The GCD profiles (Figure ) support the findings of CV, which demonstrate that the device's capacity under "positive" voltage is significantly lower compared to "negative" voltage. The charging and discharging time of the system under negative polarization is 175 s at 1 A g -1 , whereas only 0.5 s is required for charging and discharging under blocked polarization, confirming the excellent capacity rectification of the proposed system. The associated rectification ratios of the device are calculated and displayed in Figure . Significant RI and RII values of 58.7 and 95 % (at 2 mV s -1 ), respectively, are achieved, confirming the diode-like characteristics of the device and its ability to rectify current while maintaining energy storage properties. Furthermore, for analyzing the ability of the device to store energy only under a "negative" voltage, the reaction mechanism of the device is tested through in situ electrochemical measurements. In addition to the WE/CE in the CAPode device, a RE was added to simultaneously monitor the potential of both, the WE and CE electrodes during the charging and discharging process (setup Figure ). The black dashed line represents the device's voltage response (GCD profile), while the red and blue lines represent the potential distribution of the WE and CE, respectively, from OCV (-0.5 V) to -1 V (Figure ) and from OCV (-0.5 V) to -1.5 V (Figure ). Additionally, to further confirm the mechanism (intercalation steps) the scan rates were calculated based on the rate of potential changes during the discharge step, and the CV technique was employed separately for WE and CE (in 3electrode setup; Figure ) to investigate the current response of both electrodes (Figure ).