Stack reliability is of great importance in commercialization of vanadium redox flow battery (VFB) since practical VFB stacks are prone to undergo material failure and electrolyte leakage caused by unreliable stack design and improper assembling conditions. A comprehensive evaluation of mechanical behavior and analysis of stack failure is thus highly valued for material fabrication, stack design and assembly. In this study, mechanical behavior and Weibull statistics based failure analysis of the VFB stacks are investigated. The Weibull parameters of two key components are firstly determined from tensile strength tests, which, in combination with finite element analysis of the stack mechanical behavior, are subsequently used to calculate the stack failure probability at specified clamping forces for two different stack designs that both contains 20 individual cells. The results demonstrate that the stack failure probability can be significantly reduced by properly decreasing the clamping forces for both designs, while adding a thick plate to the middle of the stack can effectively lower the probability of failure thus offering a superior stack mechanical performance and a prolonged stack life cycle. Such an approach to analyze stack failure can be readily accessed by flow battery engineers for design and assembly of commercial VFB stacks.

电池组可靠性在钒氧化还原液流电池（VFB）的商业化中非常重要，因为实际的VFB电池组容易因不可靠的电池组设计和不正确的组装条件而发生材料故障和电解液泄漏。因此，对于材料制造，堆叠设计和组装，机械性能的综合评估和堆叠故障的分析非常重要。在这项研究中，研究了基于机械行为和威布尔统计量的VFB堆栈的失效分析。首先通过拉伸强度测试确定两个关键部件的Weibull参数，然后结合烟囱机械性能的有限元分析，随后用于计算两个包含20个单独单元的不同堆叠设计在指定夹紧力下的堆叠失效概率。结果表明，通过适当降低两种设计的夹紧力，可以显着降低堆垛失败的可能性，而在堆垛的中间增加一块厚板可以有效地降低失败的可能性，从而提供优异的堆垛机械性能并延长堆垛时间。堆栈生命周期。液流电池工程师可以很容易地使用这种分析电池组故障的方法来设计和组装商用VFB电池组。同时在堆垛的中部增加一块厚板可以有效降低发生故障的可能性，从而提供出色的堆垛机械性能和延长的堆垛寿命周期。液流电池工程师可以很容易地使用这种分析电池组故障的方法来设计和组装商用VFB电池组。同时在堆垛的中部增加一块厚板可以有效降低发生故障的可能性，从而提供出色的堆垛机械性能和延长的堆垛寿命周期。液流电池工程师可以很容易地使用这种分析电池组故障的方法来设计和组装商用VFB电池组。