Ceramic electrolyte design mitigating dendrites and voids at the Li anode

陶瓷电解质设计可减少锂阳极的枝晶和空隙

• 批准号: 2759597
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2759597
• 关键词: Ceramic; electrolyte; design; mitigating; dendrites

The demand for energy storage devices has never been greater. Lithium ion batteries have played an important role in the development of portable electronics due to their high energy densities. They are a key technology in enabling the electrification of transport and the move away from the internal combustion engine. In order to support the transition to renewable energy sources and to fully electrify transport, new materials and battery technologies will be needed. For example, solid state electrolytes make the use of a lithium metal anode possible, significantly increasing the energy safety, i.e. extending driving range. However important challenges remain to be solved if practical solid-state batteries with a lithium anode and ceramic electrolyte are to be realised. During cycling of a solid-state battery with a lithium metal anode, lithium metal is plated and stripped. This give rise to challenges at the lithium-solid electrolyte interface: how to mitigate the formation of voids at the interface on discharge (stripping) and how to suppress dendrite formation on charging (plating). We have shown the detrimental effects of voiding and have made important progress in understanding lithium dendrite growth, which ultimately leads to cell failure. This fundamental understanding has raised the possibility of controlling both the surface and bulk morphology of the ceramic electrolyte as a means of suppressing voids and dendrites, crucially at practical current densities and pressures. It is these topics that this studentship will investigate. Firstly, the surface of the solid electrolyte in contact with lithium will be modified to prevent voiding and significantly increase the stripping current density. Secondly new understanding of lithium dendrite penetration will be exploited to control the solid electrolyte morphology to realise higher current densities without dendrite growth and short-circuiting. This will also contribute to the understanding of the mechanics of sulphide-based electrolytes.Controlling the surface and bulk morphology of sulphide-based solid electrolytes and understanding the relationship between these factors and the performance of the lithium anode is scientifically and technically challenging. This project will involve designing and developing new techniques to prepare solid electrolytes with different bulk and surface morphologies, to characterise them and to fabricate cells and investigate their performance. These results will be used to produce optimised morphologies. This project will involve a number of techniques to control the morphology, such as 3D printing, hot pressing, spark plasma sintering and other materials processing methodologies. The electrolytes will be incorporated in electrochemical cells and testing such as cycling and EIS will be will be used to assess changes in performance. Scanning electron microscopy and tomography will provide complementary data.This project falls within the EPSRC Physical Sciences and Energy and decarbonisation research areas.The studentship is funded as part of the Faraday Institution's solid-state battery project, SOLBAT, and will collaborate with the other partners involved in the project. This is a 4-year Faraday Institution Studentship (part of the course fee paid from Oxford Materials funds)

对储能设备的需求从未如此之大。锂离子电池由于其高能量密度，在便携式电子产品的发展中发挥了重要作用。它们是实现运输电气化和摆脱内燃机的关键技术。为了支持向可再生能源过渡并实现交通全面电气化，需要新材料和电池技术。例如，固态电解质使锂金属阳极的使用成为可能，显着提高了能源安全性，即延长了行驶里程。然而，如果要实现具有锂阳极和陶瓷电解质的实用固态电池，仍然需要解决重要的挑战。在具有锂金属阳极的固态电池的循环过程中，锂金属被镀覆和剥离。这给锂-固体电解质界面带来了挑战：如何减轻放电（剥离）时界面处空隙的形成以及如何抑制充电（电镀）时枝晶的形成。我们已经展示了空洞的有害影响，并在了解锂枝晶生长（最终导致电池故障）方面取得了重要进展。这一基本认识提高了控制陶瓷电解质的表面和整体形态的可能性，作为抑制空隙和枝晶的手段，关键是在实际电流密度和压力下。本次奖学金将研究的正是这些主题。首先，对与锂接触的固体电解质表面进行改性，以防止空洞并显着提高剥离电流密度。其次，将利用对锂枝晶渗透的新理解来控制固体电解质形态，以实现更高的电流密度，而无需枝晶生长和短路。这也将有助于理解硫化物基电解质的力学原理。控制硫化物基固体电解质的表面和体相形态并理解这些因素与锂负极性能之间的关系在科学和技术上都具有挑战性。该项目将涉及设计和开发新技术来制备具有不同体积和表面形态的固体电解质，表征它们并制造电池并研究其性能。这些结果将用于产生优化的形态。该项目将涉及多种形态控制技术，如3D打印、热压、放电等离子烧结和其他材料加工方法。电解质将被纳入电化学电池中，并且将使用循环和 EIS 等测试来评估性能变化。扫描电子显微镜和断层扫描将提供补充数据。该项目属于 EPSRC 物理科学以及能源和脱碳研究领域。该学生奖学金是法拉第研究所固态电池项目 SOLBAT 的一部分，并将与其他合作伙伴合作参与该项目。这是为期 4 年的法拉第学院学生奖学金（部分课程费用由牛津材料基金支付）