Transition metal oxides (TMOs) suffer from inherently low electronic conductivity, while atom orbital related regulation can be critical to promote the electron transfer kinetics in energy storage applications. Herein, the study utilizes a d–π conjugation strategy to improve the electronic conductivity of TMOs. Briefly, phthalocyanine (Pc) molecules with large conjugated systems are selected to modify transition metal oxide (δ-MnO₂). By density functional theory (DFT) simulations, it is clarified that the strong d–π conjugation between MnO₂ and Pc can elevate the orbital energy level of low energy orbital (d_xy) in MnO₆ units, which further activates the redox activity of d_xy. The delocalized π electrons from Pc to MnO₆ unit repel the original d_xy electrons, and then elevate the d_xy orbital energy level, thus facilitating the electron transfer in MnO₂-Pc. Subsequently, the MnO₂-Pc exhibits a significant specific capacitance of 310 F g⁻¹ at 1 A g⁻¹. At a power density of 900 W kg⁻¹, the fabricated asymmetric supercapacitor delivers a maximal energy density of 50.3 Wh kg⁻¹. This work paves the way to boost the redox activity of transition metal center in TMOs by regulating the orbital energy level, which can be expanded to design other advanced energy materials.

中文翻译：

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通过 d-π 共轭提高 MnO6 中 dxy 的轨道能级，实现卓越的钠存储性能

过渡金属氧化物（TMO）固有的电子电导率较低，而原子轨道相关的调节对于促进储能应用中的电子转移动力学至关重要。在此，该研究利用d-π共轭策略来提高 TMO 的电子电导率。简而言之，选择具有大共轭体系的酞菁（Pc）分子来修饰过渡金属氧化物（δ -MnO ₂）。通过密度泛函理论（DFT）模拟，阐明了MnO _{2和Pc之间的强}d-π共轭可以提高MnO _{6中低能轨道（} d _xy ）的轨道能级单位，进一步激活d _xy的氧化还原活性。从Pc到MnO ₆单元的离域π电子排斥原来的d _xy电子，然后提升d _xy轨道能级，从而促进MnO ₂ -Pc中的电子转移。随后，MnO ₂ -Pc在1A g ^{-1下表现出310 F g -1}的显着比电容。在功率密度为900 W kg ⁻¹时，所制造的非对称超级电容器的最大能量密度为50.3 Wh kg ⁻¹。这项工作为通过调节轨道能级来提高TMO中过渡金属中心的氧化还原活性铺平了道路，并且可以扩展到设计其他先进能源材料。