Vacancy defects have important impacts on the physical-chemical properties of metal oxides. In the present work, two types of Bi₂O₃ powders with different morphologies were synthesized for supercapacitor electrodes by calcination (denoted as c-Bi₂O₃) and two-step hydrothermal methods (donated as h-Bi₂O₃). Vacancy clusters of $V_{Bi}^{,}{V}_O^{··}{V}_{Bi}^{,}$ with different concentrations were observed in these two samples by positron annihilation lifetime spectroscopy. The results of electrochemistry revealed that the charge storage behavior of h-Bi₂O₃ with more $V_{Bi}^{,}{V}_O^{··}{V}_{Bi}^{}$ defects obeyed both semi-infinite diffusion-controlled battery-type mechanism and surface-controlled pseudo-capacitance mechanism, while that of the calcined c-Bi₂O₃ electrode with a lower concentration of $V_{Bi}^{,}{V}_O^{··}{V}_{Bi}^{,}$ defects followed only the semi-infinite diffusion-controlled battery-type mechanism. The pseudo-capacitance of h-Bi₂O₃ could be attributed to the insertion/extraction process of more K⁺ ions in the $V_{Bi}^{,}{V}_O^{··}{V}_{Bi}^{,}$ surface defects. Due to the partial pseudo-capacitance and improved conductivity caused by more $V_{Bi}^{,}{V}_O^{··}{V}_{Bi}^{,}$ defects, the h-Bi₂O₃ electrode had a larger capacitance (1043 F g^-1 at 1 A g^-1), a higher rate performance (560 F g^-1 at 60 A g^-1), and better cycle stability (93% retention at 50 A g^-1 after 2000 cycles). Furthermore, because of the high-concentration of $V_{Bi}^{,}{V}_O^{··}{V}_{Bi}^{,}$ defects, the Ni/Co-MOF//h-Bi₂O₃ asymmetric supercapacitor delivered a relatively higher specific energy density of 47 Wh kg^-1 at 1125 W kg^-1. Taken together, these results indicate that surface vacancy clusters play an important role in boosting the electrochemical performance of metal oxide electrodes.

空位缺陷对金属氧化物的物理化学性质有重要影响。在本工作中，通过煅烧（表示为c-Bi ₂ O ₃）和两步水热法（捐赠为h-Bi ₂ O ₃）合成了两种类型不同形态的Bi ₂ O ₃粉末用于超级电容器电极。的空缺集群$V_{乙\mathrm{一世}}^{，}{V}_{Ø}^{··}{V}_{乙\mathrm{一世}}^{，}$通过正电子an没寿命光谱法在这两个样品中观察到了不同的浓度。电化学的结果表明的电荷存储行为H-的Bi ₂ ö ₃与更$V_{乙\mathrm{一世}}^{，}{V}_{Ø}^{··}{V}_{乙\mathrm{一世}}^{}$缺陷同时遵循半无限扩散控制的电池型机理和表面控制的伪电容机理，而煅烧的c-Bi ₂ O ₃电极的缺陷浓度较低。$V_{乙\mathrm{一世}}^{，}{V}_{Ø}^{··}{V}_{乙\mathrm{一世}}^{，}$缺陷仅遵循半无限扩散控制的电池型机制。h-Bi ₂ O ₃的假电容可归因于更多K ⁺离子的插入/萃取过程。$V_{乙\mathrm{一世}}^{，}{V}_{Ø}^{··}{V}_{乙\mathrm{一世}}^{，}$表面缺陷。由于部分伪电容和电导率提高引起的更多$V_{乙\mathrm{一世}}^{，}{V}_{Ø}^{··}{V}_{乙\mathrm{一世}}^{，}$缺陷时，H-Bi系₂ ö ₃电极有较大的电容（1043 F G ^-1 1 A G ^-1），较高速率的性能（560 F G ^-1在60 A G ^-1），以及更好的循环稳定性（2000次循环后，在50 A g ^-1下的保留率为93％）。此外，由于高浓度的$V_{乙\mathrm{一世}}^{，}{V}_{Ø}^{··}{V}_{乙\mathrm{一世}}^{，}$缺陷，Ni / Co-MOF // h-Bi ₂ O ₃不对称超级电容器在1125 W kg ^-1时提供了相对较高的47 Wh kg ^-1的比能量密度。综上所述，这些结果表明表面空位簇在增强金属氧化物电极的电化学性能中起重要作用。