ZIF-8复合PEO基固态电解质的制备与改性研究  

Preparation and modification of ZIF-8 composite PEO based solid electrolyte

作　　者：黄渭彬 张彪 范金成 杨伟[1] 邹汉波[1] 陈胜洲[1] HUANG Weibin;ZHANG Biao;FAN Jincheng;YANG Wei;ZOU Hanbo;CHEN Shengzhou(College of Chemistry and Chemical Engineering,Guangzhou University,Guangzhou 510006,Guangdong,China)

机构地区：[1]广州大学化学化工学院,广东广州510006

出　　处：《储能科学与技术》2023年第4期1083-1092,共10页Energy Storage Science and Technology

基　　金：国家自然科学基金项目(21776051);广东省自然科学基金项目(2022A1515011715)。

摘　　要：在聚环氧乙烷(PEO)基固体聚合物电解质中加入无机填料,是一种低成本、有效改善其力学和电化学性能的方法。为了更有效地改善PEO基固态电解质的电化学性能,本工作采用流延法制备了纳米沸石咪唑骨架材料(ZIF-8)与聚氧化乙烯(PEO)复合的固态电解质。通过扫描电子显微镜(SEM)、X射线衍射(XRD)等物理表征和电化学阻抗谱(EIS)、伏安线性扫描(LSV)、充放电循环等电化学测试手段,证明了加入20%ZIF-8纳米粒子的PEO基复合固态电解质CPE20具有最小的体电阻、较宽的电化学稳定窗口与最低的活化能(8.4×10^(-3)eV);20℃时,其电导率达到了4.9×10^(-5)S/cm(比纯PEO高一个数量级);70℃时,其电导率为1.08×10^(-3)S/cm(与液态电解液相当);CPE20的锂离子迁移数提高至0.46,而纯PEO基固态电解质为0.36;采用CPE20制备的LiFePO_(4)||Li电池在室温下具有良好的容量和循环性能,而且容量保持率超过96%。加入适量的惰性填料ZIF-8时,可以有效降低聚合物的结晶度,增加聚合物的非晶区,促进锂盐的溶解,提高锂离子的迁移率,使复合固态电解质具有更加优异的电化学性能。因此添加ZIF-8的PEO基固相聚合物在固态金属锂电池中具有广阔的应用前景。Incorporating inorganic fillers into polyethylene oxide(PEO)-based solid polymer electrolytes is a low-cost and effective method to improve their mechanical and electrochemical properties.The solid electrolyte composite of zeolite imidazole skeleton material(ZIF-8)and PEO was prepared using flow-casting method to effectively improve the electrochemical performance of the PEO solid electrolyte.Physical characterizations of scanning electron microscopy,X-ray diffraction,and electrochemical measurement methods,such as electrochemical impedance spectroscopy,linear sweep voltammetry,and chargedischarge cycle,proved that the PEO-based composite solid electrolyte CPE20 with 20%ZIF-8 nanoparticles had the lowest resistance,a broader electrochemical stability window,and an activation energy of 8.4×10^(−3)eV.At 20℃,the conductivity of CPE20 reached 4.9×10^(−5)S/cm,which is one order of magnitude higher than that of pure PEO.When the temperature was increased to 70℃,the conductivity reached 1.08×10^(−3)S/cm.The number of lithium-ion transference of CPE20 increased to 0.46,while that of pure PEO solid electrolyte is 0.36.Thus,the CPE20 preparation of LiFePO_(4)||Li battery has good capacity and cycle performance at room temperature,with a capacity rate of more than 96%.Therefore,adding an appropriate amount of ZIF-8 inert filler can effectively reduce the crystallinity and increase the amorphous zone of the polymer.It can also promote the dissolution of lithium salts and improve the mobility of lithium ions,which make the composite solid electrolyte has more excellent electrochemical performance.Thus,the findings show that the PEO-based solid polymer electrolytes with ZIF-8 have potential application in solid-state lithium batteries.

关 键 词：电化学储能 电解质 聚氧化乙烯 沸石咪唑骨架材料 

分 类 号：TQ152[化学工程—电化学工业]