Superionic conductivity in lithium argyrodite solid-state electrolyte by controlled Cl-doping
Superionic conductivity in lithium argyrodite solid-state electrolyte by controlled Cl-doping
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DOI：
10.1016/j.nanoen.2019.104396
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发表时间：
2020-03
期刊：
影响因子：
17.6
通讯作者：
Chuang Yu;Yong Li;M. Willans;Yang Zhao;Keegan Adair;Feipeng Zhao;Weihan Li;Sixu Deng;Jianwen Lia
中科院分区：
文献类型：
--
作者：
Chuang Yu;Yong Li;M. Willans;Yang Zhao;Keegan Adair;Feipeng Zhao;Weihan Li;Sixu Deng;Jianwen Lia
通过引入氯来调整结构中的S/氯无序，可以提高锂辉石的锂离子导电性。对于Li5.7PS4.7Cl1.3，获得了高达6.4毫秒/厘米的超快室温锂离子电导率。系统研究了Li7-xPS6-xClx(x=1.0，1.1，1.2，1.3，1.4，1.5，1.6，1.7，1.8，1.9)的合成工艺参数，以获得高离子导电性的纯锂绿泥石相。利用交流阻抗谱和7Li自旋晶格驰豫核磁共振技术研究了Cl2+掺杂对锂离子电导率的影响。从头算分子动力学(AIMD)模拟结果表明，在短扩散和长扩散尺度上，Cl2+的引入都能有效地降低锂离子迁移的势垒。采用LiNbO_3包覆LiNi0.8Mn0.1Co0.1O2正极和Li5.7PS4.7Cl1.3固体电解液的全固态锂电池在较高的电流密度下表现出较高的放电容量和良好的循环性能。交流阻抗谱和恒电流间歇滴定技术(GITT)进一步证实，电化学性能的改善可以归因于电压极化的缓解和阴极与固体电解质之间界面电阻的降低。
The lithium ion conductivity of lithium argyrodite can be improved by introducing Cl to tailor the S/Cl disorder in the structure. An ultrafast room temperature lithium ion conductivity of up to 6.4 mS/cm was achieved for Li5.7PS4.7Cl1.3. The synthesis parameters for Li7-xPS6-xClx(x = 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9) are systematically investigated to obtain pure lithium argyrodite phase with high ionic conductivity. AC impedance spectroscopy and7Li spin-lattice relaxation NMR are utilized to show the enhancement of lithium ion conductivity caused by the incorporation of Cl.Ab initiomolecular dynamics (AIMD) simulations proved that the introduction of Cl can effectively decrease the energy barriers for lithium ion migration in both short and long diffusion length scales. All-solid-state lithium batteries using LiNbO3-coated LiNi0.8Mn0.1Co0.1O2cathode and Li5.7PS4.7Cl1.3solid electrolyte display high discharge capacities and excellent cycling performances at relatively high current densities. EIS and galvanostatic intermittent titration technique (GITT) further confirm that the improved electrochemical performance can be attributed to the mitigation of voltage polarization and reduction of the interfacial resistance between the cathode and solid electrolyte.