In this study, six types of nanocellulose, as paper strengthening agents, were investigated for their reinforcing effects on a supercapacitor membrane by adding them to a slurry. The results indicated that adding 3% nanocellulose bacterial cellulose (BC)-B could effectively increase the tensile strength of the supercapacitor membrane by 36.5% without changing the pore structure of the membrane. Scanning electron microscopy images revealed that adding polyacrylamide to the supercapacitor membrane caused serious adhesion between fibers and affected the pore structure of the supercapacitor membrane, whereas adding BC-B did not produce similar effects.