Electrofishing uses direct current electricity flowing between a submerged cathode and anode. Dendrites penetrate the separator between the anode and the cathode causing short circuits. The Ignatron had a cathode, anode and an igniter. Tantalum electrolytic capacitors with PPy polymer electrolyte cathode followed three years later. This is because the distance between the cathode and anode is relatively small. An electrolyte acts as the cathode of electrolytic capacitors. Therefore, the concepts of cathode and anode do not apply. The VFD uses phosphor-coated anodes as in other display cathode ray tubes. It stored data as electrically charged spots on the face of a cathode ray tube. Copper(II) ions migrate through the electrolyte to the cathode. The ions travel through the electrolyte to the cathode. Positively charged ions (cations) move towards the electron-providing (negative) cathode. Another method is electrolysis of ferrous chloride onto an iron cathode. The starting method and frequency affects cathode sputtering. Wh/L when paired with a lithium cobalt oxide cathode.