I feel like timeshell is correct... You have resistance and reactance in the cell this is why it will never behave like a conventional LC tank circuit.. Its over damped cause of the existence of R in the cell.. Makes it s parallel RC circuit of sorts..
But in this case the R exist in the same space as C. they are in the same component..
When I have done test with a lcz meter on a cell it DOES NOT behave like you would want it to match the idea of parallel RC.. Its actually inversed.. You would think that as freq increased the phase angle would increase and the cell would pass more power into the reactive component and less power into the resistive component of the cell.. But based on the lcz meter this is opposite.. It shows the phase angle increases as you lower the frequency. The capacitance value of the cell increases a lot as you lower the frequency as well.. which is not normal for a pure capacitor to do.
A pure capacitor having a pure dielectric would maintain close tolerance of capacitance reading at all test freqs. Spring water does not.
The only thoughts I can come up with this situation is that this parallel RC has another feature that differs from a conventional parallel RC circuit. It is a liquid dielectric with electrolytes. This allows for things like a hemholtz layer to form on the electrode... A form of electrochemical storage of power with the ionic contaminates occurs they refer to as pseudo capacitance.
Pseudo capacitance may be what the LCZ meter is presenting as I lowered the test frequency.. The lower frequency would allow more time for ion collection to occur at the electrodes during the test. also a false appearance of increased capacitance.
A water cell has a poor power factor.. There are losses in it from resistance but if there is a way to produce a great amount of fuel with a poor power factor that's ok because this capacitor is not just a capacitor for storing and processing power in a circuit. Its a material processor as well. Its expected to have some losses and consume energy in the production of fuel.
https://en.wikipedia.org/wiki/Pseudocapacitorhttps://en.wikipedia.org/wiki/Double_layer_(surface_science)