The production of metal-free electrodes for textile-based triboelectric nanogenerators (TENGs) is an important strategy to preserve the intrinsic properties of unmodified textiles with good conductivity levels. Herein, polyaniline-modified cotton fibers were applied as electrodes for TENGs and a protonation-degree dependence was controlled to improve the power output of the device, which reached a maximum value of 71 μW and an open circuit voltage of 174 V.