纳米多孔质子传导膜中钒离子和水分子迁移行为研究  

Study on transport behaviors of vanadium ions and water across nano-porous proton-conductive membranes

作　　者：宋士强[1] 陈晓[1] 郭伟男[1] 范永生[1] 王保国[1] 

机构地区：[1]清华大学化学工程系,北京100084

出　　处：《膜科学与技术》2014年第1期9-14,共6页Membrane Science and Technology

基　　金：国家自然科学基金资助项目(21076112;21276134);国家"863"(2012AA051203);"973"计划(2010CB227202)

摘　　要：研究全钒液流电池充电/放电过程,电解液中不同价态水合钒离子、氢离子、水分子在纳米孔径的质子传导膜中的渗透迁移行为,为膜材料性能改进以及电解液系统管理提供依据.通过测定全钒液流电池开路状态下的自放电、恒电流模式下的充电/放电循环过程,分析钒离子渗透和水迁移影响因素,揭示电池运行过程纳米多孔质子传导膜中钒离子渗透及水迁移规律.结果表明:自放电过程主要发生钒离子浓度差作为推动力的传质扩散,水分子的跨膜净迁移量可忽略;在恒流模式下的充电/放电循环过程中,隔膜两侧阴极、阳极电解液中水合离子迁移、浓差扩散、渗透压效应均发生作用,导致阳极侧电解液向阴极侧发生净的水迁移,需要通过电解液管理保持电池系统正常运行.Transport behaviors of different valence state hydrated vanadium ions, hydronium ion and water across nano-porous proton-conductive membranes were studied during charge/discharge cycles in all- vanadium redox flow battery, thus results contribute a basis for membranes materials optimization and battery electrolyte system management. By testing the processes of static self-discharge and constant current charge/discharge cycles, the factors influencing vanadium ions penetration and water transport through membranes were analyzed in details. The results revealed the transport discipline of vanadium ions and water penetrating through nano-porous proton-conductive membranes in vanadium redox flow battery. During self-discharge process, the mass transport and diffusion is mainly caused by vanadium ions concentration difference, while the net water migration across membrane can be ignored. In constant current charge/discharge cycles, the hydrated ions migration, concentration difference diffusion and osmotic pressure bring influence upon both negative and positive electrolytes crossover membranes simultaneously, which leads to the net water transport from positive electrolyte to negative electrolyte. Electrolyte management needs taking to keep VRB charge/discharge normal performance.

关 键 词：全钒液流电池 纳米多孔质子传导膜 钒离子渗透 水迁移 

分 类 号：TQ028[化学工程]