mystery white coating on battery terminals - intermetallic