Organic‐Inorganic Coupling Strategy: Clamp Effect to Capture Mg 2+ for Aqueous Magnesium Ion Capacitor

作者：Mudi Li, Yaxi Ding, Siwen Zhang, Minghui Liu, Jiazhuo Li, Ying Sun, Lingfeng Zhu, Hui Li, Zhi Gen Yu, Yong‐Wei Zhang, Hongge Pan, Bosi Yin, Tianyi Ma · 发表于：Angewandte Chemie International Edition · 年份：2024 · DOI：10.1002/anie.202412735 · 被引用次数：19 · 研究领域：Supercapacitor Materials and Fabrication、Layered Double Hydroxides Synthesis and Applications、Ammonia Synthesis and Nitrogen Reduction

Abstract The rapid transport kinetics of divalent magnesium ions are crucial for achieving distinguished performance in aqueous magnesium‐ion battery‐based energy storage capacitors. However, the strong electrostatic interaction between Mg 2+ with double charges and the host material significantly restricts Mg 2+ diffusivity. In this study, a new composite material, EDA‐Mn 2 O 3, with double‐energy storage mechanisms comprising an organic phase (ethylenediamine, EDA) and an inorganic phase (manganese sesquioxide) was successfully synthesized via an organic–inorganic coupling strategy. Inorganic‐phase Mn 2 O 3 serves as a scaffold structure, enabling the stable and reversible intercalation/deintercalation of magnesium ions. The organic phase EDA adsorbed onto the surface of Mn 2 O 3 as an elastic matrix, works synergistically with Mn 2 O 3 , and utilizes bidentate chelating ligands to capture Mg 2+ . The robust coordination effect of terminal biprotonic amine in EDA enhances the structural diversity and specific capacity characteristics of the composite material, as further corroborated by density functional theory (DFT) calculations, ex situ XRD, XPS, and Raman spectroscopy. As expected, the EDA‐Mn 2 O 3 composite achieved an outstanding specific discharge capacity of 188.97 mAh/g at 0.1 A/g. Additionally, an aqueous magnesium ion capacitor with EDA‐Mn 2 O 3 serving as the cathode can reach 110.17 Wh/kg, which stands out among the aqueous magnesium ion capacitors that have be...