Low ionic diffusivity, sluggish charge transfer kinetics, and volume shrinkage/expansion during charging/discharging of transition metal oxides and conductive carrier materials seriously reduce capacity and damage cycle stability of electrodes. Herein, we demonstrate an in situ structural transformation strategy for fabricating hierarchical aerogels with hollow Co₃O₄ (H-Co₃O₄) nanoparticles embedded in multi-channel carbon nanofibers (MCNFs) by electrospinning polyacrylonitrile/polystyrene/metal organic framework mixtures, freeze-drying, carbonization and oxidation. The positive electrode prepared with MCNF@H-Co₃O₄ aerogel as the active material exhibits high specific capacity of 244.5 mA h g⁻¹ (1600.6 F g⁻¹) at 1 A g⁻¹, and ultra-long cycle life of retaining 90.5 % of its initial specific capacity after 30,000 cycles at 20 A g⁻¹. Furthermore, N and O co-doped hollow MCNF (NO-HMCNF) aerogels with hollow carbon vesicles embedded in the MCNFs are also prepared by acid-etching. The negative electrode prepared with the NO-HMCNF aerogel as the active material exhibits a high specific capacitance of 362.5 F g⁻¹ at 0.3 A g⁻¹, and retains 95.5 % of its initial specific capacitance after 30,000 cycles at 5 A g⁻¹. The assembled MCNF@H-Co₃O₄//NO-HMCNF asymmetric supercapacitor provides a high energy density of 51.9 W h kg⁻¹ (750.3 W kg⁻¹) and retains 90.1 % of its initial specific capacity after 5000 cycles at 5 A g⁻¹. The “double-void” structure plays crucial roles in exposing active sites and accommodating volume changes for enhancing capacity and cycling of the electrodes.

过渡金属氧化物和导电载体材料的低离子扩散率、缓慢的电荷转移动力学以及充放电过程中的体积收缩/膨胀严重降低了电极的容量并破坏了循环稳定性。在此，我们展示了一种原位结构转换策略，用于通过静电纺丝聚丙烯腈/聚苯乙烯/金属有机框架混合物制备具有嵌入多通道碳纳米纤维 (MCNF) 中的空心 Co ₃ O ₄ (H-Co ₃ O ₄ ) 纳米粒子的分级气凝胶，冷冻干燥、碳化和氧化。_{MCNF@H-Co 3} O ₄制备的正极气凝胶作为活性材料在 1 A g ^-1下表现出 244.5 mAh g ^-1 (1600.6 F g ^-1 ) 的高比容量，以及在 20 A 下 30,000 次循环后保持其初始比容量 90.5% 的超长循环寿命g ^-1。此外，还通过酸蚀刻制备了 N 和 O 共掺杂的中空 MCNF（NO-HMCNF）气凝胶，其中空心碳囊泡嵌入 MCNF 中。以 NO-HMCNF 气凝胶为活性材料制备的负极在 0.3 A g ^{-1下表现出 362.5 F g -1的高比电容，在 5 A g -1}下循环 30,000 次后仍保持其初始比电容的 95.5% . 组装好的 MCNF@H-Co ₃ O₄ //NO-HMCNF非对称超级电容器提供51.9 W h kg ^-1 (750.3 W kg ^{-1 )的高能量密度，并在5 A g -1} 5000次循环后保持其初始比容量的90.1% 。“双空隙”结构在暴露活性位点和适应体积变化以提高电极容量和循环方面起着至关重要的作用。