CAREER: Towards a Comprehensive Theoretical Framework to Predict Multiscale and Multicomponent Electrolyte Transport in Porous Media

为了应对气候变化并努力实现可持续的未来，能源和环境技术的进步至关重要。这些技术包括(I)电化学电容器(ECs)，这是一种只需几秒钟就能充电的储能设备，以及(Ii)电容式去电离器(CDI)，它是一种通过通电去除水中盐分的脱盐设备。ECS和CDI都使用多孔电极来最大化性能。这些电极由一个复杂的孔洞网络组成，当施加电压时，离子可以通过这些孔洞移动。虽然对这些技术的材料研究激增，但对控制EC和CDI性能的因素的了解仍然有限。通过将应用数学技术与现代计算能力相结合，该奖项将开发和实验验证计算机模拟，以了解多种离子物种如何在孔隙网络中移动。该奖项的结果将加速ECS和CDI的设计和放大，例如，通过3D打印电极的优化设计。综合教育计划将纳入研究成果，以创建每个人都可以使用的基于网络的互动模拟，设计一个开放的在线课程，为未来的可持续经济劳动力做准备，并通过科学研讨会扩大第一代初中生的参与。多组分电解质传输的基本挑战是系统由多个长度和时间尺度组成，并且物质的传输是通过电场耦合的。现有的建模方法无法捕捉在多孔电极中观察到的实验趋势，因为它们侧重于无限制几何结构中的二元电解质，而忽略了多个电解质和受限几何结构的影响。这一奖项旨在弥合电动力学领域的这一重大知识差距。通过利用孔隙的稀薄，该奖项将开发一种基于微扰展开的新理论框架，类似于流体力学中的润滑理论，将克服现有方法的局限性。具体地说，这项工作将(I)为离子价态、扩散系数、大小和相对德拜长度的不受限制的组合建立带电圆柱形孔内任意数量离子的传输模型，(Ii)制定并实验验证预测离子通过复杂孔网络的离子传输的新理论框架，以及(Ii)研究氧化还原反应和多孔介质中的双层的组合效应，以表征EC和CDI的结构-属性-性能关系。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

To combat climate change and work towards a sustainable future, advancements are crucial in energy and environmental technologies. These technologies include (i) electrochemical capacitors (ECs), which are energy storage devices that only require a few seconds to charge, and (ii) capacitive deionizers (CDIs), which are desalination devices that remove salt from water by applying electricity. Both ECs and CDIs employ porous electrodes to maximize performance. These electrodes consist of a complex network of pores through which ions move when voltage is applied. While materials research on these technologies has proliferated, understanding of the factors controlling the performance of EC and CDI remains limited. By combining applied mathematics techniques with modern computing capabilities, this award will develop and experimentally validate computer simulations to understand how multiple ionic species move through pore networks. The results from this award will accelerate the design and scale-up ECs and CDIs, for instance, through optimal design of 3D-printed electrodes. The integrated education program will incorporate research outcomes to create web-based interactive simulations that are available for everyone, design an open online course, to prepare the future sustainable economy workforce, and broaden the participation of first-generation middle and high school students through scientific workshops. Fundamental challenges in multicomponent electrolyte transport are that the systems consist of multiple lengthscales and timescales, and the transport of species is coupled through an electric field. Existing modeling approaches are unable to capture experimental trends observed in porous electrodes because they focus on binary electrolytes in unconfined geometries and overlook the impact of multiple electrolytes and confined geometries. This award aims to bridge this major knowledge gap in the field of electrokinetics. By exploiting the thinness of the pores, this award will develop a new theoretical framework based on perturbation expansions, akin to lubrication theory in fluid mechanics, that will overcome the limitations of existing approaches. Specifically, the work will (i) model transport of an arbitrary number of ions inside a charged cylindrical pore for an unrestricted combination of ion valences, diffusivities, size, and relative Debye length, (ii) formulate and experimentally validate a new theoretical framework that predicts ion transport through a complex network of pores, and (ii) investigate the combined effect of redox reactions and double layers in porous media to characterize structure-property-performance relationships for EC and CDI.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.