Investigation and modeling of the microscopic causes for non-linear ageing behavior of carbon-based electrochemical double layer capacitors

碳基电化学双层电容器非线性老化行为的微观原因研究和建模

• 批准号: 236369933
• 负责人: Professor Dr. Dirk Uwe Sauer
• 金额: --
• 依托单位: Center for Ageing, Reliability and Lifetime Prediction of Electrochemical and Power Electronic Systems (CARL)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/236369933?language=en
• 关键词: Investigation; modeling; microscopic; causes; non

Within this research project, the ageing behavior of electrochemical double layer capacitors, below called supercaps, will be systematically investigated. The goal is to achieve a deeper understanding of the physico-chemical processes at each electrode during ageing. Based on the experimental results of post mortem analysis, a physic-chemical model has to be developed. This model has to represent the ageing processes and can be used for life time prediction.Nowadays, a rule of thumb is typically used for life time prediction like Lifetime is halved by 100 mV voltage increase respectively 10 K temperature increase. This rule of thumb is based on extrapolated data of life time test results that have been carried out at elevated temperatures and voltages. However, experimental results show that the ageing behavior of supercap cells cannot be explained in an adequate way by this simple pattern of explanation. With consequent extrapolation these cells would have a lifetime expectancy of more than hundred years at low temperatures respectively low voltages. Therefore, the mechanisms of action of the ageing processes and their dependency on potentials, current rates and temperatures have to be identified within this research project. Based on these results a significantly more precise model for lifetime prediction will be developed.Post mortem analysis will be conducted at commercial carbon-based supercap cells to analyze the physico-chemical ageing processes. For these investigations cells that have already been aged at different ageing conditions can be used. But additional ageing tests will be carried out as well. Thus, structural changes of the electrode surface, as well as on cathode and on anode side, will be detected and a material analysis will be carried out. The results will incorporate into a physic-chemical model that begins on particle level and is able to represent the complex processes within the pores of carbon electrodes as well as at the barrier layer between electrolyte and electrode. Post mortem analysis should be based on the opening of cells that have already been aged in calendric and cyclic ageing tests at the institute of the applicant. Since the ageing conditions of these cells are known it has to be investigated which chemical and electrochemical processes have been initiated and how they influence the cell performance. Furthermore, it has to be analyzed how regeneration processes that were observed in experimental investigations can be explained. During these tests the cell capacitance increased suddenly after a break during the aging test. Finally, by means of the developed physic-chemical a fundamental bechmark of operating strategies and load profiles regarding lifetime of supercaps has to be carried out.

在这个研究项目中，将系统地研究电化学双层电容器（以下称为超级电容器）的老化行为。目标是对老化过程中每个电极的物理化学过程有更深入的了解。基于尸体解剖分析的实验结果，需要建立一个物理-化学模型。该模型必须表示老化过程，并可用于寿命预测。现在，通常使用经验法则进行寿命预测，例如电压增加100 mV，温度增加10 K，寿命减半。这条经验法则是基于在高温和高压下进行的寿命测试结果的外推数据。然而，实验结果表明，这种简单的解释模式不能充分解释超级帽细胞的老化行为。由此推断，这些电池在低温和低电压下的预期寿命将超过100年。因此，老化过程的作用机制及其对电位、电流速率和温度的依赖必须在本研究项目中确定。在这些结果的基础上，将开发出一个更为精确的寿命预测模型。死后分析将在商用碳基超级电池上进行，以分析物理化学老化过程。对于这些研究，可以使用已经在不同老化条件下老化的细胞。但额外的老化测试也将进行。这样，就可以检测到电极表面以及阴极和阳极侧的结构变化，并进行材料分析。研究结果将纳入一个从粒子水平开始的物理化学模型，该模型能够代表碳电极孔隙内以及电解质和电极之间屏障层的复杂过程。死后分析应基于在申请人研究所进行的历法和循环老化试验中已经老化的细胞的打开情况。由于已知这些电池的老化条件，因此必须研究哪些化学和电化学过程已经启动，以及它们如何影响电池性能。此外，还必须分析如何解释在实验调查中观察到的再生过程。在这些测试中，电池电容在老化测试中中断后突然增加。最后，借助已开发的物理化学方法，必须对超级帽的使用寿命进行操作策略和负载概况的基本标记。