Composite membrane, preparation method thereof, and lithium-air battery including the composite membrane

A lithium secondary battery comprising:

• an anode;
• and
• a composite membrane on the anode, wherein the composite membrane comprises
• an lithium-ion-conductive region comprising ion conductive inorganic particles having an average particle diameter in a range of about 10 micrometers to about 300 micrometers, and
• a lithium-ion non-conductive region comprising a polymer layer, wherein the lithium-ion non-conductive region has barrier properties effective to block a gas, moisture, or a combination thereof,
• wherein a thickness of the ion conductive inorganic particles is greater than a thickness of the polymer layer,
• wherein the thickness of the ion conductive inorganic particles is a dimension between a top surface and a bottom surface of the ion conductive inorganic particle, regardless of the shape of the ion conductive inorganic particle, and
• wherein the anode comprises Li metal, a Li alloy, or a combination thereof.