Development of operando NMR methods for the characterisation of next generation battery technologies'

该项目属于EPSRC物理科学和能源研究领域。对储能设备的需求从未像现在这样大。由于其高能量密度，锂离子电池在消费电子产品的发展中发挥了关键作用，它们是实现向更绿色能源过渡的关键技术，特别是交通电气化。不幸的是，一种单一的技术并不适合所有的应用，目前的锂离子电池将不能满足其他形式的交通运输的需求，如航空和海运应用-除了锂离子电池的新材料需要锂离子技术。锂空气电池在所有电池技术中提供最高的理论比能量，使其非常适合要求苛刻的应用。新技术使交通网络的其他部分实现电气化，并支持向可再生能源的过渡，这将减少碳排放，并有助于实现气候变化目标。要实现这一潜力，我们需要了解支撑锂空气电池运行的化学和电化学以及影响性能的因素。锂空气电池由锂金属负极和多孔正极组成，由有机电解液隔开。放电时，在正极形成过氧化锂，在随后的充电中被氧化。众所周知，锂空气电池在循环过程中会发生有害的分解反应，导致不想要的副产品。防止这些物种的形成是实现全部潜力的关键。该项目将涉及开发一种手术中多核台式核磁共振(核磁共振)方法，以了解锂空气电池中发生的电化学反应和寄生反应。由于缺乏关于电解液在电池循环过程中如何变化的知识，我们的理解是有限的。电解液也将在实现下一代锂离子电池正极材料方面发挥重要作用。这些阴离子氧化还原材料在高电压下工作，在那里电解液降解显著。了解电池循环过程中电池材料的变化，对于制定防止分解和提高性能的策略至关重要。目前的技术要求在分析之前对细胞进行分解。台式核磁共振在该领域是一项相对较新的技术，它提供了开发一系列新的操作实验的机会，以便在细胞循环时直接探测组件。其他实验技术，如电化学、紫外可见光谱、衍射和差示电化学质谱将被用来提供补充数据。该项目开发的方法论将与其他存储技术相关。该项目由牛津仪器公司共同资助，作为iCASE学生项目的一部分。

This project falls within the EPSRC Physical Sciences and Energy research areas.The demand for energy storage devices has never been greater. Lithium ion batteries have played key role in the development of consumer electronics, due to their high energy densities, and they are a key technology in enabling the transition to greener energy sources, in particular the electrification of transport. Unfortunately a single technology is not suitable for all applications and current lithium ion batteries will not be able to meet the demands of other forms of transport, such as aviation and maritime applications - beyond lithium ion technologies are needed alongside new materials for lithium ion cells. The lithium-air battery offers the highest theoretical specific energy of any battery technology making it well suited to demanding applications. New technology that enables electrification of other parts of the transport network and supports the transition to renewables which will reduce carbon emissions and help meet climate change targets.To realise this potential we need to understand the chemistry and electrochemistry that underpins the operation of lithium-air cells and factors affecting performance. The Li-air battery consists of a lithium metal negative electrode and a porous positive electrode, separated by an organic electrolyte. On discharge, at the positive electrode, lithium peroxide is formed, which is oxidised on subsequent charging. The lithium air battery is known to undergo detrimental decomposition reactions during cycling, leading to unwanted side-products. Preventing the formation of these species is vital to realise the full potential.The project will involve developing an in-operando multinuclear benchtop nuclear magnetic resonance (NMR) methodology to understand the electrochemistry and parasitic reactions taking place in the lithium-air battery. Our understanding is limited due to lack of knowledge on how electrolytes change as a cell is cycled. Electrolytes will also play an important role in enabling the next generation of cathode materials for lithium ion cells. These anionic redox materials operate at high voltages, where electrolyte degradation is significant. Understanding the changes in battery materials as the cell is cycled is crucial to devise strategies to prevent decomposition and improve performance. Current techniques require cells to be dissembled before analysis. Benchtop NMR is a relatively new technique in the field and offers the chance to develop a new range of operando experiments to directly probe components as the cell is cycled. Other experimental techniques, such as electrochemistry, UV-Vis spectroscopy, diffraction and differential electrochemical mass spectrometry will be used to provide complementary data. The methodology developed in this project will be relevant to other storage technologies.The project is co-funded by Oxford Instruments as part of an iCASE studentship.