That would be a stupidly hight amount of charge.

For a very rough estimate, thunderstorms peak at about 6.7 nanocoulombs of charge per m³, or 4.2e10 fewer electrons per m³. Cumulonimbus clouds have roughly 2 grams of water per m³, or 6.7e22 atoms per m³. Thus, thunderstorms have 1 in 10e12 fewer electrons.

To fully ionize water, you would need something like a trillion times as much voltage as lightning, and the ability to insulate the sample from other sources of electrons like any nearby matter.

This might be feasible at very small scales, but the result would be just as dangerous. A bunch of protons that really want electrons nearby would pull lightning from anywhere they could, and would be unbelievably corrosive. Something like a pH of -23.7, although pH breaks down long before this point.

Such a substance completely devoid of electrons would also repel itself very strongly, so it would evaporate into gaseous protons basically instantly. "Normal" plasma is much more stable because the electrons are separated by temperature rather than by electric change. High electric charges are much more difficult to contain.

I'm not a physicist though, so I'm likely wrong on the details.