Competing forces in liquid metal electrodes and batteries
Competing forces in liquid metal electrodes and batteries
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DOI：
10.1016/j.jpowsour.2017.12.042
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发表时间：
2018-02-28
影响因子：
9.2
通讯作者：
Weier, Tom
中科院分区：
文献类型：
--
作者：
Ashour, Rakan F.;Kelley, Douglas H.;Weier, Tom
液态金属电池被提出用于低成本电网规模的能量存储。在它们的操作期间，固体金属间相通常在阴极中形成并且已知限制电池的容量。液体电极中的流体流动可以增强质量传递并减少局部金属间化合物的形成，并且可以通过仔细选择电池电连接的位置和拓扑来促进流体流动。在这方面，我们研究了四种现象，驱动流：瑞利-勒纳尔对流，内部加热对流，电涡流，旋流，在实验和模拟。在实验中，我们使用超声多普勒测速仪（UDV）来测量在160摄氏度的共晶PbBi电极的流量，并受到所有四种现象。在数值模拟中，我们将这些现象隔离开来，并使用OpenFOAM分别进行模拟。通过UDV梁模型的模拟速度与实验比较，我们发现所有这四种现象都可以增强LMB中的传质。我们解释了流动方向，描述了如何相互作用的现象，并提出了无量纲的数字估计它们的相互关联。电气连接的简要讨论总结了我们工作的工程意义。
Liquid metal batteries are proposed for low-cost grid scale energy storage. During their operation, solid inter metallic phases often form in the cathode and are known to limit the capacity of the cell. Fluid flow in the liquid electrodes can enhance mass transfer and reduce the formation of localized intermetallics, and fluid flow can be promoted by careful choice of the locations and topology of a battery's electrical connections. In this context we study four phenomena that drive flow: Rayleigh-Renard convection, internally heated convection, electro-vortex flow, and swirl flow, in both experiment and simulation. In experiments, we use ultrasound Doppler velocimetry (UDV) to measure the flow in a eutectic PbBi electrode at 160 degrees C and subject to all four phenomena. In numerical simulations, we isolate the phenomena and simulate each separately using OpenFOAM. Comparing simulated velocities to experiments via a UDV beam model, we find that all four phenomena can enhance mass transfer in LMBs. We explain the flow direction, describe how the phenomena interact, and propose dimensionless numbers for estimating their mutual relevance. A brief discussion of electrical connections summarizes the engineering implications of our work.