【摘要】 目前,应用最为广泛的能源储存设备当属以液态电解质为主的商业化锂离子电池,但随着对于高能量、高密度锂离子电池的开发,较为迫切的便是如何提升其安全性能,而解决办法便是用固态电解质替换液态电解质。聚合物类型固态电解质拥有许多优点,如机械性能强、与电极接触良好等,但低的离子电导率一直是限制其发展的最主要因素。本文主要研究了如何利用原子层沉积（atomic layer deposition,ALD）在二氧化钛纳米颗粒上包覆一层Li₃PO₄电解质,而后将其掺杂进聚合物电解质中,制备出高离子电导率复合固态电解质。本文利用透射电子显微镜（TEM）、扫描电子显微镜（SEM）、X射线衍射仪（XRD）等表征手段对该复合电解质的结构进行了表征。利用交流阻抗谱图（AC impedance spectroscopy）测试其阻抗性能,及其离子电导率的变化。最终发现离子导电性能提高的原因是聚合物电解质结晶度的下降及Li₃PO₄电解质包覆层的耦合作用。更多还原

【Abstract】 At present,the most widely used energy storage device is the liquid electrolyte-based commercial lithium-ion battery.However,with the development of high-energy and high-density lithium-ion batteries,it is more urgent to improve their safety performance. The solution is to replace the liquid electrolyte with solid electrolyte. Polymer type solid electrolyte has many advantages,such as strong mechanical properties,good contact with the electrode,etc.,but the low ionic conductivity significantlylimits its development. This paper mainly studies how to use atomic layer deposition to coat the TiO₂ nanoparticles with a layer of Li₃PO₄ electrolyte,and then doped into the polymer electrolyte to prepare the high ionic conductivity composite solid electrolyte. This paper further characterized the structure of the composite electrolyte by means of transmission electron microscopy（ TEM）,scanning electron microscopy（ SEM） and X-ray diffraction（ XRD） and so on. Impedance performance and its ionic conductivity were measured by AC impedance spectroscopy. Finally,we found that the reason for the improvement of the ionic conductivity is the decrease of the crystallinity of the polymer electrolyte and the coupling effect of the Li₃PO₄ electrolyte coating.更多还原