Most reported cathode materials for rechargeable aqueous Al metal batteries are based on an intercalative-type chemistry mechanism. Herein, iodine embedded in MOF-derived N-doped microporous carbon polyhedrons (I₂@ZIF-8-C) is proposed to be a conversion-type cathode material for aqueous aluminum-ion batteries based on “water-in-salt” electrolytes. Compared with the conventional Al–I₂ battery using ionic liquid electrolyte, the proposed aqueous Al–I₂ battery delivers much enhanced electrochemical performance in terms of specific capacity and voltage plateaus. Benefitting from the confined liquid–solid conversion of iodine in hierarchical N-doped microporous carbon polyhedrons and enhanced reaction kinetics of aqueous electrolytes, the I₂@ZIF-8-C electrode delivers high reversibility, superior specific capacity (≈219.8 mAh g⁻¹ at 2 A g⁻¹), and high rate performance (≈102.6 mAh g⁻¹ at 8 A g⁻¹). The reversible reaction between I₂ and I⁻, with I₃⁻ and I₅⁻ as intermediates, is confirmed via ex situ Raman spectra and X-ray photoelectron spectroscopy. Furthermore, solid-state hydrogel electrolyte is employed to fabricate a flexible Al–I₂ battery, which shows performance comparable to batteries using liquid electrolyte and can be integrated to power wearable devices as a reliable energy supply.

中文翻译：

---

受限碘转化化学实现的高倍率水性铝离子电池

大多数报道的用于可充电水性铝金属电池的正极材料都是基于嵌入型化学机制。在此，嵌入 MOF 衍生的 N 掺杂微孔碳多面体（I ₂ @ZIF-8-C）中的碘被提议作为基于“盐包水”电解质的水性铝离子电池的转换型正极材料. 与使用离子液体电解质的传统 Al-I ₂电池相比，所提出的水性 Al-I ₂电池在比容量和电压平台方面提供了大大增强的电化学性能。受益于分级 N 掺杂微孔碳多面体中碘的受限液固转化和增强的水性电解质反应动力学，I ₂@ZIF-8-C 电极具有高可逆性、优异的比容量（≈219.8 mAh g ^-1在 2 A g ^-1）和高倍率性能（≈102.6 mAh g ^-1在 8 A g ^-1）。I ₂和I ^-之间的可逆反应，以I ₃ ^-和I ₅ ^-作为中间体，通过非原位拉曼光谱和X射线光电子能谱证实。此外，固态水凝胶电解质用于制造柔性 Al-I ₂电池，其性能可与使用液体电解质的电池相媲美，并且可以集成到可穿戴设备中作为可靠的能源供应。