Zinc-ion capacitors (ZICs) have attracted great attention due to a series of advantages. However, the cathode materials are still the bottleneck for high-performance ZICs to be achieved. Therefore, ZIF-8-derived porous carbons are one of the most promising candidates but ZIF-8 nanoparticles with different sizes exhibited various electrochemical performances in ZICs. Herein, a series of monodispersed ZIF-8 nanoparticles are first prepared by a temperature-controlled process to fabricate the corresponding ZIF-8-based porous carbon nanoparticles with pre-designed sizes. The as-prepared materials have been tested as cathode materials in ZICs. Thus, their size effect allowed us to disclose its correlation with other factors such as ion transport/storage and capacitance. The results reveal that the optimal-sized porous carbon particles can effectively shorten the ion transport distance and accelerate the ion diffusion rate, resulting in lower electrical resistance, larger ion diffusion coefficients, and faster electron transport. The presented findings can facilitate the design of new advanced cathode materials paving the way for the development of high-performance cathode materials for ZICs in the future.

中文翻译：

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ZIF-8 衍生的正极材料对锌离子电容器性能的尺寸依赖性影响


锌离子电容器 （ZIC） 因其一系列优点而受到广泛关注。然而，正极材料仍然是实现高性能 ZIC 的瓶颈。因此，ZIF-8 衍生的多孔碳是最有前途的候选者之一，但不同尺寸的 ZIF-8 纳米颗粒在 ZICs 中表现出不同的电化学性能。在此，首先通过温控工艺制备了一系列单分散的 ZIF-8 纳米颗粒，以制备相应的具有预先设计尺寸的基于 ZIF-8 的多孔碳纳米颗粒。制备的材料已在 ZIC 中作为正极材料进行了测试。因此，它们的尺寸效应使我们能够揭示它与其他因素（如离子传输/存储和电容）的相关性。结果表明，最佳尺寸的多孔碳颗粒可以有效缩短离子传输距离并加快离子扩散速率，从而降低电阻、提高离子扩散系数和加快电子传输速度。所提出的研究结果可以促进新的先进正极材料的设计，为未来 ZIC 的高性能正极材料的开发铺平道路。