目的从介观角度研究水在全钒液流电池隔膜中的传质特性.方法采用耗散粒子动力学模拟方法,使用Materials Studio软件构建Nafion膜与水的粗粒化模型,分析了Nafion膜中水通道三维拓扑结构,研究温度、水含量对Nafion膜中水的扩散行为的影响.结果随水含量的增加,全钒液流电池隔膜中的水团簇逐渐形成相互连接且贯穿的海绵状连续水通道、隔膜中磺酸基配位数增加、水在膜中的扩散系数增大;随着温度升高,水在隔膜中的扩散系数增大;在磺酸基周围配位的水分子大部分分布在0.5 nm范围内.结论在一定范围内增加水含量和提高温度有利于Nafion膜中的质子传递,可以提高全钒液流电池的性能.
The mass transfer characteristics of water in the membranes of the Vanadium Redox Flow Battery were studied from mesoscopic perspective.The Nafion membrane and water coarsegrained model were constructed by using the dissipative particle dynamics simulation method in the Materials Studio software.The three-dimensional topological structure of water channels in Nafion membrane was analyzed to study the effect of temperature and water content on the diffusion behavior of water in Nafion membrane.The results showed that,with the increase of water content,the interconnection water channels formed in the proton exchange membrane,the number of sulfonic coordination number of acid groups in the membrane and the diffusion coefficient of water inthe membrane increased.As the temperature rises,the diffusion coefficient of water in the membrane increases.Most of the water molecules coordinated around the sulfonic acid groups are distributed in the range of 0.5 nm.Conclusion is that increasing the water content and the temperature in a certain range are favorable for the proton transfer in the Nafion membrane,and the performance of the vanadium redox flow battery can be improved.