中文摘要：

目的深入研究电极的传质机理,提高全钒液流电池的性能.方法采用Materials Studio软件构建包含碳纳米管（CNT）、水、V^（2＋）、V^（3＋）、SO_4^（2-）的介观模型,应用粗粒化分子动力学模拟方法对负极反应时电解液中各种粒子的传递特性进行介观分析.在Martini力场作用下,研究温度、碳纳米管长度、碳纳米管浓度对水、V^（2＋）、V^（3＋）、SO_4^（2-）的分布有序性和扩散系数的影响.结果随着温度的升高,粒子的扩散系数增大;随着碳纳米管长度的增加或碳纳米管浓度的增加,粒子的扩散系数减小.V^（2＋）的扩散系数为2.54×10^（-6）～8.23×10^（-6）cm^2/s,V^（3＋）的扩散系数为2.51×10^（-6）～5.26×10^（-6）cm^2/s.结论控制温度、碳纳米管长度、碳纳米管浓度获得了优化的扩散速率,减小了因为传质导致的浓差极化问题,提升了全钒液流电池的整体性能.

英文摘要：

The mass transfer characteristics of electrode have an important influence on the performance of the all vanadium flow battery（ VRB）. In order to study the mass transfer mechanism of electrode and improve the performance of the all vanadium flow battery,Materials Studio software was used to build a mesoscopic model consisting of carbon nanotubes（ CNT）,water,V^（2＋）,V^（3＋） and SO_4^（2-）. Based on the coarse-grained molecular dynamics simulation method, the mass transfer characteristics of all particles in electrolyte were analyzed during the negative reaction process.The influence of temperature,carbon nanotube length and carbon nanotube concentration on the distribution and diffusion of water,V^（2＋）,V^（3＋） and SO_4^（2-） were investigated under the Martini force field. The results show that the diffusion coefficient of the particles increases with the increase of temperature,and the diffusion coefficients of each particle show a decreasing trend with the increase of carbon nanotubes length or carbon nanotubes concentration. The obtained diffusion coefficient of V^（2＋） was in the range of 2. 54 × 10^（-6） cm^2·s-1 to 8. 23 × 10^（-6） cm^2·s-1,while the diffusion coefficient of V^（3＋） was in the range of 2. 51 × 10^（-6） cm^2·s-1 to 5. 26 × 10^（-6） cm^2·s-1. By controlling the temperature,carbon nanotube length and concentration of carbon nanotubes,diffusion rate can be optimized, so as to reduce the concentration polarization problem caused by the mass transfer,and improve the whole performance full of all vanadium flow batteries.