The electrons can not be stored stationary floating in the vacuum of the bottle. They will immediately attach to the internal surface. The entire bottle is now negatively charged and will accumulate positive charge on the external surface until it is electrically neutral. Now you have a funny looking capacitor with extra steps.
The closest thing in existence are the magnetic bottles used for different fusion reactor designs and particle accelerators. In these, the charged particles are kept moving in a closed loop contained by electromagnets that contiously adjust to keep the system pseudo-stable. These certainly cant store energy.
The electrons can not be stored stationary floating in the vacuum of the bottle. They will immediately attach to the internal surface. The entire bottle is now negatively charged and will accumulate positive charge on the external surface until it is electrically neutral. Now you have a funny looking capacitor with extra steps.
The closest thing in existence are the magnetic bottles used for different fusion reactor designs and particle accelerators. In these, the charged particles are kept moving in a closed loop contained by electromagnets that contiously adjust to keep the system pseudo-stable. These certainly cant store energy.