I am starting experiments in the field of Li-ion batteries so I start my experiments with a first "basic" graphite (working electrode) half-cell with Lithium disk as counter and reference electrodes before starting with my own anode materials.

My problem is that I observe sudden jumps of current during the scanning of the cyclic voltametry (CV). Generally the CV starts well, during one/two hours at 0.2 mV.sec -1 and then I can observe this sudden current jump that do not seems to be related to a electrochemical reaction as I am able to keep the expected electrochemical peaks of graphite even with those current jump. Generally, after a while I observe a jump back to the normal expected current and some others jump can occurs during the rest of the CV. So the CV is a mess at the end.

So I have doubt about the way I am preparing the nutclock cell:

I am using the smaller pole (the one with a reduction of diameter)+the cap with longer electrical contact (A) for the Lithium side. Generally I tried to put some drops (1 to 3 drops) of electrolyte on the Lithium disk positioned on the smaller pole already installed in the cap A with the teflon cylinder also in place (screwed on cap A). During this time I leave the membrane in the electrolyte to wet it and then I put it on the lithium disk. Then I add 2 to 3 drops of electrolyte on the membrane and add the graphite electrode. Finally I lose the system by putting in place the second pole and the cap B screwed on the teflon cylinder. I apply a parafin foil around the whole cell.

I do not use sealings and I use only one Celgard membrane. Should I use two membranes ?

I am not sure about how strong I have to screw the cap B once all the electrodes are in place ?? Should I gently screw or strongly screw (I tried both without any effect)?

Should I add more electrolyte (I am a bit concerned about the fact that some electrolyte could be in between the back side of the electrode(s) and the pole(s) and then deteriorate the electrical current.....)

I am doing the CVs into the glove box that the reason why I am not using the sealings (values into the gliove box:H2O < 10 ppm, O2