High lithium ionic conductivity of γ-Li3PO4-type solid electrolytes in Li4GeO4-Li4SiO4-Li3VO4 quasi-ternary system
High lithium ionic conductivity of γ-Li3PO4-type solid electrolytes in Li4GeO4-Li4SiO4-Li3VO4 quasi-ternary system
复制标题
Li4GeO4-Li4SiO4-Li3VO4准三元体系γ-Li3PO4型固体电解质的高锂离子电导率
DOI：
10.1016/j.jssc.2020.121651
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发表时间：
2020
影响因子：
3.3
通讯作者：
Kanno Ryoji
中科院分区：
文献类型：
--
作者：
Zhao Guowei;Suzuki Kota;Seki Tomoaki;Sun Xueying;Hirayama Masaaki;Kanno Ryoji
锂快离子导体是实现高安全、高能量全固态锂电池的理想材料。开发了用于Li 4GeO 4 − Li 4SiO 4-Li 3VO 4三元系的具有γ-Li 3 PO 4型结构的LISICON，并分析了其组成、相形成和离子电导率之间的关系。在298 K时，Li3.55（Ge0.45Si0.10V0.45）O 4的离子电导率为5.8 × 10−5 S cm−1，是迄今为止报道的LISICON中的最高值，活化能为0.37 eV。这是通过双掺杂降低激活能和增加指前因子来实现的。Li 3.55（Ge0.45Si0.10V0.45）O 4的Ge 4+、Si 4+和V5+阳离子占据相同的位置;因此，证实了固溶体的形成。Li3.55（Ge0.45Si0.10V0.45）O 4在全固态电池中作为固体电解质，显示了纯锂离子导体的特征，没有电子传导。这项工作验证了双取代策略有利于组成和结构优化，提供增强的离子导电性能。
Lithium superionic conductors (LISICONs) are promising materials to realize high safety, high energy all-solid-state lithium batteries. LISICONs with a γ-Li3PO4-type structure were developed for use in the Li4GeO4−Li4SiO4–Li3VO4ternary system, and the relationship among their composition, phase formation, and ionic conductivity was analyzed. Ionic conductivity of 5.8 × 10−5S cm−1at 298 K, the highest value among the LISICONs reported to date, was obtained for Li3.55(Ge0.45Si0.10V0.45)O4with a low activation energy of 0.37 eV. This was achieved by reducing the activation energy and increasing the pre-exponential factor through dual doping. The Ge4+, Si4+, and V5+cations of Li3.55(Ge0.45Si0.10V0.45)O4occupied the same site; thus, the solid-solution formation was confirmed. Li3.55(Ge0.45Si0.10V0.45)O4functioned as a solid electrolyte in an all-solid-state cell, indicating the features of a pure lithium ionic conductor without electronic conduction. This work verified that the dual substitution strategy is beneficial for compositional and structural optimization, affording enhanced ion-conducting properties.