A cathode's an electrode through which electric current flows out of a polarized electrical device. Mnemonic: CCD (Cathode Current Departs).A widespread misconception's that cathode polarity's always negative. This's often incorrectly inferred from the correct fact that in all electrochemical devices positively charged cations move towards the cathode (whence their name) and/or negatively charged anions move away from it. In fact cathode polarity depends on the device type, and can even vary ac… (More on Cathode)