Understanding the activity and stability of electrode materials targeted for clean energy applications through diagnostic impedance measurements

通过诊断阻抗测量了解清洁能源应用电极材料的活性和稳定性

• 批准号: RGPIN-2015-03652
• 负责人: Easton, EBradley
• 金额: $ 3.28万
• 依托单位: University of Ontario Institute of Technology
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649894
• 关键词: Understanding; activity; stability; electrode; materials

This research program focuses on fundamental studies of advanced materials targeted for electrochemical energy systems. Specifically metal/metal-alloy nanoparticles, advanced carbon materials as well as combinations of metals nanoparticles with these carbons. Such materials are at the heart of numerous electrochemical energy technologies, including fuel cells, electrolyzers and electrochemical/super capacitors. These technologies have the potential to be more widely deployed in the energy landscape provided that improvements can be made in the performance-to-cost ratio of the materials, and also in their durability. In addition to improvements in the materials themselves, improvements are needed in diagnostic tools that can readily assess multiple indicators of the electrode state-of-health.******This proposal is focused on the study and enhancement of new electrode materials and the refinement of electrochemical impedance spectroscopy (EIS) measurements as a go-to diagnostic tool. We have recently developed an EIS-based diagnostic methods that can clearly elucidate the mode of electrode degradation occurring. Specific changes in the EIS profiles occur upon degradation that are characteristic of specific catalyst layer degradation processes, including the degradation of the carbon support and the ionomer. Furthermore, we have modified the transmission line EIS model so that double-layer capacitance (Cdl) can be separated from faradaic pseudo-capacitance (CF) originating from Hupd on Pt. Moreover, we have been able to show that magnitude of CF originating from Hupd is proportional to the Pt surface area, yielding potential-dependent constants that enable accurate measurements of the electrochemically active surface area of a poly-crystalline Pt electrodes from EIS measurements.******Together this suite of EIS-based tools has enormous potential to study both the stability of an electrode and also surface processes in applications beyond typical Pt/C electrodes. Thus, our ongoing studies will focus on novel electrode materials, employing EIS to elucidate how the electrode surface is changing over time and also to quantify active surface species, both metallic and carbon-based, and how this impacts activity. Longer-term objectives include an examination of the relationships between structure and relevant properties such as conductivity, electrochemically active surface area, catalytic activity, capacity and performance. Furthermore, we will seek to extend our EIS methodology so that it can be applied universally in the quantification of electrochemically addressable redox species bound to an electrode surface.**

该研究计划的重点是针对电化学能源系统的高级材料的基本研究。特别是金属/金属合金纳米颗粒，晚期碳材料以及金属纳米颗粒与这些碳的组合。此类材料是众多电化学能源技术的核心，包括燃料电池，电解液和电化学/超级电容器。如果可以在材料的性能与成本率和耐用性的情况下进行改进，则这些技术有可能在能源景观中更广泛地部署。除了改进材料本身外，还需要改进诊断工具，这些工具还需要评估电极状况良好的多个指标。******该建议集中在研究和增强新电气材料的研究和增强电力化学材料以及对电化学侵害光谱（EIS）测量的改进，作为一种诊断诊断工具。我们最近开发了一种基于EIS的诊断方法，该方法可以清楚地阐明发生电极降解的方式。 EIS轮廓的特定变化发生在降解后发生，这些是特定催化剂层降解过程的特征，包括碳支持和离子体的降解。此外，我们已经修改了传输线EIS模型，以便可以将双层电容（CDL）与源自PT上HUPD的Faradaic Pseudo-Capitance（CF）分开。此外，我们已经能够证明，源自HUPD的CF幅度与PT表面积成正比，产生了潜在的依赖性常数，可以准确测量多晶PT电极的电化学活跃的表面积，而EIS的典型工具都可以通过EIS的效率进行了典型的应用。 PT/C电极。因此，我们正在进行的研究将集中于新型电极材料，采用EIS来阐明电极表面如何随着时间的流逝而变化，并量化金属和碳基的活性表面物种，以及这如何影响活性。长期目标包括检查结构与相关特性之间的关系，例如电导率，电化学活性表面积，催化活性，能力和性能。此外，我们将寻求扩展我们的EIS方法论，以便将其普遍应用于与电极表面结合的电化学上可寻址的氧化还原物种的定量。**