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CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

(www.lumafield.com)
287 points jonbruner | 1 comments | 24 Sep 25 19:29 UTC | HN request time: 0.209s | source
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progbits ◴[24 Sep 25 22:16 UTC] No.45366609[source]▶
To save everyone the hassle of filling out the "get the report" form:

https://7802750.fs1.hubspotusercontent-na1.net/hubfs/7802750...

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gertlex ◴[27 Sep 25 00:22 UTC] No.45392358[source]▶
FWIW I found the report's summary (a few days ago when this was also discussed) essential for clarifying for me what the linked "article" was talking about regarding "anode overhang" and "edge alignment".

To summarize it myself, the battery is cylindrically wrapped sheets of anode/cathode material, and you want the top edge to have a straight line consistently having the anode layers (|) sticking out beyond the cathode layers ()

edit: Welp, the unicode I illustrated with got stripped out; so trying again with pipes

    anode
     cathode
      a a
       c c
    | | |
    ||||||
The pics with red and blue dots didn't immediately make this obvious to me, but made sense once I understood the "overhang" meaning.
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MBCook ◴[27 Sep 25 01:15 UTC] No.45392580[source]▶
So the big danger here is an internal short being far more likely?
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1. gertlex ◴[27 Sep 25 04:14 UTC] No.45393169[source]▶
That was my general sense. And that "nominal" is really easy to identify visually with a (relatively slow) scan. I'd guess that means it's a clear quality control thing you (i.e. battery pack makers who are buying the cells) can expect the better manufacturers to do, and pay a slight premium for.