Why are electrolytic capacitors unipolar?
The dielectric is an integral anodic coating produced in situ on the electrode such as aluminum foil , tantalum foil or a porous sintered tantalum pellet by electrolysis, which is why the nameIn the capacitor a tin film of the electrolyte remains in contact with the dielectric, which therefore becomes self repairingIf the polarity is reversed the dielectric will disappear because it is now the cathodeIt is possible to make an AC electrolytic capacitor by having both electrodes to have the coatingThis is not very effective and the main advantage of compactness of the electrolytic is compromised.
