柔性可充锌锰电池多价态存储机制和衰减特性研究

Flexible energy storage devices play an important role in wearable electric devices. Traditionally, energy storage devices have many shortcomings, including the low activity of electrode materials, the strong corrosion of electrolyte, and the high rigidity of fabrication, which limit the application to wearable devices and special-shaped space. Flexible rechargeable zinc-multivalent manganese oxide battery has outstanding advantages especially in safety. However, some mechanisms are unclear, including the conversion between valence ions and the effect of this conversion. In this project, the mix-valence manganese oxide (MnOn) is used as electrode materials of flexible batteries, which is prepared by the controllable preparation of manganese dioxide (MnO2) and limited reducing activation. As a result, the electrochemical reactions are activated and the cell reactions are prolonged. The correspondence of reducing method, microstructure, component ratio and electrochemical property by modern material characterization technology and property test. The fabrication of low contact resistance and deformation resistance devices is obtained by optimizing device structure. Depend on the evaluation of mechanical and electrochemical properties, the interfacial combination between electrode materials and electrolyte and the ion diffusion can be explored. It is devoted to clarify the influence of reducing vapor activation and cell fabrication based on first principles and molecular dynamics simulation, as well as the relationship between the component of MnOn and the electrochemical property. At last, the energy-storage and failure mechanism are analyzed. This research will provide insight to improve the fabrication efficiency of electrode materials of flexible batteries and offer scientific basis and technological support for the development of wearable energy storage devices.

作为可穿戴电子设备的核心元件，各类柔性储能器件已成为重大需求。其中，柔性可充锌锰电池具有安全环保的突出优势。但是，可充锌锰电池的储能机理，尤其是当多价态锰离子共存时，其充放电过程中各价态离子间的转化及对电池反应驱动力和可逆性、离子扩散速率和反应速率的作用等，尚未完全阐明。本项目拟以提高电池储能性能为目的，改进电池柔性为导向，通过限量还原方法和无粘结剂电极设计，构筑具有多价态锰离子共存和优异变形性能的柔性锌锰电池。基于异价态离子的添加剂效应，通过准动态演化研究，深度剖析多价态锰氧化物的电极反应过程及其微观作用机制。通过复杂服役空间模拟，研究多价态体系与电解质和导电框架界面和电化学性能及宏观变形性能的影响规律。进一步结合密度泛函理论和分子动力学模拟，研究多价态体系分布和离子嵌入储存的关系，揭示性能衰减机理和器件失效机制。为柔性可充锌锰电池在柔性储能器件中的应用提供理论依据和技术支持。

随着科学技术快速发展，众多可穿戴柔性电子产品出现，作为可穿戴电子设备的核心元件，各类柔性储能器件已被广泛的研究。其中，柔性可充锌离子电池由于绿色环保、安全性高等特点，在可穿戴领域已经成为人们的研究热点。锰基氧化物作为一种资源丰富、环境友好、价格低廉的功能材料，在电化学方面表现出优秀的性能，是柔性可充锌离子电池的理想正极材料。但是，锰基氧化物作为柔性可充锌离子电池正极的储能机理，尤其是当多价态锰离子共存时，其充放电过程中各价态离子间的转化及对电池反应驱动力和可逆性、离子扩散速率和反应速率的作用等，尚未完全阐明。本项目通过水合肼限量还原MnO2的方法设计多价态MnO2正极材料，构筑了具有多价态锰离子共存和优异变形性能的柔性可充锌离子电池。基于异价态锰离子的添加剂效应，通过准动态演化研究，深度剖析多价态锰氧化物的电极反应过程及其微观作用机制。通过复杂服役空间模拟，研究多价态体系与电解质和导电框架界面和电化学性能及宏观变形性能的影响规律。进一步结合密度泛函理论和分子动力学模拟，研究多价态体系分布和离子嵌入储存的关系，揭示性能衰减机理和器件失效机制。为柔性可充锌离子电池在柔性储能器件中的应用提供理论依据和技术支持。