陶瓷液态混合电解质中锂离子自发交换和协同传导实现高效转移

Lithium-ion spontaneous exchange and synergistic transport in ceramic-liquid hybrid electrolytes for highly efficient lithium-ion transfer

陶瓷电解质被广泛用于构建固液混合电解质,对提升固液混合电池的电化学性能和安全性能具有重要作用.然而,固液混合电解质中锂离子的传输机制尤其是陶瓷电解质对离子输运的贡献尚不清楚.该工作设计了3种陶瓷液态混合电解质,通过固态核磁共振谱追踪锂同位素离子,揭示了固液混合电解质中的离子传输路径.实验结果表明,在陶瓷液态混合电解质中,陶瓷电解质能够和液态电解质同时传导锂离子,并发现陶瓷电解质和液态电解质之间存在自发锂离子交换,进一步促进了固液混合电解质系统中高效的锂离子传导.该工作揭示的固液混合传导机制和模型为固液混合电解质和电池的发展提供了理论基础.

Ceramic electrolytes are important in ceramic-liquid hybrid electrolytes(CLHEs),which can effectively solve the interfacial issues between the electrolyte and electrodes in solid-state batteries and provide a highly efficient Li-ion transfer for solid–liquid Li metal batteries.Understanding the ionic transport mechanisms in CLHEs and the corresponding role of ceramic electrolytes is crucial for a rational design strategy.Herein,the Li-ion transfer in the ceramic electrolytes of CLHEs was confirmed by tracking the 6Li and 7Li substitution behavior through solid-state nuclear magnetic resonance spectroscopy.The ceramic and liquid electrolytes simultaneously participate in Li-ion transport to achieve highly efficient Li-ion transfer in CLHEs.A spontaneous Li-ion exchange was also observed between ceramic and liquid electrolytes,which serves as a bridge that connects the ceramic and liquid electrolytes,thereby greatly strengthening the continuity of Li-ion pathways in CLHEs and improving the kinetics of Li-ion transfer.The importance of an abundant solid–liquid interface for CLHEs was further verified by the enhanced electrochemical performance in LiFePO4/Li and LiNi0.8Co0.1Mn0.1O2/Li batteries from the generated interface.This work provides a clear understanding of the Li-ion transport pathway in CLHEs that serves as a basis to build a universal Li-ion transport model of CLHEs.