MATERIALS DESIGN OF CRYSTALLINE LITHIUM IONIC CONDUCTORS WITH FRAMEWORK STRUCTURE

框架结构晶体锂离子导体材料设计

• 批准号: 09650906
• 负责人: KANNO Ryoji
• 金额: $ 2.11万
• 依托单位: KOBE UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650906/
• 关键词: Lithium ion conductor; Thio-LISICON; Solid electrolyte; リチウムイオン導伝体; 個体電解質; チオリウコン

Lithium superionic conductors exhibit high lithium-ionic diffusion in one of their ionic sublattice - the mobile ion sublattice - at temperature well below melting points. It is of great interest to understand their fast-ionic transport in "solid' materials, which is widely recognized, although still relatively rare, phenomenon. They are also of technological importance for future applications as solid electrolyte for all-solid lithium battery and may solve the safety problems of the rechargeable lithium ion battery using non-aqueous liquid electrolytes.Ceramic crystalline electrolytes have advantages over liquid, polymer, gel or even glass electrolytes for their chemical and electrochemical stability. Many attempts to synthesize new ceramic lithium superionic conductors have been made ; the highest conductivity of 10^<-3> S cm^<-1> was previously reported for H-doped Li_3N.However, the low decomposition potential of 0.445V restricts its application as a lithium solid electrolyte. The new thio-LISICON (LIthium SuperIonic CONductor) found in the Li_2S-GeS_2, Li_2S-GeS_2-ZnS, and Li_2S-GeS_2-Ga_2S_3 systems have structures related to the gamma-Li_3PO_4-type. Six new materials were found (Li_2GeS_3, Li_4GeS_4, Li_2ZnGeS_4, Li_<4-x>Zn_xGeS_4, Li_5GaS_4, and Li_<4+x+delta>(Ge_<1-delta'-x>GaS_x)SS_4), and LiS_<4+x+delta>(GeS_3GaS_x)S_4 showed the highest conductivity of 6.5x10^<-5> S cm^<-1> at room temperature. Our results on electrochemical measurements indicated that LiS_<4+x+delta>(Ge_<1-delta'-x>Ga_x)S_4 is stable up to 5V vs. Li.

锂超离子导体在远低于熔点的温度下在它们的离子亚晶格之一-移动的离子亚晶格中表现出高锂离子扩散。了解它们在“固体”材料中的快离子输运是非常有趣的，这是一种被广泛认可的现象，尽管仍然相对罕见。陶瓷晶体电解质的化学和电化学稳定性优于液体、聚合物、凝胶甚至玻璃电解质。人们尝试合成新的陶瓷锂快离子导体，掺氢Li_3N的最高电导率为10^<-3>S cm ~ 2<-1>，但其分解电位低（0.445V）限制了其作为锂固体电解质的应用。在Li_2S-GeS_2、Li_2S-GeS_2-ZnS和Li_2S-GeS_2-Ga_2S_3体系中发现了新的硫代锂超离子导体（LISICON），其结构与γ-Li_3 PO_4型有关。发现了六种新材料（Li_2GeS_3，Li_4GeS_4，Li_2ZnGeS_4，Li_ Zn_xGeS_4<4-x>，Li_5GaS_4和Li_（4+x+ δ）（Ge_（1-δ '-x）GaS_x）S_4），其中LiS_（4+x+ δ）（GeS_3GaS_x）S_4在室温下具有最高的电导率，为6.5 × 10 ~（10）<-5>S·cm ~<-1>（-1）。电化学测试结果表明，LiS_4+x+ δ&gt;（Ge_1-δ '-x&gt;Ga_x）S_4在5V以下是稳定的。