物理化学学报2024，Vol.40Issue(3)：46-47,2.DOI:10.3866/PKU.WHXB202305016
纳米石榴石固体电解质粉体在聚合物电解质中的均匀分散
Uniform Garnet Nanoparticle Dispersion in Composite Polymer Electrolytes
摘要
Abstract
Solid-state lithium batteries(SSLBs)have the potential to further boost the energy density of Li-ion batteries and improve their safety by facilitating the use of Li-metal anodes and limiting flammability,respectively.Solid electrolytes,as key SSLB materials,significantly impact battery performance,among which composite polymer/garnet electrolytes are promising materials for manufacturing SSLBs on a large scale,owing to polymer electrolyte processing ease in combination with the thermal stabilities and high ionic conductivities of garnet electrolytes,both of which are beneficial.Uniformly dispersing garnet particles in the polymer matrix is important for ensuring a highly ionically conductive composite polymer electrolyte.However,high nanoparticle surface energies and incompatible organic-inorganic interfaces lead to garnet particle agglomeration in the polymer matrix and a poorly ionically conductive composite electrolyte.With the aim of promoting Li6.4La3Zr1.4Ta0.6O12(LLZTO)particle dispersion in both solvents and polymer matrices,in this study,we introduced the 3-glycidyloxypropyl trimethoxy silane(GPTMS)coupling agent onto the LLZTO surface.A 5-nm-thick GPTMS shell was constructed on each LLZTO nanoparticle by covalently bonding GPTMS molecules on the surface of the nanoparticle.The lipophilic epoxy group in GPTMS enables the uniform dispersion of GPTMS-modified LLZTO nanoparticles(LLZTO@GPTMS)in organic solvents,such as acetonitrile,N-methylpyrrolidone,and N,N-dimethylformamide.Particle-size-distribution experiments reveal that LLZTO-nanoparticle dispersity is positively correlated with solvent polarity.Well-dispersed LLZTO suspensions led to superior polyethylene-oxide-based(PEO-based)composite polymer electrolyte ionic conductivities of 2.31×10-4 S·cm-1 at 30 ℃.Both symmetric lithium batteries and SSLBs that use LiFePO4(LFP)cathodes,lithium-metal anodes,and the optimal PEO:LLZTO@GPTMS electrolyte exhibited prolonged cycling lives.Moreover,the polyethylene separator was homogeneously coated with LLZTO nanoparticles following GPTMS modification.LFP|Li batteries with LLZTO@GPTMS-coated PE separators exhibited better cycling stabilities than those of batteries with unmodified LLZTO/PE.This study demonstrated that GPTMS effectively improves LLZTO-nanoparticle dispersibility in both organic solvents and polymer matrices,which is also instructive for other organic-inorganic composite systems.关键词
固态锂电池/石榴石型电解质/复合固体电解质/硅烷偶联剂/纳米粉体分散Key words
Solid-state Li battery/Garnet electrolyte/Composite solid electrolyte/Silane coupling agent/Nanoparticle dispersion分类
化学化工引用本文复制引用
吕寒梅,陈昕,孙麒富,赵宁,郭向欣..纳米石榴石固体电解质粉体在聚合物电解质中的均匀分散[J].物理化学学报,2024,40(3):46-47,2.基金项目
The project was supported by the Key R&D Program of Shandong Province(2021CXGC010401)and the National Natural Science Foundation of China(U1932205,52002197).山东省重点研发计划(2021CXGC010401)和国家自然科学基金(U1932205,52002197)资助项目 （2021CXGC010401）
