Deng Shenzhen, Tie Zhiwei, Yue Fang, Cao Hongmei, Yao Minjie, Niu Zhiqiang
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center, College of Chemistry, Nankai University, Tianjin, 300071, P. R. China.
Angew Chem Int Ed Engl. 2022 Mar 14;61(12):e202115877. doi: 10.1002/anie.202115877. Epub 2022 Jan 27.
Manganese oxides are promising cathode materials for aqueous zinc-ion batteries (ZIBs) due to their high energy density and low cost. However, in their discharging processes, the Jahn-Teller effect and Mn disproportionation often lead to irreversible structural transformation and Mn dissolution, deteriorating the cycling stability of ZIBs. Herein, ZnMn O quantum dots (ZMO QDs) were introduced into a porous carbon framework by in-situ electrochemically inducing Mn-MIL-100-derived Mn O quantum dots and the carbon composite. In such ZMO QDs and carbon composite, the quantum dot structure endows ZnMn O with a shorter ion diffusion route and more active sites for Zn . The conductive carbon framework is beneficial to the fast transport of electrons. Furthermore, at the interface between the ZMO QDs and the carbon matrix, the Mn-O-C bonds are formed. They can effectively suppress the Jahn-Teller effect and manganese dissolution of discharge products. Therefore, Zn/ZMO QD@C batteries display remarkably enhanced electrochemical performance.
由于具有高能量密度和低成本，锰氧化物是水系锌离子电池（ZIBs）很有前景的阴极材料。然而，在其放电过程中，Jahn-Teller效应和锰歧化反应常常导致不可逆的结构转变和锰溶解，从而降低了ZIBs的循环稳定性。在此，通过原位电化学诱导由Mn-MIL-100衍生的ZnMnO量子点和碳复合材料，将ZnMnO量子点（ZMO QDs）引入到多孔碳框架中。在这种ZMO QDs和碳复合材料中，量子点结构赋予ZnMnO更短的离子扩散路径和更多的锌活性位点。导电碳框架有利于电子的快速传输。此外，在ZMO QDs与碳基体的界面处，形成了Mn-O-C键。它们可以有效抑制放电产物的Jahn-Teller效应和锰溶解。因此，Zn/ZMO QD@C电池展现出显著增强的电化学性能。
