Modelling of mass transfer and electrode kinetics in liquid metal batteries

液态金属电池中的传质和电极动力学建模

• 批准号: 338560565
• 负责人: Dr.-Ing. Norbert Weber
• 金额: --
• 依托单位: Helmholtz-Zentrum Dresden-Rossendorf (HZDR)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/338560565?language=en
• 关键词: Modelling; mass; transfer; electrode; kinetics

In frame of the German energy transition, 80% of all electricity shall be generated by renewable sources by the year 2050. Due to the fluctuating nature of wind and solar energy, the deployment of stationary energy storage will then become mandatory on a large scale. Such storage devices will have to fulfil a number of crucial requirements: low price (10ct/kWh), long life-time (7000 cycles), high efficiency (>80%) and for short-time storage: fast reaction times. Up to now, no technology fulfils all mentioned criteria; therefore, a development of new, or an improvement of existing storage devices will be necessary.A totally new, and very promising storage technology is the liquid metal battery (LMB) - built as a stable density stratification of two liquid metals, separated by a likewise liquid salt. Cheap raw materials, as Na or Pb and a simple construction allow for building very cheap cells. The completely liquid interior avoids micro-degradation and promises very long life-time. The optimal kinetics at the liquid interfaces allow for potentially very high current densities. These allow providing high power; however, the potentially possible current densities are not always achieved in practice.Objective of this project is an increase of current density and efficiency of LMBs. For this purpose, an electrochemical cell model shall be developed and coupled with an existing fluid dynamics model. It will be implemented in the open source CFD library OpenFOAM, also to simplify its use by other researchers. Later, an analytical and experimental validation is planned. In a first step the influence of different overvoltages (resistances as Ohmic losses, concentration polarisation, charge transfer) shall be evaluated. Subsequently, their dependence on temperature, current density, operation condition and geometry of the cell shall be explored. Finally, it is planned to analyse, how efficiency and current density can be increased by an artificial flow in the cathode. Such a mixing of the liquid interior was proposed several times for an improvement of mass transfer.The significance of the mentioned overvoltages was emphasised several times in the literature; however, their influence was never studied detailed or quantitatively, up to now. By coupling electrodynamics, fluid dynamics and electrochemistry, the model shall be the basis for a detailed simulation of LMBs. In the future it can be easily complemented, e.g. by a model for intermetallic phases, in order to study other processes in the cells.

在德国能源转型的框架内，到2050年，80%的电力将由可再生能源产生。由于风能和太阳能的波动性，固定储能的部署将成为大规模的强制性措施。这种存储设备必须满足许多关键要求：低价格（10 ct/kWh），长寿命（7000次循环），高效率（>80%）以及短时间存储：快速反应时间。到目前为止，还没有一种技术能够满足所有上述标准;因此，开发新的或改进现有的存储设备将是必要的。一种全新的、非常有前途的存储技术是液态金属电池（LMB）--由两种液态金属组成的稳定密度分层结构，由同样的液态盐分隔。廉价的原材料，如钠或铅和简单的结构允许建造非常便宜的电池。完全液体的内部避免了微降解，并保证了很长的使用寿命。液体界面处的最佳动力学允许潜在地非常高的电流密度。这些允许提供高功率;然而，潜在的可能的电流密度并不总是在实践中实现。本项目的目标是提高LMB的电流密度和效率。为此，应开发一个电化学电池模型，并与现有的流体动力学模型相结合。它将在开源CFD库OpenFOAM中实现，也可以简化其他研究人员的使用。随后，计划进行分析和实验验证。在第一步中，应评估不同过电压（电阻，如欧姆损耗、浓度极化、电荷转移）的影响。随后，将探索它们对温度、电流密度、操作条件和电解槽几何形状的依赖性。最后，计划分析如何通过阴极中的人工流来提高效率和电流密度。这种液体内部的混合被多次提出，以改善传质。在文献中多次强调过电压的重要性;然而，迄今为止，从未详细或定量地研究过它们的影响。通过耦合电动力学、流体动力学和电化学，该模型将成为LMB详细模拟的基础。在未来，它可以很容易地补充，例如通过金属间相的模型，以研究电池中的其他过程。

项目成果

Numerical simulation of mass transfer enhancement in liquid metal batteries by means of electro-vortex flow

电涡流增强液态金属电池传质的数值模拟

• DOI: 10.1016/j.powera.2020.100004
• 发表时间: 2020
• 作者: N. Weber;M. Nimtz;P. Personnettaz;T. Weier;D. Sadoway
• 通讯作者: D. Sadoway

Effects of current distribution on mass transport in the positive electrode of a liquid metal battery

电流分布对液态金属电池正极传质的影响

• DOI: 10.22364/mhd.56.2-3.16
• 发表时间: 2020
• 作者: P. Personnettaz;S. Landgraf;M. Nimtz;N. Weber;T. Weier
• 通讯作者: T. Weier

Solutal buoyancy and electrovortex flow in liquid metal batteries

液态金属电池中的溶液浮力和电涡流

• DOI: 10.1103/physrevfluids.5.074501
• 发表时间: 2020
• 期刊: Physical Review Fluids
• 影响因子: 2.7
• 作者: W. Herreman;S. Bénard;C. Nore;P. Personnettaz;L. Cappanera;J.-L. Guermond
• 通讯作者: J.-L. Guermond

Numerical and experimental investigation of electro-vortex flow in a cylindrical container

圆柱形容器中电涡流的数值和实验研究

• DOI: 10.22364/mhd.56.1.3
• 发表时间: 2020
• 期刊: Magnetohydrodynamics
• 影响因子: 0.7
• 作者: K. Liu;F. Stefani;N. Weber;T. Weier;B. W. Li
• 通讯作者: B. W. Li

Modeling discontinuous potential distributions using the finite volume method, and application to liquid metal batteries

• DOI: 10.1016/j.electacta.2019.06.085
• 发表时间: 2019-06
• 期刊: Electrochimica Acta
• 影响因子: 6.6
• 作者: N. Weber;S. Landgraf;K. Mushtaq;Michael Nimtz;P. Personnettaz;T. Weier;Ji Zhao;D. Sadoway