Mechanosynthesis of Energy Materials

能源材料的机械合成

• 批准号: EP/X040305/1
• 负责人: Anthony West
• 金额: $ 68.71万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX040305%2F1
• 关键词: Mechanosynthesis; Energy; Materials

This proposal focuses on mechanochemical synthesis as a relatively new method to prepare oxide and mixed anion materials for energy applications. Ball milling is widely used to reduce particle size of reagents, increase their surface areas and increase their reactivity before subsequent high temperature reaction. By using high energy, planetary ball mills, reaction can be carried out to completion at ambient temperatures without the need for follow-on high temperature reaction. A major advantage is the possible preparation of new materials that are unstable at high temperatures and cannot be prepared by traditional routes. The method has been used with some recent success to synthesise new cathode materials for lithium batteries. This proposal aims to establish the conditions for successful use of mechanochemical synthesis as a versatile synthesis procedure and to achieve this by a targetted programme on materials with disordered rock salt crystal structures. There is much scope, by doping and compositional control to achieve reproducible, high charge-discharge capacity materials that have long cycle lives.Rechargeable lithium batteries provide a major source of energy worldwide that are used to power a wide range of portable electrical devices, hybrid and all-electric vehicles, together with large-scale power station load levelling installations linked to the increasing use of wind and solar renewable sources of energy. The batteries range from miniature-scale devices that can be implanted into the human body to megawatt-scale energy storage as part of electricity grid networks. Although current lithium battery technologies are well-established, there is still a great need for improved systems with the objectives of higher energy storage capacity, increased cycle lifetimes and improved environmental compatibility through development of non-toxic and lower cost alternatives to the use of cobalt as a key redox active component of cathodes.The development of new lithium cathodes requires synthesis methods which can be scaled up to give materials that behave reproducibly during battery charge - discharge over many cycles without loss of performance. Several groups of materials have undergone intensive research and development as potential substitutes for LiCoO2, including three groups with rock salt-related crystal structures. These are: layered structures similar to LiCoO2, but with Co replaced by other transition metal combinations; more recently, similar layered structures with a higher Li content that are of particular interest for their high capacities and oxygen redox contributions to capacity; most recently, cubic disordered rock salt structures which have a deceptively simple crystal structure that has cations distributed at random over octahedral sites in a cubic close packed anion sublattice. These latter materials are the main focus of this proposal, both to optimise operational variables using mechanosynthesis and to target new compositions in a poorly-studied family of materials that have considerable potential as lithium battery cathodes.Understanding of these disordered rock salt structure materials is incomplete due to a combination of their nanoscale size, compositional uncertainty, especially concerning their oxygen stoichiometry, their local crystal structures with possible ordered domains or defect clusters and their surface structures which in many cases are atmosphere sensitive. Many have high charge storage capacities but correlations between electrochemical performance, materials synthesis procedures and structural / compositional characteristics are not well established. Many new materials will be prepared during this project, better understanding of the electrochemical properties of disordered rock salt structures gained and guidelines established for wider use of the mechanosynthesis technique.

该提案的重点是机械化学合成作为一种相对较新的方法来制备用于能源应用的氧化物和混合阴离子材料。球磨广泛用于减小试剂的粒度，增加其表面积，并在随后的高温反应之前增加其反应性。通过使用高能行星式球磨机米尔斯，反应可以在环境温度下进行至完全，而不需要后续的高温反应。一个主要的优点是可以制备在高温下不稳定并且不能通过传统途径制备的新材料。该方法最近已成功用于合成锂电池的新阴极材料。该提案旨在建立成功使用机械化学合成作为通用合成程序的条件，并通过对具有无序岩盐晶体结构的材料的有针对性的计划来实现这一目标。通过掺杂和成分控制，可以获得具有长循环寿命的可再生、高充放电容量的材料。可充电锂电池在全球范围内提供了主要的能源，用于为各种便携式电气设备、混合动力和全电动汽车提供动力，与此同时，大规模发电站的负荷平衡装置与风能和太阳能可再生能源的日益使用有关。电池的范围从可以植入人体的微型设备到作为电网网络一部分的兆瓦级能量存储。尽管目前的锂电池技术已经很成熟，但仍然非常需要以更高的能量存储容量为目标的改进系统，通过开发非-使用钴作为阴极关键氧化还原活性成分的有毒且成本较低的替代品。新锂阴极的开发需要可以扩大规模的合成方法，以提供在电池充电-放电过程中经过许多次循环而表现可再现而性能不损失的材料。几组材料已经进行了深入的研究和开发，作为LiCoO 2的潜在替代品，包括三组具有岩盐相关晶体结构的材料。这些是：- 类似于LiCoO 2的层状结构，但是Co被其它过渡金属组合替代;最近，具有更高Li含量的类似层状结构由于其高容量和氧氧化还原对容量的贡献而受到特别关注;最近，具有看似简单的晶体结构的立方无序岩盐结构，阴离子亚晶格。这些后一种材料是该提议的主要焦点，既可以使用机械合成优化操作变量，也可以在研究不足的材料家族中寻找新的组合物，这些材料具有相当大的潜力作为锂电池阴极。由于它们的纳米尺寸，成分不确定性，特别是关于它们的氧化学计量，它们的局部晶体结构具有可能的有序畴或缺陷簇，以及它们的表面结构在许多情况下对大气敏感。许多具有高电荷存储容量，但电化学性能，材料合成程序和结构/组成特性之间的相关性还没有很好地建立。在该项目期间将制备许多新材料，更好地了解无序岩盐结构的电化学性质，并为更广泛地使用机械合成技术制定指导方针。