Porous anodic alumina (PAA) films have become popular nanotemplates due to the ordered hexagonal pore array structure. The fabrication of well-ordered PAA films with larger interpore distances is still a challenge to date. Here, we develop a unique electrolyte system based on the reaction products of ethylene glycol (EG) with ammonium dihydrogen phosphate (ADP). In the novel electrolytes, stable high-voltage anodization with extremely high current densities (the peak value is close to 300 mA cm(-2)) can be realized at 400 V or even higher without breakdown. In 5 wt% EG-ADP-based electrolyte containing phosphoric acid, a well-ordered PAA film with an interpore distance of similar to 610 nm can be fabricated at 250 V at a high growth rate of 1.3 mu m . min(-1). (C) 2018 The Electrochemical Society.