Anode to what occurs in an electrolytic cell, no anions flow to the anode, the internal current being entirely accounted for by the cations flowing away from it (cf drawing). In the United States, many battery manufacturers regard the positive electrode as the anode, particularly in their technical literature. Though technically incorrect, it does resolve the problem of which electrode is the anode in a secondary (or rechargeable) cell. Using the traditional definition, the anode switches ends between charge and discharge cycles. In electronic vacuum devices such as a cathode ray tube, the anode is the positively charged electron collector. In
SAL electrolytic capacitor 31, 2015 these are now end-of-life and have ceased production. Basic anode material of solid aluminum capacitors exists of highly purified aluminum with a purity of at least 99.99%. In an electrochemical process the anode material is etched (roughened) to increase the effective electrode surface. After that the roughened aluminum becomes oxidized or formed by an anodic oxidizing process. Thereby an electrical insulating oxide layer AlO is formed on the aluminum surface by applying an electric current in correct polarity in an electrolytic bath. This process of oxide formation is carried out into two reaction steps: The aluminum oxide layer