Li Mudi, Ding Yaxi, Zhang Siwen, Liu Minghui, Li Jiazhuo, Sun Ying, Zhu Lingfeng, Li Hui, Yu Zhi Gen, Zhang Yong-Wei, Pan Hongge, Yin Bosi, Ma Tianyi
Institute of Clean Energy Chemistry, Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Material, College of Chemistry, Liaoning University, Shenyang, 110036, P. R. China.
Centre for Atomaterials and Nanomanufacturing (CAN), School of Science, RMIT University, Melbourne, VIC 3000, Australia.
Angew Chem Int Ed Engl. 2024 Dec 20;63(52):e202412735. doi: 10.1002/anie.202412735. Epub 2024 Oct 24.
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 with double charges and the host material significantly restricts Mg diffusivity. In this study, a new composite material, EDA-MnO 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 MnO serves as a scaffold structure, enabling the stable and reversible intercalation/deintercalation of magnesium ions. The organic phase EDA adsorbed onto the surface of MnO as an elastic matrix, works synergistically with MnO, and utilizes bidentate chelating ligands to capture Mg. 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-MnO 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-MnO serving as the cathode can reach 110.17 Wh/kg, which stands out among the aqueous magnesium ion capacitors that have been reported thus far. The abundant reversible redox sites are ensured by the strategic design concept based on the synergistic structure and composition advantages of organic and inorganic phases. This study aimed to explore the practical application value of organic-inorganic composite electrodes with double-energy storage mechanisms.
二价镁离子的快速输运动力学对于基于水系镁离子电池的储能电容器实现卓越性能至关重要。然而，双电荷镁离子与主体材料之间强烈的静电相互作用显著限制了镁离子的扩散率。在本研究中，通过有机-无机耦合策略成功合成了一种具有双储能机制的新型复合材料EDA-MnO，其包含有机相（乙二胺，EDA）和无机相（三氧化二锰）。无机相MnO作为骨架结构，能够实现镁离子的稳定且可逆的嵌入/脱嵌。有机相EDA作为弹性基质吸附在MnO表面，与MnO协同作用，并利用双齿螯合配体捕获镁离子。EDA中末端双质子胺的强大配位效应增强了复合材料的结构多样性和比容量特性，密度泛函理论（DFT）计算、非原位XRD、XPS和拉曼光谱进一步证实了这一点。正如预期的那样，EDA-MnO复合材料在0.1 A/g时实现了188.97 mAh/g的出色比放电容量。此外，以EDA-MnO作为正极的水系镁离子电容器可达110.17 Wh/kg，在迄今为止报道的水系镁离子电容器中脱颖而出。基于有机相和无机相的协同结构和组成优势的策略性设计理念确保了丰富的可逆氧化还原位点。本研究旨在探索具有双储能机制的有机-无机复合电极的实际应用价值。
