Electrochemical performance of a garnet solid electrolyte based lithium metal battery with interface modification
Electrochemical performance of a garnet solid electrolyte based lithium metal battery with interface modification
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DOI：
10.1039/c8ta07652a
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发表时间：
2018-11-14
影响因子：
11.9
通讯作者：
Murugan, Ramaswamy
中科院分区：
文献类型：
--
作者：
Alexander, George V.;Rosero-Navarro, Nataly Carolina;Murugan, Ramaswamy
石榴石型Li 7 La 3 Zr 2 O 12固体电解质由于其高锂离子电导率（高达10（-3）S cm（-1））和与锂金属接触时的化学稳定性（具有6 V的宽电化学窗口）而成为全固态电池的有希望的候选者。然而，主要由于室温下电极/电解质界面的高电阻，实现仍然是难以捉摸的。尽管已经朝着实现有效的Li金属平行于石榴石固体电解质界面做出了显著的改进，但是由于石榴石固体电解质的刚性形态以及阴极材料的差的导电性和化学不稳定性，平行于石榴石固体电解质界面的阴极是具有挑战性的。本文报道了一种用Li 2SiO 3（LS）作为中间层来降低LiNi0.33Mn0.33Co0.33O2（NMC）和Li6.28La3Zr2Al0.24O12（LLZA）固体电解质之间界面电阻的有效策略。通过SEM、粘附测试和电化学对称电池测量（NMC平行于LS-LLZA-LS平行于NMC）对NMC平行于LS-LLZA界面的研究表明，液相衍生的Li 2SiO 3缓冲层不仅改善了润湿性，而且有助于锂离子传导到活性材料。在此基础上，研制了体相全固态和准固态（在平行于LLZA的Li界面处使用凝胶聚合物电解质）制造具有138 mA h g（-1）的初始放电容量的锂金属电池。（100 ℃）和165 mA h g（-1）（25 ℃）。准固态电池（NMC与LS-LLZA并联，GPE与Li并联）在室温下在100 mA cm（-2）的较高电流密度下在50次循环中显示出87%的容量保持率。
Garnet-type Li7La3Zr2O12 solid electrolyte is a promising candidate for all-solid-state batteries owing to its high lithium ion conductivity (up to 10(-3) S cm(-1)) and chemical stability when in contact with the lithium metal with a wide electrochemical window of 6 V. However, the realization still remains elusive mainly due to the high resistance of the electrode/electrolyte interface at room temperature. Although significant improvements have been made toward accomplishing an effective Li metal parallel to garnet solid electrolyte interface, the cathode parallel to garnet solid electrolyte interface is challenging due to the rigid morphology of the garnet solid electrolyte, and poor conductivity and chemical instability of the cathode materials. Herein we report an effective strategy of lowering the interfacial resistance between LiNi0.33Mn0.33Co0.33O2 (NMC) and Li6.28La3Zr2Al0.24O12 (LLZA) solid electrolytes with a Li2SiO3 (LS) interlayer. The investigation of the NMC parallel to LS-LLZA interface by SEM, adherence test and electrochemical symmetric cell measurement (NMC parallel to LS-LLZA-LS parallel to NMC) revealed that a liquid phase derived Li2SiO3 buffer layer, not only improves the wettability, but also assists the lithium ion conduction to the active material. On the basis of this improved interface, a bulk type all-solid-state and a quasi-solid-state (using a gel polymer electrolyte at the Li parallel to LLZA interface) lithium metal batteries were fabricated with initial discharge capacities of 138 mA h g(-1) (100 degrees C) and 165 mA h g(-1) (25 degrees C) at 10 mA cm(-2) and 100 mA cm(-2) , respectively. The quasi-solid-state battery (NMC parallel to LS-LLZA parallel to GPE parallel to Li) at room temperature displays a capacity retention of 87% over 50 cycles at a higher current density of 100 mA cm(-2).