Pipelines are used for charging and discharging power in a redox flow battery (RFB). Inner tube made of ion-exchange material is inserted into each of the pipelines. Conductive sleeves are installed on inside and outside the inner tube. Anode electrolyte and cathode electrolyte flow into corresponding ones of the pipelines of the inner tube. Thereby, wires connected with the conductive sleeves are extended out to be used as electrodes. On charging power, the anode electrolyte and the cathode electrolyte flow forwardly; yet, on discharging power, the anode electrolyte and the cathode electrolyte flow backwardly. Thus, the present invention uses pipelines to add or supplement function of charging/discharging power. Even when the RFB is damaged or failed, power is still charged/discharged for effectively improving or ensuring efficiency of the battery.