Many electronic devices may employ electrolytic polymer capacitors in their power supplies for noise filtering, decoupling/bypassing, frequency conversion and DC-DC and AC-DC conversion. However, some polymer capacitors exhibit an anomalous charging current phenomenon, which may prevent proper charging and cause failure in power circuits of the electronic devices. Disclosed herein are polymer capacitors that have a wide band gap material layer between an insulator/dielectric and a polymer cathode, a charge depletion region in the insulator/dielectric, or both, that may mitigate the anomalous charging current.