纳米锂镧锆钽氧粉体复合聚氧化乙烯制备的固态电解质电化学性能的研究

发布时间：2018-05-11 19:30

  本文选题：固态电解质 + 聚氧化乙烯　； 参考：《储能科学与技术》2016年05期

【摘要】：与采用液体电解液的传统二次锂离子电池相比,固态二次锂电池在高能量密度和安全性方面具有显著的潜在优势,近年来成为国内外的研究热点。作为固态二次锂电池的核心组成,固态电解质需要具备高离子电导率、宽电化学窗口、对锂稳定、力学性能优以及可抑制锂枝晶等特性。为达到以上要求,本工作探索制备了由纳米钽掺杂锂镧锆氧(LLZTO)粉体与聚氧化乙烯(PEO)复合的有机-无机复合固态电解质膜材料,对比研究了在有机物PEO中添加锂盐和不添加锂盐对固态电解质膜电导率及电化学特性的影响。发现在PEO-LLZTO复合电解质膜中,虽然PEO不导电,但界面处存在的渗流效应可极大提高膜的总电导率,室温离子电导率可达到2×10~(-4) S/cm。这一数值虽然略低于PEO-Li TFSI-LLZTO复合电解质膜(室温条件下电导率为6×10~(-4) S/cm),但无锂盐添加的PEO-LLZTO复合电解质膜表现出较好的电化学稳定性和较强的抑制锂枝晶的能力。将PEO-LLZTO复合电解质膜与Li/LiFePO_4和Li/Li Fe0.15Mn0.85PO4组装成软包电池,在0.1 C、60℃的测试条件下可充分发挥正极材料的容量,并可稳定循环200次以上。
[Abstract]:Compared with conventional lithium-ion batteries with liquid electrolyte, solid-state secondary lithium-ion batteries have significant potential advantages in high energy density and safety, and have become a hot research topic in recent years. As the core component of solid-state secondary lithium battery, solid electrolyte should have high ionic conductivity, wide electrochemical window, stable lithium, excellent mechanical properties and restrain lithium dendrite. In order to meet the above requirements, an organic-inorganic composite solid electrolyte membrane material, composed of tantalum doped lithium zirconium oxide (LLZO) powder and polyvinyl oxide (PEO), was prepared. The effects of lithium salt and no lithium salt on the conductivity and electrochemical characteristics of solid electrolyte membrane were studied. It is found that in the PEO-LLZTO composite electrolyte membrane, although PEO is not conductive, the percolation effect at the interface can greatly improve the total conductivity of the membrane, and the ionic conductivity at room temperature can reach 2 脳 10 ~ (-4) S / cm. Although this value is slightly lower than that of PEO-Li TFSI-LLZTO composite electrolyte membrane (the conductivity is 6 脳 10 ~ (-4) S / cm ~ (-1) at room temperature, the PEO-LLZTO composite electrolyte membrane without lithium salt has good electrochemical stability and strong ability to inhibit lithium dendrite. The PEO-LLZTO composite electrolyte membrane was assembled with Li/LiFePO_4 and Li/Li Fe0.15Mn0.85PO4 to form a soft-clad battery. Under the test condition of 0.1C ~ (10) C ~ (60 鈩，

本文编号：1875291