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Исследование концепции использования жидких электро-активных материалов в проточных батареяхдипломная работа (Магистр)
- Научные руководители: Трошин Павел Анатольевич, Новиков Валентин Владимирович
- Автор: Володин Иван
- Тип: Магистр
- Организация, в которой проходила защита: Институт элементоорганических соединений им. А.Н. Несмеянова РАН, Сколковский институт науки и технология
- Год защиты: 2019
- Аннотация: Redox Flow Battery (RFB) is a technology for energy storage. Electrochemical nature of processes in RFB allows to work with very small time of respond (in the range of milliseconds) and design aspects allows to regulate capacity and power of the system independently one from another. What is more, RFBs have long cycle life, more than 13 000 cycles of stable work. The technology has high power, it is flexible, stable and comparably cheap, its potential is clear and huge, but still there are drawbacks. One of the main deficiencies is, that despite the fact that technologies for electrochemical energy storage has the highest energy density, still RFB has the lowest specific capacity among them and this is an obstacle for commercialization of the battery. The aim of this work is to increase the energy density of RFBs. For operation, RFB needs electrolytes in liquid phase. Usually the specific capacity is restricted by solubility of active substance in electrolyte but if electroactive substance will be in a liquid form from the beginning, the battery can work without a solvent. Usually solvent content in electrolyte is 50% or even more, and getting rid of it can lead to increase in capacity by a factor of 2 or even more! In this work a concept of organic liquid electroactive materials was closely investigated. A “home-made” laboratory RFB prototype was designed and fabricated. Multiple organic redox active substances, namely pyrazines, benzoxazoles, benzothiazole, p-thiophenol, quinoxaline, 1,2,4,5-tetrazine derivative, 2,1,3-benzothiadiazole, 2,1,3-benzoxadiazole and its derivative, phenothiazine derivative, and various triphenylamine derivatives with low melting temperature were tested for electrochemical activity and stability using cycling voltammetry technique. Four triphenylamine derivatives were chosen as the most stable ones, their diffusion coefficients were revealed by rotation disk electrode measurements and were compared with widely known in RFB area substance, TEMPOL organic molecule; rate constants were measured by impedance method and compared with Ferrocene kinetics, estimated in same solutions. Two of four investigated substances were liquids at room temperature and, having fastest diffusion and kinetics, were chosen to be cycled in laboratory RFB prototype. M4 molecule has shown stable electroactive behavior at 56% battery state of charge (SOC) for 50 cycles at 0.5 𝑚𝐴⁄𝑐𝑚2 current density. Additionally, M4 has one of highest diffusion constants and fastest rate constant among studiedmaterials:8.65∙10./ 𝑐𝑚0⁄𝑠and1.14∙10.3 𝑐𝑚⁄𝑠respectively;andoneofthehighest 7 redox potentials: 0.91 V vs. SHE. The substance has high density of 1.56 𝑔⁄𝑐𝑚 , and in cope with such characteristics as liquid nature, fast diffusion and kinetics, high stability and strongly cathodic redox potential, M4 has big chances of application as cathodic molecule for Redox Flow Batteries based on liquid organic electroactive materials.
- Добавил в систему: Новиков Валентин Владимирович