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

[1]Rychcik M, Skyllas-Kazacos M. Characteristics of a new all vanadium redox flow battery[J].J Power Sources,1988,22(1):59-67.
[2]Skyllas-Kazacos M, Kazacos M. State of charge monitoring methods for vanadium redox flow battery control[J].J Power Sources,2011,196:8 822-8 827.
[3]Weber A Z，Mench M M，Meyers J P，et al. Redox flow batteries:a review[J].J Appl Electrochem，2011,41：1 137-1 164.
[4]Tang B, Yan C W, Wang F H. Modification and evaluation of membrane for vanadium redox battery applications[J].J Appl Electrochem,2004,34:1 205-1 210.
[5]青格乐图,郭伟男,范永生，等. 全钒液流电池用质子传导膜研究进展[J].化工学报,2013,64(2):427-435.
[6]刘平,青格乐图,郭伟男，等.质子传导膜制备方法放大与膜性能表征[J].膜科学与技术,2012,32(2):24-29.
[7]Mohammadi T, Chieng S C, Skyllas-Kazacos M. Water transport study across commercial ion exchange membranes in the vanadium redox flow battery[J].J Membr Sci,1997,133:151-159.
[8]Sukkar T, Skyllas-Kazacos M. Water transfer behavior across cation exchange membranes in the vanadium redox battery[J].J Membr Sci,2003,222:235-247.
[9]Sun C X, Chen J, Zhang H M, et al. Investigations on transfer of water and vanadium ions across Nafion membrane in an operating vanadium redox flow battery[J].J Power Sources,2010,195:890-897.
[10]赵永涛,席靖宇,滕祥国，等. 钒电池电解液体积变化规律研究[J].化学学报,2011,69(2):132-136.
[11]青格乐图, 宋士强, 范永生，等. 质子传导膜内受限空间离子扩散过程[J].化工学报,2013,64(2):689-695.
[12]范永生，陈晓，王保国. 基于交流阻抗法的离子交换膜电阻研究[J]. 膜科学与技术，2011，31(2):14-18.
[13]刘素琴,桑玉,李林德，等.电位滴定法测定钒电池电解液中不同价态的钒[J].理化检验，2007,43(12):1 077-1 080.
[14]王保国,宋士强,刘云，等.一种液流电池电解液在线取样装置[P].中国,发明专利授权号:CN102721578A.2012-10-10.
[15]王保国,刘云,陈晓，等.一种密封状态下分析电解液浓度的装置[P].中国,发明专利授权号:CN102735795A.2012-10-17.
[16]You Dongjiang,Zhang Huaming,Sun Chenxi,et al.Simulation of the self-discharge process in vanadium redox flow battery[J].J Power Sources,2011,196:1578-1585.
[17]陈金庆, 朱顺泉, 王保国，等. 全钒液流电池开路电压模型[J].化工学报,2009,60(1)：211-215.
[18]Zawodzinski T A, Derouin C, Radzinski S, et al. Water uptake by and transport through Nafion 117 membranes[J].J Electrochem Soc,1993,140:1 041-1 047.
[19]Vijayakumar M, Li L, Nie Z, et al. Structure and stability of hexa-aqua V(Ⅲ) cations in vanadium redox flow battery electrolytes[J].J Physical Chemistry Chemical Physics,2012,14:10 233-10 242.
[20]Grant C V, Cope W, Ball J A, et al. Electronic structure of the aqueous vanadyl ion probed by 9 and 94 GHz EPR and pulsed ENDOR spectroscopies and density functional theory calculations[J].J Phys Chem B,1999,103(48):10 627-10 631.