摘要
液态电解质锂离子电池因其潜在的安全性问题,发展新的固态电解质锂离子电池是目前所研究的热点。磷酸铝钛锂(Li_(1.5)Al_(0.5)Ti_(1.5)(PO_(4))_(3),LATP)是一种NASICON型陶瓷材料,由于其空气稳定性和较好的Li^(+)导电性而备受关注。然而,为了达到良好的离子导电性并降低晶界阻抗,LATP需要950℃以上的高温来实现致密化,这对于大规模应用来说耗时且昂贵。本文使用简单的溶液浇铸法,通过将LATP嵌入共聚物PVDF-HFP(聚偏氟乙烯-六氟丙烯)基体,合成新的复合固态电解质膜。在此基础上,以磷酸铁锂(LiFePO_(4))为正极,使用PVDF-HFP/LATP复合固态电解质膜进行电池组装。在室温下,利用X射线衍射仪(X-ray diffractometer,XRD)、扫描电子显微镜(scanning electron microscope,SEM)对不同质量比的固态电解质膜进行物理特性研究,并进行相关电化学测试。结果表明,PVDF-HFP/LATP质量比为5∶1的复合固态电解质膜,其LATP的NASICON型晶体结构得到了很好的保持;制备的聚合物固态电解质膜具有阻燃性;组装的半电池在常温条件下锂离子迁移数达到0.70。全电池在20次充放电循环下,放电比容量保持率为85%。
The development of new lithium-ion batteries with liquid electrolytes is a hot topic of study due to their potential safety issues.Lithium aluminum titanium phosphate(Li_(1.5)Al_(0.5)Ti_(1.5)(PO_(4))_(3),LATP),a NASICON-type ceramic material,is of great interest due to its air stability and better Li^(+)conductivity.However,in order to achieve good ionic conductivity and reduce grain boundary impedance,LATP requires high temperatures above 950℃ for densification,which is time-consuming and expensive for large-scale applications.In this work,a new composite solid electrolyte membrane was synthesized by incorporating LATP into a polyvinylidene fluoride-hexafluoropropylene copolymer(PVDF-HFP)substrate by a simple solution casting method.Based on this,the battery was assembled using a PVDFHFP/LATP composite solid-state electrolyte film with lithium iron phosphate as the positive electrode.The physical properties of the solid-state electrolyte membranes with different mass ratios were investigated by X-ray diffractometer(XRD)and scanning electron microscope(SEM)tests at room temperature,and related electrochemical tests were performed.The results showed that the NASICONtype crystal structure of LATP was well maintained in the composite solid electrolyte membrane with a PVDF-HFP/LATP mass ratio of 5∶1;the prepared polymeric solid electrolyte membrane was flameretardant;the assembled half-cell achieved a lithium ion migration number of 0.70 at room temperature;and the discharge-specific capacity retention rate of the full cell was 85%under 20 charge/discharge cycles.
作者
贠淑宏
史雪利
浑前坤
卢炫安
王玉莹
沈鹏程
梁兴华
YUN Shuhong;SHI Xueli;HUN Qiankun;LU Xuanan;WANG Yuying;SHEN Pengcheng;LIANG Xinghua(Guangxi Key Laboratory of Automobile Component and Vehicle Technology(Guangxi University of Science and Technology),Liuzhou 545616,China)
出处
《广西科技大学学报》
CAS
2024年第4期123-129,共7页
Journal of Guangxi University of Science and Technology
基金
国家自然科学基金项目(52161033)
广西自然科学基金项目(2020GXNSFAA297082)资助。
