Research On Energy And Mass Transter Transformation And Performance Optimization Of All-vanadium Flow Batteries

In the current era of great changes in the energy industry,achieving carbon peak by 2030 and carbon neutrality by 2060 is not only the strategic guidance of China’s development,but also the strategic goal of global green energy development.In order to solve the problem of random fluctuation of renewable energy,energy storage technology has become an indispensable part of the construction of new energy power system.How to develop a more safe and efficient energy storage mode is also the current research hotspot.Due to its features of free site selection,high efficiency,long life and high safety,all-vanadium flow batteries are widely used in the field of large-scale energy storage.However,the lack of understanding of the energy and mass transfer and transformation mechanism and the cooperative control mechanism of multi-physical fields in batteries hinders the further development of their technical application.In this paper,starting from the optimization of battery performance,a mathematical and physical model of the coupling between the internal electrochemical reaction and the heat and mass transfer process of a new radial flow all-vanadium flow battery unit was established through numerical simulation.The influence of battery structure and operating parameters on the distribution of the internal physical fields and performance parameters of the battery was studied.The optimization and control measures of battery performance were explored.Firstly,a mathematical physical model of the coupling of heat and mass transfer and electrochemical reaction in a vanadium flow cell under the action of multiple physical fields was established.Secondly,the traditional battery structure was optimized by numerical simulation method,and the influences of parameters such as the number of electrolyte inlet,electrode thickness,flow field structure and initial concentration of electrolyte were studied under the new radial flow all-vanadium flow battery structure.Finally,the variation rules of the internal velocity distribution,ion concentration distribution,pressure distribution,electrode overpotential,electrode potential,energy efficiency and other performance parameters were obtained.The results show that with the increase of the number of electrolyte inlet,the distribution uniformity of electrolyte concentration field increases gradually,and the potential increases.When the electrode thickness increases,the ion concentration decreases and the potential decreases.With the increase of channel depth,the concentration of active ions increases and the potential decreases.Higher electrolyte concentration shows better performance,and the changes of electrolyte flow and current density have many influences on the battery.The battery performance can be further improved by adjusting the mass transfer process and energy efficiency changes in many aspects.Through the research and analysis of the subject,the differences in battery performance under different working conditions were compared,and the optimization design of vanadium flow battery was provided with reference from the structural changes and the influence of performance parameters.