The vanadium redox flow battery (VRFB) has emerged as a promising technology for large-scale storage of intermittent power generated from renewable energy sources due to its advantages such as scalability, high energy efficiency and low cost. In the current study, a three-dimensional(3D) Lattice Boltzmann model is developed to simulate the transport mechanisms of electrolyte flow, species and charge in the vanadium redox flow battery at the micro pore scale. An electrochemical model using the Butler-Volmer equation is used to provide species and charge coupling at the surface of active electrode. The detailed structure of the carbon paper electrode is obtained using X-ray Computed Tomography(CT). The new model developed in the paper is able to predict the local concentration of different species, over-potential and current density profiles under charge/discharge conditions. The simulated capillary pressure as a function of electrolyte volume fraction for electrolyte wetting process in carbon paper electrode is presented. Different wet surface area of carbon paper electrode correspond to different electrolyte volume fraction in pore space of electrode. The model is then used to investigate the effect of wetting area in carbon paper electrode on the performance of vanadium redox flow battery. It is found that the electrochemical performance of positive half cell is reduced with air bubbles trapped inside the electrode.

钒氧化还原液流电池（VRFB）凭借其可扩展性，高能效和低成本等优点，已成为一种可大规模存储可再生能源产生的间歇性电力的有前途的技术。在当前的研究中，建立了三维（3D）的Lattice Boltzmann模型，以模拟微孔尺度下钒氧化还原液流电池中电解质流，物质和电荷的传输机制。使用Butler-Volmer方程的电化学模型可用于在活性电极表面提供物质和电荷耦合。碳纸电极的详细结构是使用X射线计算机断层扫描（CT）获得的。本文开发的新模型能够预测不同物种的局部浓度，充电/放电条件下的过电势和电流密度曲线。提出了模拟毛细压力与碳纸电极中电解液润湿过程中电解液体积分数的关系。碳纸电极的不同湿表面积对应于电极孔空间中不同的电解质体积分数。然后，该模型用于研究碳纸电极的润湿面积对钒氧化还原液流电池性能的影响。发现正极半电池的电化学性能会因气泡滞留在电极内部而降低。碳纸电极的不同湿表面积对应于电极孔空间中不同的电解质体积分数。然后，使用该模型研究碳纸电极的润湿面积对钒氧化还原液流电池性能的影响。发现正极半电池的电化学性能会因气泡滞留在电极内部而降低。碳纸电极的不同湿表面积对应于电极孔空间中不同的电解质体积分数。然后，该模型用于研究碳纸电极的润湿面积对钒氧化还原液流电池性能的影响。发现正极半电池的电化学性能会因气泡滞留在电极内部而降低。