Performance of through-hole anodic aluminum oxide membrane as a separator for lithium-ion battery

• Through-hole AAO membrane with the thickness of 60 μm and high porosity of 72% is prepared.
• The AAO separator infiltrated with electrolyte exhibits high ionic conductivity.
• The as-prepared AAO membrane is used as a separator for lithium-ion batteries.
• The batteries using the AAO separators show excellent electrochemical properties.

A high porosity through-hole anodic aluminum oxide (AAO) membrane has been prepared by a two-step anodization procedure. The as-prepared AAO membrane is around 60 μm thick with a uniform pore size of about 80 nm. Moreover, we also found that the AAO membrane not only has a good mechanical strength but also shows better performances on electrolyte infiltration and retention compared with the commercial polymer separator. The LiFePO4/graphite battery using the AAO separator exhibits better cycling stability, rate capability and low-temperature performance than those using the polymer separators. The excellent electrochemical performances can be attributed to good hydrophilic characteristic, high porosity and through-pore structure of the AAO separators used. Therefore, the AAO separator is very promising to be applied in lithium-ion batteries.