Poor electronic conductivity and sluggish ion diffusion are the two main obstacles that limit the pseudocapacitive performance of Fe₂O₃. In this work, oxygen-deficient Fe₂O_3-δ nanorod arrays with a unique crystalline core/amorphous shell heterostructure are prepared via a facile and controllable method. The tunable amorphous layer facilitates the Li⁺ diffusion while introduced oxygen defects in Fe₂O₃ can be effectively tuned to improve electronic conductivity. More importantly, the resultant crystalline/amorphous interface greatly increases charge storage sites for improved specific capacitance. Consequently, the crystalline core/amorphous shell Fe₂O_3-δ integrated on graphene delivers a large capacitance of 701 F g⁻¹ (701 mF cm⁻²) at 1 A g⁻¹, which is almost double the capacitance of the conventional Fe₂O_3-δ nanorods without amorphous surface layer on graphene. Besides large capacitance, the electrode also exhibits greatly improved rate capability and cycle performance. To construct asymmetric supercapacitor, similar strategy is implemented to prepare Co₃O_4-δ nanosheet arrays with superior pseudocapacitive performance compared to its pristine counterpart. Importantly, flexible and large-scale (10 × 10 cm²) asymmetric supercapacitors are fabricated with promising device performance, demonstrating the smart electrode design is promising for practical application.

电子导电性差和离子扩散缓慢是限制Fe ₂ O ₃假电容性能的两个主要障碍。在这项工作中，通过一种易于控制的方法制备了具有独特的晶核/非晶壳异质结构的缺氧Fe ₂ O3 _-δ纳米棒阵列。可调节的非晶层促进了Li ^+的扩散，同时可以有效地调节Fe ₂ O _3中引入的氧缺陷以改善电子导电性。更重要的是，所得的晶体/非晶界面大大增加了电荷存储位点，从而改善了比电容。因此，结晶核/非晶壳铁集成在石墨烯上的₂ O3 _-δ在1 A g ^-1下提供了701 F g ^-1（701 mF cm ^-2）的大电容，这几乎是传统的无非晶Fe ₂ O3 _-δ纳米棒的电容的两倍。石墨烯上的表面层。除了大电容之外，该电极还展现出大大提高的倍率能力和循环性能。为了构造不对称超级电容器，实施了类似的策略以制备比其原始对应物具有优异的假电容性能的Co ₃ O4 _-δ纳米片阵列。重要的是，要灵活，大尺寸（10×10 cm ²）非对称超级电容器具有令人满意的器件性能，证明了智能电极设计对于实际应用是有希望的。