Semi-solid-state Al-air batteries with solid electrolytes prepared by mixing AlCl3·6H2O and various hydrophobic additives were prepared and tested. All of the prepared Al-air batteries exhibited higher current 48 hours after battery preparation. This might be due to a decrease in battery resistance as AlCl3·6H2O melted and penetrated into the air cathode as a result of its hygroscopic property. Among the batteries tested, when commercial vaseline and butyl methyl imidazolium hexafluorophosphate were mixed with AlCl3·6H2O and used as the solid electrolyte, the prepared Al-air battery exhibited a stable high current and electrochemical property.