Sodium ion capacitors (SICs) are promising candidates in energy storage for their remarkable power and energy density. However, the inherent disparity in dynamic behavior between the sluggish battery-type anodes and the rapid capacitor-type cathodes constrained their performance. To address this, we fabricated a hollow porous Co_0.85Se/ZnSe@MXene anode featuring multiheterostructure, utilizing facile etching and electrostatic self-assembly strategies. The hollow porous structure and multiple heterointerfaces stabilize the anode by mitigating the volume changes. Density functional theory (DFT) calculations further revealed that induced multilevel built-in electric fields facilitate the formation of rapid ion diffusion pathways and reduce the Na⁺ adsorption energy, thereby boosting Na⁺/electron transport kinetics. The fabricated TA-Co_0.85Se/ZnSe@MXene anode demonstrates outstanding long-term cycling stability of 406 mA h g^–1 after 1000 cycles at 1 A g^–1, with an ultrahigh rate performance of 288 mA h g^–1 at 10 A g^–1. When paired with the active carbon (AC) cathode, the SICs deliver extraordinary energy/power densities of 144 W h kg^–1 and 12000 W kg^–1, maintaining over 80% capacity retention at 1 A g^–1 after 10000 cycles. This innovative strategy of engineering multiheterostructured anode with the induced multilevel built-in electric fields holds significant promise for advancing high-energy and high-power energy storage systems.

中文翻译：

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用于高性能钠离子电容器的具有多电平内置电场的空心多孔 Co0.85Se/ZnSe@MXene 阳极


钠离子电容器 （SIC） 因其卓越的功率和能量密度而成为储能领域的有前途的候选者。然而，缓慢的电池型阳极和快速电容器型阴极之间固有的动态行为差异限制了它们的性能。为了解决这个问题，我们利用简单的蚀刻和静电自组装策略，制造了一种具有多异质结构的空心多孔 Co_0.85Se/ZnSe@MXene 阳极。空心多孔结构和多个异质界面通过减轻体积变化来稳定阳极。密度泛函理论 （DFT） 计算进一步表明，感应多能级内置电场有助于形成快速离子扩散途径并降低 Na⁺ 吸附能，从而促进 Na⁺/电子传递动力学。制造的 TA-Co_0.85Se/ZnSe@MXene 阳极在 1 A g^–1 下循环 1000 次后表现出出色的长期循环稳定性，为 406 mA h g^–1，在 10 A g^–1 下具有 288 mA h g^–1 的超高倍率性能。当与活性炭 （AC） 阴极配对时，SIC 可提供 144 W h kg^–1 和 12000 W kg^–1 的非凡能量/功率密度，在 10000 次循环后在 1 A g^–1 下保持超过 80% 的容量保持。这种具有感应多级内置电场的多异质结构阳极工程创新策略为推进高能和高功率储能系统具有重要前景。