船舶锂电池LLZO/聚合物基固态电解质的构筑

尹浩东¹，张少君¹，张振¹，石建强²，王明雨^1*

1.山东交通学院 航运学院，山东 威海  264210；2.上海海事大学 商船学院，上海  201306

摘要：为提高固态锂电池能量存储系统的安全性和体积能量密度，采用高温固相烧结法和溶液浇注法，以石榴石型氧化物固态电解质（典型分子式为Li7La3Zr2O12，LLZO）为无机填料，将聚偏氟乙烯-六氟丙烯（polyvinylidene fluoride-hexafluoropropylene, PVDF-HFP）与聚甲基丙烯酸甲酯（polymethyl methacrylate, PMMA）共混制备复合固态电解质PVDF-HFP/PMMA-LLZO。结果表明：固态电解质PVDF-HFP/PMMA-LLZO降低了聚合物体系的结晶度和抑制锂枝晶的形成，LLZO提供支撑基质有利于提高电解质的机械性能和离子电导率，当LLZO占整体复合固态电解质质量的30%时，PVDF-HFP/PMMA-LLZO中的离子电导率为9.58 μS/cm。加入LLZO有利于提高复合聚合物PVDF-HFP/PMMA的锂离子电导率，提高热稳定性和机械性能。采用PVDF-HFP/PMMA-LLZO与LiFePO4/Li制备固态锂电池，室温下，放电倍率为0.1 C时首次放电比容量为138.96 mAh/g，循环50次后放电比容量保持率为86%，放电倍率为0.2 C时放电比容量为152.7 mAh/g。LLZO/聚合物复合固态电解质的构筑可为船舶固态锂电池的应用提供借鉴与参考。

关键词：船舶锂电池；固态电解质；PVDF-HFP/PMMA-LLZO；放电比容量

Construction of LLZO/polymer based solid electrolyte for marine lithium battery

YIN Haodong¹, ZHANG Shaojun¹, ZHANG Zhen¹,SHI Jianqiang², WANG Mingyu^1*

1.School of Navigation and Shipping, Shandong Jiaotong University, Weihai 264210, China；

2.School of Merchant Navy, Shanghai Maritime University, Shanghai 201306,China

Abstract: In order to improve the security and bulk energy density of the energy storage system of solid state lithium batteries, high temperature solid-phase sintering method and solution pouring method are adopted, and garnet LLZO in solid oxide electrolyte is used as inorganic filler. The composite solid electrolyte PVDF-HFP/PMMA-LLZO is prepared through mixing polyvinylidene fluoride-hexafluoroethylene (PVDF-HFP) and polymethyl methacrylate (PMMA). The results show that the solid electrolyte PVDF-HFP/PMMA-LLZO reduces the crystallinity of the polymer system, and inhibits the formation of lithium dendrites. The supporting matrix provided by LLZO is beneficial to improve the mechanical properties and ionic conductivity of the electrolyte. When the content of LLZO accounts for 30% quality of the overall composite solid electrolyte, the ionic conductivity of PVDF-HFP/PMMA-LLZO is 95.8 μS/cm. The addition of LLZO is beneficial to improve the lithium ion conductivity, thermal stability and mechanical properties of PVDF-HFP/PMMA. The solid-state lithium battery is prepared by PVDF-HFP/PMMA-LLZO and LiFePO4/Li. At room temperature, the first-discharge specific capacity is 138.96 mAh/g when the discharge rate is 0.1 C, and the capacity retention rate is 86% after 50 cycles. When the discharge rate is 0.2 C, the discharge specific capacity is 152.7 mAh/g. The construction of LLZO/polymer composite solid electrolyte can provide reference for the application of Marine solid lithium battery.

Keywords:marine lithium battery; solid electrolyte; PVDF-HFP/PMMA-LLZO; specific discharge capacity