It is of great importance to rationally design and fabricate electrode materials with high utilization and unexceptionable re-cycling performance in energy storage device including supercapacitors (SCs). Herein, Mn-doped Ni(OH)₂ nanosheets with oxygen vacancies in-situ grow on the Co₃O₄ nanorods on carbon cloth (CC) to form a core–shell heterostructure (Co₃O₄@Mn-Ni(OH)₂/CC). The obtained Co₃O₄@Mn-Ni(OH)₂/CC electrode has an outstanding specific capacity of 313.4 mA h g⁻¹ (1128.4C g⁻¹ or 2051.6F g⁻¹) at 1 A g⁻¹, ca. 6.4 times that of the Ni(OH)₂/CC electrode (48.9 mA h g⁻¹). The hybrid supercapacitor (HSC) constructed by activated carbon (AC) and Co₃O₄@Mn-Ni(OH)₂/CC displays a marvelous energy density of 65.5 W h kg⁻¹ at 800 W kg⁻¹, and 93.0% of the capacity retention over 10,000 repeated charging/discharging cycles at 5 A g⁻¹, superior to the Co₃O₄@Ni(OH)₂/CC//AC HSC (36.5%) and Mn-Ni(OH)₂/CC//AC HSC (53.9%). The results of the characterizations and density functional theory (DFT) calculation show that the Mn-doping and subsequent induced oxygen vacancies promote the conductivity, and inhibit the irreversible phase transition of Ni(OH)₂ during the charging/discharging process which contributes to the long-time cycling stability of the electrode. Moreover, the core–shell heterostructure fosters the exposure of active sites and reduces the charge transfer resistance due to the interfacial interaction. This work provides some insight into the rational design and fabrication of electrode materials with high utilization in SCs.

在包括超级电容器（SC）在内的储能装置中，合理设计和制造具有高利用率和良好的再循环性能的电极材料具有重要意义。在此，具有氧空位的 Mn 掺杂 Ni(OH) _{2纳米片在碳布 (CC) 上的 Co 3} O ₄纳米棒上原位生长，形成核壳异质结构 (Co ₃ O ₄ @Mn-Ni(OH) ₂ /抄送）。所得Co ₃ O ₄ @Mn-Ni(OH) ₂ /CC电极在1 A g ^{-1下具有313.4 mA h g -1} (1128.4C g ^-1或2051.6F g ^-1 )的优异比容量，约 是Ni(OH) ₂ /CC电极(48.9 mA h g ^-1 )的6.4倍。由活性炭 (AC) 和 Co ₃ O ₄ @Mn-Ni(OH) ₂ /CC 构成的混合超级电容器 (HSC)在 800 W kg ^-1时显示出惊人的 65.5 Wh kg ^-1能量密度和 93.0%在 5 A g ⁻¹下超过 10,000 次重复充电/放电循环的容量保持率优于 Co ₃ O ₄ @Ni(OH) ₂ /CC//AC HSC (36.5%) 和 Mn-Ni(OH) ₂/CC//AC HSC (53.9%)。_{表征和密度泛函理论 (DFT) 计算的结果表明，Mn 掺杂和随后诱导的氧空位促进了导电性，并抑制了 Ni(OH) 2}在充电/放电过程中的不可逆相变，这有助于电极的长期循环稳定性。此外，核壳异质结构促进了活性位点的暴露，并降低了由于界面相互作用引起的电荷转移阻力。这项工作为 SCs 中高利用率电极材料的合理设计和制造提供了一些见解。