【中文摘要】锂离子电池已经广泛应用于各类便携式装置，并有进一步向动力型和微型电池发展的趋势。以最高储锂容量的硅取代现有的石墨基负极材料是提高电池能量密度的有效途径，但硅在嵌脱锂过程中严重的体积变化使电极的结构和循环稳定性迅速下降。研究结果表明，减小硅反应相尺度到亚微米或纳米程度能改善电极的机械和导电稳定性。该项目拟研究实用性强的电沉积技术制备锂离子电池用微米级厚度硅基薄膜负极，通过与金属共沉积，提高沉积层的导电性，确保薄膜厚度的可控性，同时达到改善电极机械强度的目的。另一方面，将发展独特的电极构造，通过调控电极结构和形貌，抑制硅基电极的体积效应，使电极在高储锂容量条件下保持结构稳定。在此基础上，进一步发展与硅基电极相适应的电解质体系，有效提高电极电化学嵌脱锂可逆性，为锂离子电池的新发展奠定基础。
【英文摘要】It is an effective way to improve the battery’ energy density using Si to replace the current commercial carbon anodes, due to Si’ highest Li-storage capacity. However, Si electrodes show poor electrochemical reversibility upon cycling for a drastic volume change of Si (>300%) during the lithium insertion/extraction process. To accommodate the absolute volume change and further enhance the cycling stability, sub-micron and/or nanostructure’ Si have been proposed. This project will prepare micron-scale Si thin film anodes by electrodeposition technique, and co-deposit Si with other metals to improve its’ conductivity ensuring the regulation of Si thin films’ thickness and improving the mechanical strength of Si thin films anodes. On the other hand, the unique structure electrodes will be prepared to reduce the absolute volume change and enhance its’ structural stability at higher Li-storage capacity by regulating the electrodes’ structure and morphology. Based on this, the suitable electrolyte system would be developed matching with Si thin film electrodes to effectively improve its’ electrochemical reversibility, which will lay a foundation for the further development of Li-ion batteries.
【结题摘要】锂离子电池已经广泛应用于各类便携式装置，并有进一步向动力型和微型电池发展的趋势。以最高储锂容量的硅取代现有的石墨基负极材料是提高电池能量密度的有效途径，但硅在嵌脱锂过程中严重的体积变化使电极的结构和循环稳定性迅速下降。研究结果表明，减小硅反应相尺度到亚微米或纳米程度能改善电极的机械和导电稳定性。该项目拟研究实用性强的电沉积技术制备锂离子电池用微米级厚度硅基薄膜负极，通过与金属共沉积，提高沉积层的导电性，确保薄膜厚度的可控性，同时达到改善电极机械强度的目的。另一方面，将发展独特的电极构造，通过调控电极结构和形貌，抑制硅基电极的体积效应，使电极在高储锂容量条件下保持结构稳定。在此基础上，进一步发展与硅基电极相适应的电解质体系，有效提高电极电化学嵌脱锂可逆性，为锂离子电池的新发展奠定基础。