Understanding the Structural Transformations of Aluminum Foil Anodes during Electrochemical De(alloying) for Sustainable Lithium-ion Batteries

了解可持续锂离子电池电化学脱（合金）过程中铝箔阳极的结构转变

• 批准号: 2321486
• 负责人: Arumugam Manthiram
• 金额: $ 48.95万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2321486&HistoricalAwards=false
• 关键词: Understanding; Structural; Transformations; Aluminum; Foil

Lithium-ion batteries will play an essential role in the transition to a sustainable economy by enabling the adoption of electric vehicles and renewable energy sources. However, as Lithium-ion batteries production grows rapidly, there are serious supply chain risks associated with the use of critical minerals (e.g., nickel, cobalt, graphite), which may restrict domestic production. Meanwhile, continuous improvements to lithium-ion battery performance – particularly energy density – are needed to meet the demands of commercial and military applications. To that end, it is imperative to develop battery anodes with higher lithium-storage capacity and lower cost than traditional graphite anodes. One promising, yet largely unexplored, alternative to graphite is aluminum (Al) foil, which can increase battery energy density by up to 40%, while improving safety, fast charging capability, and cost. However, research on Al foil anodes is in its infancy, and the fundamental mechanisms underlying the structural transformations of Al foil anodes during electrochemical (de)alloying must be uncovered to improve their poor cycle life. The fundamental research project will fill this knowledge gap through an interdisciplinary research approach that integrates materials science and electrochemical engineering. The project team will work with a local public school and the Ysleta Del Sur Pueblo reservation students and provide outreach on topics of the importance of clean energy technologies and opportunities in STEM careers. Aluminum foil anodes undergo fundamental changes in microstructure during battery formation (i.e., the first cycle), which largely control the electrochemical performance in subsequent cycles. It is hypothesized that the same mechanochemical processes, which cause dramatic structural changes during formation, when repeated continuously, are responsible for the rapid capacity loss during cycling. The goal of this research project is to understand: (i) how the structure and composition of the pristine Al foil anode, along with the kinetics of nucleation, phase transition, and solid-state diffusion, control the structural transformations during formation, and (ii) how the foil microstructure resulting from formation, and its evolution during cycling, control the failure modes of diffusional trapping and mechanical degradation. The dynamic electrochemical kinetics of these processes will be evaluated simultaneously with cycle life by conducting operando impedance spectroscopy in lithium iron phosphate full cells. An extensive suite of materials characterization techniques will be employed at various stages during formation and extended cycling to understand the mechanisms of structural transformation and identify the associated failure modes. These techniques will be used to interrogate Al foil anodes with diverse composition and microstructure, ranging from pure Al to nanocomposite foils. The structural transformations during formation will be correlated to operando kinetic measurements to establish quantitative relationships between initial foil structure/composition, electrochemical processing conditions, and the resulting foil microstructure. Finally, by correlating the microstructure after formation to the measured cycle life, and identifying the root causes of failure with advanced post-mortem materials characterization techniques, comprehensive processing-structure-performance relationships will be established to guide rational design of Al foil anodes with improved cycle life. This novel strategy of using the battery formation process as the final step of electrode manufacturing enables control of the microstructure through electrochemical engineering, which will lead to a paradigm shift in the research efforts to develop Al foil anodes.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.

锂离子电池将通过实现电动汽车和可再生能源的采用，在向可持续经济的过渡中发挥重要作用。但是，随着锂离子电池的生产迅速增长，与关键矿物（例如镍，钴，石墨）相关的严重供应链风险可能会限制国内生产。同时，需要对锂离子电池性能（尤其是能量密度）的持续改进来满足商业和军事应用的需求。为此，与传统石墨阳极相比，必须开发具有更高锂存储能力且成本更低的电池阳极。石墨的替代方案是一种承诺，但基本上是出乎意料的，是铝（AL）箔，它可以将电池能量密度提高高达40％，同时提高安全性，快速充电能力和成本。然而，对铝箔阳极的研究仍处于起步阶段，并且必须发现电化学（DE）合金的铝箔阳极结构转化的基本机制，以改善其循环寿命差。基本研究项目将通过将材料科学和电化学工程整合的跨学科研究方法填补这一知识差距。项目团队将与当地的公立学校和Ysleta del Sur Pueblo保留专业的学生合作，并提供有关清洁能源技术和STEM职业机会重要性的主题。在电池形成过程中微观结构（即第一个周期）的基本变化下，铝箔阳极在很大程度上控制了随后的周期中的电化学性能。假设相同的机械化学过程，在持续重复时会在形成过程中引起急剧的结构变化，这是循环过程中快速容量损失的原因。该研究项目的目的是了解：（i）原始箔阳极的结构和组成以及核，相过渡和固态扩散的动力学，控制形成过程中的结构转换，以及（ii）如何从形成产生的箔微观结构在循环中产生的箔微观结构，及其在循环中的进化，控制循环模式的散射模式和机制的扩散序列和机制。这些过程的动态电化学动力学将通过在磷酸锂全细胞中进行操作的抗性光谱来简单地评估循环寿命。在编队期间，将在各个阶段采用一系列材料表征技术，并扩展循环以了解结构转化的机制并确定相关的故障模式。这些技术将用于询问从纯Al到纳米复合材料的潜水员组成和微观结构的Al Foil阳极。编队过程中的结构转换将与操作动力学测量相关，以在初始箔结构/组成，电化学加工条件与所得的箔微结构之间建立定量关系。最后，通过将微观结构与测量的周期寿命相关联，并通过高级术后材料表征识别失败的根本原因，将建立全面的处理结构 - 绩效关系，以指导具有改善循环寿命的Al Foil Anodes的合理设计。这种新的使用电池形成过程作为电极制造的最终步骤的新型策略可以通过电化学工程来控制微观结构，这将导致研究工作的范式转变，以开发Al Foil Anodes。该奖项反映了NSF的法规任务，并被认为是通过基金会的知识优点和广泛的criter criter criter criteria criteria criter criter criteria criteria criter criteria criteria criteria criteria criteria criteria criteria criteria criteria criteria criteria criteria criteria criteria均值得一提。