Identification of failure mechanisms in Ni rich cathodes relevant to the safety of a battery cell

识别与电池安全相关的富镍正极的失效机制

• 批准号: 2570149
• 金额: --
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2570149
• 关键词: Identification; failure; mechanisms; Ni; rich

This project offers the opportunity to study the safety behaviour of Ni rich cathode materials at different SoH's and identify changes/weaknesses in the material with age. The primary focus is to analyse how safety characteristics evolve with the lifetime of the cathode material (focus on commercially available NMC 811) conducting abusive tests at different SoH's. Macro-, micro- and nano-CT measurements will inform in-situ microstructural changes within the battery, in situ XRD will elucidate structural changes in the cathode materials. Post-test analysis on the cathode materials - conducted using the facilities at JM (potentially supported by the University partner to fill in gaps) - will be undertaken to investigate compositional and structural changes at both the electrode's surface and the electrolyte. In tandem, electrochemical testing could be undertaken, alongside a portfolio of additional techniques including calorimetry, colorimetry thermal imaging and acoustic measurements to inform SoH.We will pursue parallel work streams on proprietary and model materials, the latter providing a platform for technique development and wider opportunities for publication without compromising IP, as well as alignment to the Faraday Institution projects, providing opportunities for wider correlative studies.Main Objectives:- Link micro/structural changes in the electrodes with changes in the electrochemical and ultimately the safety behaviour of the cells.- Understand the influence of physical product features on safety properties (e.g. primary and secondary particle size, density).- Develop a non-destructive test to determine the SoH of a cell.- Develop a strategy to further improve the safety performance of eLNO materials by using learnings to inform product development.Year 1: Development of a strategy and a detailed test plan for pouch cells including electrochemical characterisation (e.g EIS, GITT or PITT) and abusive safety tests. Abusive tests include, amongst others, accelerated rate calorimetry (ARC), nail penetration, overcharging and crush testing. Conduct first electrochemical abusive tests on pouch cells, post mortem X-ray imaging and tear down analysis. Establish links with Faraday Institution projects.Year 2: Development methods for correlated thermal/mechanical abuse tests with operando X-ray imaging. Systematic studies of NMC vs eLNO materials to determine safety and SoH characteristics, and development/implementation of accelerated stress tests. Beam time applications where appropriate, focussing on non-proprietary materials.Year 3: Correlation between chemical/morphological evolution in response to AST's and establish links to durability/failure. Establish platform capability for evaluation of safety performance for materials across time/length scales. Translation of synchrotron tools to lab environment.Year 4: Dissemination of findings, contribution to new standards/methodologies for cell safety. This project builds on, and is complementary to, an existing PhD project in collaboration with UCL (Drasti Patel is currently developing imaging and calorimetry techniques for JM battery materials): it tackles open questions relating to battery safety, but also strongly profits from the fundamental work which has already been conducted.

该项目提供了研究不同SOH的NI丰富阴极材料的安全行为，并随着年龄的增长确定材料中的变化/弱点。主要的重点是分析通过阴极材料的寿命（专注于市售NMC 811）的安全特性如何发展，以在不同的SOH上进行滥用测试。宏观，微观和纳米CT测量值将为电池内的原位微结构变化提供信息，原位XRD将阐明阴极材料中的结构变化。将对使用JM的设施进行的阴极材料进行测试后分析（大学合作伙伴可能支持填补空白） - 将进行研究，以研究电极表面和电解质的组成和结构变化。同时，可以进行电化学测试，以及其他技术组合，包括量热法，比色的热成像和声学测量和声学测量，以告知SOH。我们将寻求平行的工作流程，以实现专有和模型的材料，为后者提供了一个为技术开发和广泛的iP提供的机会，并提供了整个项目，并提供了广泛的iP，并提供了广泛的iP，并提供了广泛的iP，并提供了广泛的范围，并提供了广泛的范围，并提供了广泛的iP，并提供了广泛的材料，并提供了广泛的材料。宗旨： - 将电极的微/结构变化与电化学的变化联系起来，最终将细胞的安全行为联系起来。策略和小袋细胞的详细测试计划，包括电化学表征（例如EIS，GITT或PITT）和滥用安全测试。虐待测试包括加速速率量热法（ARC），指甲穿透，过度充电和压碎测试。对小袋细胞进行首次电化学滥用测试，验尸后成像并拆除分析。与法拉第机构项目建立链接。年2：与Operando X射线成像相关的热/机械滥用测试的开发方法。 NMC与ELNO材料的系统研究，以确定安全性和SOH特征，以及加速压力测试的开发/实施。光束时间应用在适当的地方，重点放在非专有材料上。年3：响应AST的化学/形态演化之间的相关性，并与耐用性/失败建立联系。建立平台能力，以评估跨时间/长度尺度的材料的安全性能。同步器工具向实验室环境的翻译。年4：发现结果，对细胞安全的新标准/方法的贡献。该项目基于与UCL合作的现有博士学位项目的基础（Drasti Patel目前正在开发用于JM电池材料的成像和量热法）：它解决了与电池安全的开放问题，但也从已经进行过的基本工作中获得了大量利润。