Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been
conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different
structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with
small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures
(22–50 °C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent
of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand
formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are
formed under 10 V at the beginning of the anodization and then serve as a template layer dominating the
formation of ultra-small nanopores. Anodization that is performed at voltages less than 5 V leads to mesh
structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls
of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films
in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte