Porous boron-doped diamond (PBDD) electrode with a high potential window, excellent stability, controllable conductivity, enhanced specific area, and tunable surface termination is a promising electrode material for the candidate. The surface termination of the PBDD electrode is easily tuned by the cyclic voltammetry (CV) scanning process with a positive potential, and an oxygen-terminated (OT) surface is achieved. The OT PBDD electrode exhibits a peak specific capacitance of 20.31 mF cm⁻² (38.3% increase compared with the HT PBDD electrode, at 100 mV s⁻¹) when 2.4 V (vs. Ag/AgCl) potential is applied, and it further comes to 36.74 mF cm⁻² (81.8% increase than the HT PBDD electrode, at 10 mV s⁻¹) with a 2.7 V (vs. Ag/AgCl) polarization potential. As the polarization voltage further increases to 3.0 V (vs. Ag/AgCl) or higher, the specific capacitance decrease. The OT PBDD electrode also keeps capacitance retention of 94.8% after 6000 CV cycles at 200 mV s⁻¹. Moreover, we built up a symmetric device using the OT PBDD as the electrode, which exhibits good electrochemical performance, such as wide potential, high energy density (15.1 Wh kg⁻¹), and high power density (4.05 kW kg⁻¹).

多孔硼掺杂金刚石（PBDD）电极具有高电势窗口，出色的稳定性，可控制的电导率，增加的比表面积和可调节的表面终止能力，是候选的有希望的电极材料。PBDD电极的表面端接可通过循环伏安（CV）扫描过程轻松地以正电位进行调整，从而获得氧封端（OT）表面。当施加2.4 V（vs. Ag / AgCl）电位时，OT PBDD电极的峰值比电容为20.31 mF cm ^-2（与HT PBDD电极相比，在100 mV s ^-1处增加38.3％），并且进一步在10 mV s ^-1时达到36.74 mF cm ^-2（比HT PBDD电极增加81.8％），极化电位为2.7 V（vs. Ag / AgCl）。随着极化电压进一步增加到3.0 V（vs. Ag / AgCl）或更高，比电容降低。OT PBDD电极在200 mV s ^-1下经过6000 CV循环后，还能保持94.8％的电容保持率。此外，我们构建了一种以OT PBDD作为电极的对称器件，该器件具有良好的电化学性能，如宽电势，高能量密度（15.1 Wh kg ^-1）和高功率密度（4.05 kW kg ^-1）。