钒液流电池电解液的热力学研究进展

Development of electrolyte thermodynamic studies for vanadium flow battery

钒液流电池作为可以规模化储能的一种二次电池越来越受到人们的重视,和其它类型的化学电池不同,其电解液不仅是离子导体,也是实现能量存储的电活性物质,是钒电池的核心。为了提高钒电池储能系统的性能并使之稳定运行,必须深刻认识钒电解液的热力学性质及变化规律。溶液热力学的研究可以提供如离子的存在形式、离子的活度及活度系数、不同形式离子对的解离常数等信息。这些热力学基础数据在设计电池和提升其性能方面都有着重要意义。本文对钒液流电池电解液热力学性质的研究进行了综述,重点介绍了量热法、密度法、电导法等在钒溶液研究中的应用,还介绍了Pitzer电解质溶液理论应用于钒溶液的研究情况,最后对热力学在钒液流电池电解液研究中的应用前景进行展望。

Vanadium flow battery is being attracted more and more attentions because it can be used for large-scale electrical energy storage. Different from other types of secondary batteries, the electrolyte of vanadium flow battery （VLB） is not only the ion conductor, but also serves as the electrochemical active substances for storing energy. In order to make the batteries more stable and more efficient, it is indispensable to understand thermodynamic properties of the electrolyte. The thermodynamics of vanadium solution can provide us useful information including the ion existing form in the solution, activity of vanadium ions and their disassociation constants etc. In this review, we will summarize the recent development of thermodynamic studies of vanadium flow batteries including experimental methods such as calorimetry, densimetry and conductivity methods. The Pitzer＇s theory is also introduced to describe the vanadium electrolyte. Besides, the future work on thermodynamic studies for vanadium flow battery has been put forward.