锂离子电池玻璃态电解质导电机理的研究进展

Progress of Research on the Conductive Mechanism of the Glassy Electrolytes in Lithium Ion Batteries

锂离子电池玻璃态电解质同晶体型电解质相比较具有导电性各向同性、锂离子电导率高等诸多优点,开发在室温下具有较高的离子电导率及良好的化学、电化学稳定性的玻璃态电解质材料已经成为锂离子电池领域的重要研究方向之一。本文介绍了各种玻璃态电解质体系的导电特性及导电机理,并重点分析与讨论混合网络形成体效应在一些典型玻璃态电解质体系中的微观作用机理。本文还总结了混合网络形成体效应在玻璃态电解质中发生的前提条件,并指出深入研究玻璃态电解质的导电机理对开发出具有优异电化学性能的无机非晶固态电解质体系具有重要的指导意义。

Glassy electrolytes have broad prospects for the application in all solid-state lithium ion batteries since they have isotropic conductivity and higher lithium ionic conductivity compared with ceramic electrolytes. In recent years, numerous groups have attempted to improve the lithium ionic conductivity, chemical and electrochemical stability of glassy electrolytes through nitrogen-incorporation by radio-frequency magnetron sputtering, preparing mixed former glasses and glass-ceramics by special technologies. In present review, conductive characteristics and mechanism in various glassy electrolytes are introduced. The micro-mechanisms of mixed former effect in several typical glassy electrolytes are discussed emphatically. The mixed former effect produces the non-bridge oxygen providing lithium-ion with the vacant place to move into or out, as well as expanding the lithium-ion conduction pathway to enhance ionic mobility in the network. The effect is brought about by the phase separation in micro structure of glassy electrolytes, which can be described as the isolation of continuous Li-rich phase with high ionic conductivity and isolated Li-poor phase with low ionic conductivity in micro structure. Finally, the premise condi- tions of mixed former effect occurring to a ternary glassy are summarized. Further study on conductive mechanisms of glassy electrolytes has important guiding significance for theory in developing glassy electrolytes with good chemical and electrochemical performances.