Starodubtseva Alena A, Zhigalenok Yaroslav S, Maldybaev Kairgali M, Galeyeva Alina K, Trussov Ivan A, Kurbatov Andrey P
Center of Phisico-Chemical Methods of Research and Analysis, Al-Farabi Kazakh National University Almaty 010000 Kazakhstan
Skoltech Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology Moscow 121205 Russian Federation.
RSC Adv. 2023 Feb 7;13(8):4880-4889. doi: 10.1039/d3ra00040k. eCollection 2023 Feb 6.
Metal-organic compounds (MOFs) are a class of substances composed of metal ions or clusters coordinated to organic ligands to form one-, two-, or three-dimensional structures. Due to their high porosity, excellent adsorption and catalytic activity, as well as the possibility of simultaneous implementation of various charge accumulation mechanisms, they can be used as electrode materials for metal-ion batteries. However, a significant disadvantage is that most MOFs have a low electrical conductivity, and the production of conductive MOFs is a costly, time-consuming and technically difficult process. In this work, we developed a method for synthesizing the Zn(EDTA)(HO) MOF composite and studied the possibility of using it as an anode material for sodium-ion batteries based on aqueous electrolytes. The structure and morphology of the compound was studied using XRD, IR, TGA and SEM. Using cyclic voltammetry, the electrochemical characteristics of the organometallic framework in alkaline electrolytes 1, 10 M NaOH, as well as in saturated aqueous electrolyte NaClO, were evaluated. It has been established that the studied compound does not give a satisfactory electrochemical response in aqueous electrolytes (both in alkaline and neutral media) due to the strong degradation of the electrode material, which is associated with the high solubility of this MOF representative. Cyclic voltammetric studies showed the presence of two redox processes due to the release of metallic zinc from an electrolyte solution, where two forms of zinc exist in equilibrium (the ZnEDTA complex and the free zinc cation). Therefore, we concluded, it is not possible to use this material as an anode for water-based sodium-ion batteries in contrary to a published research study.
金属有机化合物（MOFs）是一类由金属离子或簇与有机配体配位形成一维、二维或三维结构的物质。由于它们具有高孔隙率、优异的吸附和催化活性，以及同时实现各种电荷积累机制的可能性，它们可用作金属离子电池的电极材料。然而，一个显著的缺点是大多数MOFs的电导率较低，并且制备导电MOFs是一个成本高、耗时且技术难度大的过程。在这项工作中，我们开发了一种合成Zn(EDTA)(HO) MOF复合材料的方法，并研究了将其用作基于水性电解质的钠离子电池负极材料的可能性。使用XRD、IR、TGA和SEM研究了该化合物的结构和形态。使用循环伏安法评估了有机金属骨架在碱性电解质1、10 M NaOH以及饱和水性电解质NaClO中的电化学特性。已经确定，由于电极材料的强烈降解，所研究的化合物在水性电解质（碱性和中性介质中）中均未给出令人满意的电化学响应，这与该MOF代表物的高溶解度有关。循环伏安研究表明，由于电解质溶液中金属锌的释放，存在两个氧化还原过程，其中两种形式的锌处于平衡状态（ZnEDTA络合物和游离锌阳离子）。因此，我们得出结论，与已发表的研究相反，不可能将这种材料用作水性钠离子电池的负极。
