Cathode is positive and therefore would be expected to repel the positively charged cations; this is due to electrode potential relative to the electrolyte solution being different for the anode and cathode metal/electrolyte systems in a galvanic cell). The cathodic current, in electrochemistry, is the flow of electrons from the cathode interface to a species in solution. The anodic current is the flow of electrons into the anode from a species in solution. In an electrolytic cell, the cathode is where the negative polarity is applied to drive the cell. Common results of reduction at the cathode are hydrogen gas or
Electrolytic capacitor are therefore smaller than aluminium electrolytic capacitors. In practice different safety margins to reach reliable components makes a comparison difficult. The anodically generated insulating oxide layer is destroyed if the polarity of the applied voltage changes. Electrolytic capacitors are based on the principle of a "plate capacitor" whose capacitance increases with larger electrode area A, higher dielectric permittivity ε, and thinner dielectric (d). The dielectric thickness of electrolytic capacitors is very small, in the range of nanometers per volt. On the other hand, the voltage strengths of these oxide layers are quite high. With this very thin dielectric oxide layer