摘要
为了提高聚合物固态电解质在室温下极低的锂离子电导率,解决其与锂金属负极不良副反应问题,并改善电极接触的界面相容性,以聚乙烯亚胺(PEI)为交联剂,将含丰富羧基的聚丙烯酸(PAA)引入聚偏二氟乙烯-六氟丙烯(PVDF-HFP)中,并添加Li_(1.5)Al_(0.5)Ge_(1.5)(PO_(4))_(3)(LAGP)作为无机填料,采用溶液浇铸法制备PVDF-HFP基固态电解质,对该固态电解质的微观结构进行了表征,并组装对称电池、全电池进行测试。结果表明:所制备的PVDF-HFP基固态电解质各组分相容性好,表面平整,结晶度低;得益于聚合物基团与LAGP活性位点对锂离子的有效促进,室温下锂离子电导率显著提高,达到7.02×10^(-4)S/cm;PAA与锂金属的相互作用有效稳定了界面,Li‖PAG‖Li电池实现了在室温0.5 mA/cm^(2)的高电流密度条件下长达700 h的超长循环寿命;在全电池测试中,以0.5 C的充放电倍率进行100圈循环后,电池仍保持了153.9 mAh/g的放电比容量,容量保持率高达98.4%。该研究制备的PVDF-HFP基固态电解质与锂金属阳极的相容性得到有效提高,界面相容性问题得到改善,为其在实际应用领域的推广提供了实验思路。
To improve the extremely low lithium ion conductivity of polymer solid electrolyte at room temperature and solve the problems of adverse side reactions with lithium metal anode and interface compatibility of electrode contact,polyacrylic acid(PAA)rich in carboxyl groups was introduced into polyvinylidene fluoride hexafluoropropylene(PVDF-HFP)using polyethyleneimine(PEI)as a medium,and Li_(1.5)Al_(0.5)Ge_(1.5)(PO_(4))_(3)(LAGP)was added as an inorganic filler.PVDF-HFP-based solid electrolyte was prepared by solution casting.The microstructure of the solid electrolyte was characterized,and symmetric cells and full cells were assembled for testing.The results show that the prepared PVDF-HFP-based mixed solid electrolyte has good compatibility among the components,a smooth surface and low crystallinity.Thanks to the effective promotion of lithium ions by the polymer groups and LAGP active sites,the lithium ion conductivity at room temperature is significantly improved to 7.02×10^(-4)S/cm.The interaction between PAA and lithium metal effectively stabilizes the interface,and the Lil‖PAG‖Li battery achieves an ultra-long cycle life of up to 700 h at a high current density of O.5 mA/cm^(2) at room temperature.In the full battery test,after 100 cycles at a charge and discharge rate of O.5C,the battery still maintains a discharge specific capacity of 153.9 mAh/g,and the capacity retention rate is as high as 98.4%.The compatibility of the PVDF-HFP-based solid electrolyte prepared in this study with the lithium metal anode is effectively improved,and the interface compatibility problem is improved,providing an experimental idea for its promotion in practical application.
作者
童敏飞
田芳硕
李梦成
叶方敏
TONG Minfei;TIAN Fangshuo;LI Mengcheng;YE Fangmin(School of Science,Zhejiang Sci-Tech University,Hangzhou 310018,China)
出处
《浙江理工大学学报(自然科学版)》
2025年第6期766-773,共8页
Journal of Zhejiang Sci-Tech University(Natural Sciences)
基金
国家自然科学基金项目(22379160)。
