Modeling of Nano-architected Electrodes with Elastic Instabilities: The Role of Buckling on Electrochemical Performance

下一代锂金属电极的开发可以彻底改变储能行业，因为这些材料的理论能量密度大大超过了当前电池的性能。然而，在实践中，由于锂的插入/反应，主体材料的大体积膨胀会导致大的变形和载荷，从而导致断裂、粉碎，最终导致设备故障。该奖项将用于研究弹性不稳定性（如屈曲）在纳米结构电池电极设计中的应用。本研究通过阐明屈曲可以改善电化学和机械电池性能的方式以及改善程度，将促进电化学机械科学的发展。至关重要的是，这项研究将使实验学家能够快速原型和测试下一代电极，并为这些设计的潜在好处提供明确的指导方针。最后，所进行的研究不仅限于锂离子电极，而且可以提高我们对几种化学机械系统的理解，如催化系统和固体氧化物燃料电池等，这将促进国家的健康，繁荣和福利。这项研究将对美国的教育产生广泛的影响，它将有助于培养对固体力学和电化学有多学科理解的下一代本科生和研究生。培养这样的未来科学家对美国能源工业至关重要。最后，该奖项将通过开发用于清洁能源存储的锂离子电池的物理、制造和部署方面的动手实验，支持向代表性不足的K-12学生提供服务。依靠锂金属的下一代锂离子电极的发展必然需要适应这些材料在锂化过程中产生的大变形。弹性不稳定性，特别是屈曲，是一种可能的机制，即材料的变形可以与有限的应力产生相适应。然而，目前还没有数值工具来实现合理设计纳米结构的可弯曲电极。我们的方法将利用两种类型的模型：i)一个详细的三维，全耦合的有限元模型，它精确地解决了这些复杂系统在实验精确的电化学边界条件下的瞬态行为；ii)一个简化的降阶模型，它集成了足够的物理，以一小部分计算成本提供合理准确的电化学性能估计。这些模型将被实验验证，并应用于开发新的设计和设计指南的纳米结构电极的弯曲。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The development of next generation lithium-metal electrodes can revolutionize the energy storage industry as the theoretical energy density of these materials greatly overshadows current battery capabilities. In practice, however, the high-volume expansion of the host material due to lithium insertion/reaction results in large deformations and loads which can cause fracture, pulverization, and eventually device failure. This award will support research towards investigating the use of elastic instabilities, such as buckling, in the design of nano-architected battery electrodes. This research will promote the electrochemo-mechanical sciences by elucidating the way buckling can improve electrochemical and mechanical battery performance, and the degree of improvement. Critically, this research will enable experimentalists to rapidly prototype and test next generation electrodes as well as provide a clear guideline as to the potential benefits of these designs. Finally, the research performed is not restricted to Li-Ion electrodes but can improve our understanding of several chemo-mechanical systems such as systems for catalysis and solid oxide fuel cells amongst others, which will advance the national health, prosperity, and welfare. The research will have a broad impact on U.S. education where it will aid in the training of a diverse group of next generation undergraduate and graduate students with a multi-disciplinary understanding of mechanics of solids and electrochemistry. The training of such future scientists is critical to the U.S. energy industry. Finally, the award will support outreach to underrepresented K-12 students through the development of hands on experiments on the physics, manufacturing, and deployment of Li-Ion batteries for clean energy storage.The development of next-generation Li-Ion electrodes relying on lithium-metals will necessarily require the means of accommodating the large deformations which are incurred by these materials during the lithiation process. Elastic instabilities, in particular buckling, is one possible mechanism whereby deformation of the material can be accommodated with limited generation of stresses. At present, however, there is no numerical tool to enable the rational design of nano-architected electrodes that buckle. Our approach will make use of two types of model: i) a detailed three-dimensional, fully-coupled finite element model which accurately resolves the transient behavior of these complex systems under experimentally accurate electrochemical boundary conditions, and ii) a simplified reduced order model which integrates enough physics to provide a reasonably accurate estimation of the electrochemical performance at a fraction of the computational cost. These models will be experimentally validated and applied towards developing novel designs and design guidelines for nano-architected electrodes which buckle.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.