| Large-scale development of renewable energy storage system has become our research object.Iodine-zinc REDOX flow cells are considered as a promising electrochemical energy storage system due to their high energy density,high safety and low cost,which can balance the uneven distribution of renewable energy sources such as wind and solar energy over time and space.At present,there is no large-scale research team in China on iodine-zinc liquid flow battery,so it is in the experimental stage.In this paper,the electrochemical model and circuit model of iodine-zinc liquid flow battery are established.The two are related to the influence of ion concentration on the energy of the battery.Considering the flow of electrolyte,a fluid model is established.In order to reduce this consumption,the flow channel is optimized.The specific research contents of this paper are as follows:Firstly,the reaction principle and electrochemical model of iodine-zinc liquid flow cell were studied.The reaction mechanism is described in detail.The REDOX reaction of the electrolyte has a crucial impact on the overall efficiency of the battery.The electrochemical model of the battery is composed of chemical reaction equation,charge state expression and energy loss equation.The electrochemical model laid a solid foundation for the subsequent modeling work.Then the influence of electrochemical reaction,circuit change and electrolyte flow on the working state of iodine-zinc liquid flow battery was studied.The electrochemical model,equivalent circuit model and fluid mechanics model were used to build the battery simulation model using Matlab/Simulink module.The model describes the basic characteristics of the battery well.Then,in order to improve the uniform distribution of electrolyte in the bipolar plate flow channel of the iodium-zinc liquid flow battery and further improve the actual working characteristics of the battery,computational fluid dynamics was used to analyze the bipolar plate flow field by considering the inlet and outlet direction,increasing the number of inclined baffle and channels.The numerical simulation results show that compared with the traditional flow channel,the multi-channel serpentine pipe with different sides of double baffles can not only improve the uniform characteristics of fluid parameter distribution,but also effectively reduce the flow resistance and energy consumption of the pump.The evenly distributed electrolyte can increase the energy utilization rate of iodine-zinc liquid flow battery and effectively improve the battery operation efficiency.Finally,according to the working principle and reaction mechanism of iodine-zinc liquid flow battery,the single cell stack and positive and negative electrode electrolyte suitable for laboratory were prepared.According to the national standard for battery test,the experimental scheme is designed.The charge-discharge characteristic curve of the battery was obtained through the experimental data information and processing.The influence of each parameter on the SOC of the liquid flow battery was compared and analyzed by analyzing the changing trend of the graph. |
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