Protection of Li-metal anode by surface coating to enhance the cycling performance of Li-S batteries

通过表面涂层保护锂金属负极以提高锂硫电池的循环性能

• 批准号: 2486771
• 金额: --
• 依托单位: Swansea University
• 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-2486771
• 关键词: Protection; Li; metal; anode; surface

The performance of Lithium-Sulphur batteries is dependent on interfacial processes occurring at the positive and negative electrodes. For example, the surface layers that form on the Li-metal anodes are known to affect the kinetics, capacity and overall performance of batteries. Interfacial reactions between the liquid electrolyte and the metal electrodes limit cycle life, voltage window and cause battery degradation. Furthermore, mossy and dendritic growth of Li-metal occurs in the repetitive Li stripping/plating process creating the risk of thermal runaway events, compromising battery safety. Molecular vapor deposition (MVD) is a coating technique which can deposit very thin (few nm) and conformal films on a variety of substrates including those relevant in electrochemical applications such as metallic foils. The chemical nature and thickness of such films can be tuned and tailored for the specific substrate and application. For instance, in the case of metal anodes, the films can be designed in such a way to mitigate the parasitic side reaction at the electrode/electrolyte interface as well as accommodate the volumetric changes helping to maintain the mechanical integrity of the electrode. The aim of the project is to exploit the capability and flexibility of MVD to grow functional thin films that conform to complex substrates such as Li-metal anodes. In particular, the focus would be on the production of protecting coatings of organic and hybrid organic-inorganic polymers with ad-hoc designed functionalities. The outcomes of the proposed research are multiple and include (i) building a fundamental understanding of the effect of tailored surface coatings on electrochemical and mechanical properties of Li-metal anodes, (ii) to develop functional coatings and their deposition methodology for high performance Li-S batteries, (iii) to widen the applications of MVD techniques to the field of energy storage devices and (iv) provide solutions and improve cycle life of OXIS Ltd Li-S batteries.

锂硫电池的性能取决于正负电极处发生的界面过程。例如，已知在锂金属阳极上形成的表面层会影响电池的动力学、容量和整体性能。液体电解质和金属电极之间的界面反应限制了循环寿命、电压窗口并导致电池退化。此外，锂金属的苔藓状和树枝状生长发生在重复的锂剥离/电镀过程中，产生热失控事件的风险，损害电池安全性。分子气相沉积（MVD）是一种涂覆技术，其可以在各种基底上存款非常薄（几nm）且保形的膜，所述基底包括与电化学应用相关的那些基底，例如金属箔。这种膜的化学性质和厚度可以针对特定的基底和应用进行调整和定制。例如，在金属阳极的情况下，膜可以以这样的方式设计，以减轻电极/电解质界面处的寄生副反应以及适应有助于保持电极的机械完整性的体积变化。该项目的目的是利用MVD的能力和灵活性来生长符合锂金属阳极等复杂基底的功能薄膜。特别是，重点将是生产具有特别设计功能的有机和混合有机-无机聚合物的保护涂层。拟议研究的成果是多方面的，包括（i）建立对定制表面涂层对锂金属阳极电化学和机械性能影响的基本理解，（ii）开发用于高性能Li-S电池的功能涂层及其沉积方法，（iii）将MVD技术的应用扩展到能量存储设备领域，以及（iv）提供解决方案并提高OXIS Ltd Li-S电池的循环寿命。