The 'oil' is kerosene, some old partially polymerised stuff that definitely has some aldehydes based on reaction with NaOH.
Nothing was pre-prepared, I just did it to see what will be required to do it 'properly'
Most of the corrosion is due to air, I undid the battery under kerosene,
even when oily (keroseney ?) a brief exposure to air blackens the surface.
Most of the foil remained shiny but I exposed the entire foil to air when I rolled it up to fit the test tube.
A little of the corrosion does seem due to 'stuff' in the kerosene.
(aldehydes, water, oxygen, nitrogen ?)
I initially stored the test tube upside down to keep the lithium below the kerosene,
but some small bubbles slowly formed
and I started to imagine a lithium/kerosene rocket |