To enhance chlorine ion removal and increase the current charging capacity of a desalination battery system, carbon nanotubes were applied to a carbonaceous electrode. Two types of composite electrodes were fabricated by attaching multiwalled carbon nanotubes (MWCNTs) to a carbon felt (CF) electrode via dip coating (D-CNT@CF) and electrophoresis (E-CNT@CF). These composite electrodes were then tested within a desalination battery system to evaluate their chlorine ion removal efficiency and current charging performance during the charging process. Microflocs of MWCNTs were observed on the surface of D-CNT@CF, whereas a uniform coating of MWCNTs was achieved on the surface of E-CNT@CF. Performance evaluations revealed that chlorine ion removal rates improved by 3.5% for D-CNT@CF and by 19.4% for E-CNT@CF compared to that of CF. Furthermore, the time required to reach maximum current charge was 40.0% for D-CNT@CF and E-CNT compared to CF. @CF decreased by 60.0%. These findings suggest that surface modification of carbonaceous electrodes through electrophoresis can result in a more stable coating and improve the performance of desalination battery systems.