Kirk Smith, PhDI made a sub-5-minute video of myself building a flow battery and starting a test!
It's on PeerTube, ofc:
PeerTube
Aleksandr Koltsoff@kirk Nicely done and clean separation of phases.
A silly question perhaps but why is there a "dip" in the change of voltage at the start? I'd expected somewhat more uniform logarithmic graph.
@nihkeys thank you! I'm trying to practice my video editing and be less perfectionist about things and just get them out there!
Re. the weird dip - it can be a number of things, I usually attribute it to an irreversible side reaction with some impurities that are inherently present in the mixture, like something getting reduced/oxidised before the intended reaction occurs. For ex, my zinc chloride is only 98.5% purity. This current is fairly low, if you increase the current then you won't see this behavior since it will "jump" straight to the charging plateau -- the charging protocol is forcing a certain amount of current, and past a point there isn't enough of the undesirable reaction and the voltage jumps up to the main plateau. This often goes away on subsequent cycles.
Here is a screenshot of the current cycle from that video, you can see that initial dip is insignificant compared to the rest of the cycle:
