An electrochemical cell includes: an electrode assembly; and a housing including a first sheet and a second sheet, wherein the first sheet includes a first gas blocking layer, and a first sealing layer, and wherein the second sheet includes a second gas blocking layer and a second sealing layer, wherein the housing defines an accommodation region which accommodates the electrode assembly, which is disposed between the first sheet and the second sheet, and wherein the housing includes a bonded member, wherein the bonded member includes a third gas blocking layer disposed between the first gas blocking layer and the second gas blocking layer, wherein the third gas blocking layer includes a plurality of nanostructures.