Interesting question, and I don't know. There very may be electro-chemical reasons, for example 316 stainless has a lot better sodium corrosion resistance than 304 ss.
Just a wild guess but the polarity may have something to do with the choice of alloy.
Intriguing.
Speaking of alloys Charles, try analyzing the metals used in a household incandescent bulb- a tremendous amount of research in materials led to metals with just the right mechanical/physical compatibilities.
Good question, based upon a really good observation.
Geo
----- Original Message -----
From: Nick Andrews <nickjandrews@...>
To:
[email protected]Sent: Sun, 09 Feb 2020 10:59:11 -0500 (EST)
Subject: Re: [XRF] Li battery shiny vs dull
Probably just more Cr in the alloy used.? Possibly for corrosion resistance.? Or the metal on that side is thicker,? as it's the primary casing of the unit.?
Just for fun I tested both sides of a Li battery.? One side (+) is shiny and engraved and the other side is dull (-).? After doing the shiny side (red) for a couple of hours I started the dull side and unfortunately let it run overnight so the counts are disproportionately high.? However, close inspection of the 2 graphs show that the shiny side has much more Cr than the dull side.? In fact, whatever Cr shows up in the blue graph may actually be coming from the edges of the battery where the shiny side wraps around.
So my question is whether there is an electrical reason for the Cr on the + side or is it purely cosmetic?
Charles
