全钒液流电池中蛇型和插指型流道的对比  

Comparative study between serpentine and interdigitated flow fields for vanadium redox flow batteries

作　　者：王振宇 郭子啸 范新庄 赵天寿[1,2] WANG Zhenyu;GUO Zixiao;FAN Xinzhuang;ZHAO Tianshou(The Hong Kong University of Science and Technology,Hong Kong 999077,China;Southern University of Science and Technology,Shenzhen 518055,Guangdong,China)

机构地区：[1]香港科技大学,中国香港999077 [2]南方科技大学,广东深圳518055

出　　处：《储能科学与技术》2022年第4期1121-1130,共10页Energy Storage Science and Technology

基　　金：深港澳科技计划(No.SGDX2020110309460000);广东省自然科学基金(Grant 2021A1515011821)。

摘　　要：全钒液流电池因具有优异的安全性和超长的循环寿命,使其在规模储能领域具有广阔的应用前景。但钒电池较高的储能成本限制了它的规模化发展,大幅提高其功率密度进而降低储能成本是实现钒电池商业化的有效途径。流场是影响钒电池功率密度的关键部件之一,匹配的流场能够有效改善钒电池在高倍率放电时的浓差极化,从而实现较高的功率密度。但目前关于不同流场性能优劣的研究结论却存在较大分歧,严重影响了它们的工程化应用。本工作针对钒电池中最为常用的蛇型和插指型流道,通过仿真和实验相结合的方式系统地研究了比流量、流场尺寸对传质及电池性能的影响规律,并揭示了这两种流场在不同工况下得出不同甚至相反结论的根本原因。结果显示,在相同比流量下,电解液在蛇型流道电极内的流速远大于插指型流道,所以在低比流量下蛇型流道的性能明显好于插指型流道;增加比流量或提高流场尺寸均可提升电池的性能,由于插指型流道的临界流量大于蛇型流道,所以插指型流道性能的提升幅度明显大于蛇型流道,进而导致两种流场间的性能差异会随着比流量和流场尺寸的增加逐渐减小甚至出现性能反转。本工作不仅加深了对钒电池流场结构及其传质过程的认识,也为流场的工程化应用提供了依据和方向。Because of their excellent safety and long cycle life,all-vanadium redox flow batteries(VRFBs)hold promise for large-scale energy storage;however,the battery's relatively high-cost limits its commercialization.Increasing the power density of VRFBs is an efficient way to reduce the cost.Flow fields are an important factor in determining power density,and well-designed flow fields can effectively reduce the concentration polarization of VRFBs under high rate discharge,increasing the corresponding power density.Serpentine and interdigitated flow fields are the two most commonly used flow fields in VRFBs at the moment.Conclusions about their contributions to battery performance,however,are debatable.In this paper,we theoretically and experimentally investigate the effect of the specific flow rates and flow field size on the mass transfer and battery performance of VRFBs with serpentine and interdigitated flow fields.The results show that under the same specific flow rate,the electrolyte flow velocity in serpentine flow fields is much higher than in interdigitated flow fields,resulting in better battery performance at low specific flow rates for the former.Increasing the flow rates and size of the flow field can significantly improve the battery performance for both flow fields.However,because the critical flow rate of interdigitated flow fields is greater than that of serpentine flow fields,the performance improvement of the former with the increasing specific flow rates and flow field size is significantly greater than that of the latter,and the performance difference between these two flow fields will gradually decrease or even reverse.This work not only advances our understanding of the flow field structure and mass transfer process in VRFBs but also provides evidence and guidance for the engineering application of the flow fields.

关 键 词：全钒液流电池 蛇型流道 插指型流道 比流量 流场尺寸 

分 类 号：TM911[电气工程—电力电子与电力传动]