喷雾蒸发法制备Al和Ta掺杂锆酸镧锂固态电解质工艺研究  

Preparation of Al and Ta doped lithium lanthanum zirconate solid electrolyte by spray evaporation

作　　者：高鹏[1] 沈宇帆 张扬[1,2] 张海 刘青[1] GAO Peng;SHEN Yufan;ZHANG Yang;ZHANG Hai;LIU Qing(Department of Energy and Power Engineering,Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Tsinghua University,100084 Beijing,China;Shanxi Research Institute for Clean Energy,Tsinghua University,030000 Taiyuan,China)

机构地区：[1]清华大学能源与动力工程系,热科学与动力工程教育部重点实验室,北京100084 [2]清华大学山西清洁能源研究院,太原030000

出　　处：《煤炭转化》2025年第2期16-23,共8页Coal Conversion

基　　金：国家自然科学基金项目(52176116);华能集团总部科技项目基础能源与科技研究专项项目(HNKJ23-U23YYJC01).

摘　　要：采用喷雾蒸发法制备石榴石型固态电解质锆酸镧锂Li_(7)La_(3)Zr_(2)O_(12)(LLZO),并经过煅烧-烧结得到固态电解质片。喷雾蒸发法合成LLZO具有达到分子级别混合、不会产生大量废水、容易调控合成条件等优势。LLZO常见的高锂离子电导率掺杂相包括Al掺杂LLZO(Li_(6.1)La_(3)Zr_(2)Al_(0.3)O_(12),Al-LLZO)和Ta掺杂LLZO(Li_(6.4)La_(3)Zr_(2)Ta_(0.6)O_(12),Ta-LLZO)。然而,喷雾蒸发法所用的前驱液绝大多数情况下是溶液,因此合成Ta-LLZO存在一定困难,目前还没有用喷雾蒸发法合成Ta-LLZO的相关报道。因此,提出配置含有固态Ta_(2)O_(5)颗粒的悬浊液作为前驱液,进而用喷雾蒸发法合成Ta-LLZO的办法,并采用扫描电子显微镜(SEM)、X射线衍射(XRD)、电化学阻抗谱(EIS)分析等表征测试技术,研究了Al掺杂和Ta掺杂对蒸发粉末和煅烧粉末的形貌及晶体结构以及对最终固态电解质片形貌、晶体结构、电导率的影响规律。结果表明:对于Al掺杂,在高蒸发温度、高浓度前驱液合成条件下,蒸发粉末容易形成球壳结构,反之容易形成实心结构,对于Ta掺杂,固态Ta_(2)O_(5)颗粒的存在使得蒸发粉末容易形成实心结构;Al掺杂的煅烧粉末里含有较多的LaAlO_(3)杂质,而Ta掺杂的煅烧粉末里含有较多的La_(2)Zr_(2)O_(7)杂质;Al掺杂的电解质片的锂离子电导率为2.0×10^(-4) S/cm,Ta掺杂的电解质片的锂离子电导率为2.7×10^(-4) S/cm。In this study,garnet-type solid-state electrolyte lithium lanthanum zirconate(Li_(7)La_(3)Zr_(2)O_(12),LLZO)was prepared using the spray evaporation method,and solid electrolyte pellets were obtained through calcination and sintering.The synthesis of LLZO via spray evaporation offers advantages such as achieving molecular-level mixing,generating minimal wastewater,and ease of controlling synthesis conditions.Common dopants for high lithium-ion conductivity phases of LLZO include Al-doped LLZO(Li_(6.1)La_(3)Zr_(2)Al_(0.3)O_(12),Al-LLZO)and Ta-doped LLZO(Li_(6.4)La_(3)Zr_(2)Ta_(0.6)O_(12),Ta-LLZO).However,since the precursor used in the spray evaporation method is predominantly solution,synthesizing Ta-LLZO presents certain difficulties,and to date,there have been no reports on the synthesis of Ta-LLZO using this method.This paper proposes a method for synthesizing Ta-LLZO by using a suspension containing solid Ta_(2)O_(5) particles as the precursor.Characterization techniques such as scanning electron microscopy(SEM),X-ray diffraction(XRD),and electrochemical impedance spectroscopy(EIS)were employed to investigate the effects of Al and Ta doping on the morphology of evaporation powders,the morphology and crystal structure of calcination powders,as well as the morphology,crystal structure,and ionic conductivity of the final solid electrolyte pellets.The results indicate that for Al doping,under conditions of high evaporation temperature and high precursor concentration,the evaporation powders tend to form a spherical shell structure,while conversely,a solid structure is more likely to form.For Ta doping,the presence of solid Ta_(2)O_(5) particles leads to the formation of a solid structure in the evaporation powders.The calcination powders of Al doped LLZO contain more LaAlO_(3) impurities,while the Ta doped calcination powders contain more La_(2)Zr_(2)O_(7) impurities.Ultimately,the lithium-ion conductivity of the Al doped electrolyte pellets is found to be 2.0×10^(-4) S/cm,and that of the Ta doped electrolyte pe

关 键 词：Al-LLZO Ta-LLZO 喷雾蒸发法 形貌 锂离子电导率 

分 类 号：O6-333[理学—化学]