Unraveling the Synergistic Coupling Mechanism of Li+ Transport in an Ionogel-in-Ceramic Hybrid Solid Electrolyte for Rechargeable Lithium Metal Battery

Understanding the ionic transport behaviors in hybrid solid electrolytes (HSEs) is critically important for the practical realization of rechargeable Li-metal batteries (LMBs) with high safety. Herein, it is reported a new solid Ionogel-in-Ceramic electrolyte by using the Li1.3Al0.3Ti1.7(PO4)(3) (LATP) ceramic particles as a framework and Poly(ionic liquid)s-in-Salt (PolyIL-in-Salt) ionogel as an ionic bridge via a simple pressing process. The PolyIL-in-Salt ionogel precursor is designed to improve the chemical compatibility at solid-solid interfaces. Molecular dynamics simulations reveal the roles of salt concentrations on the distribution of co-coordination of PolyIL-in-Salt ionogel. Moreover, the PolyIL-in-Salt ionogel containing co-coordination not only inhibits the parasitic reactions between LATP and Li anode but also provides efficient Li+ conducting pathways. Benefiting from the designed structure, the Ionogel-in-Ceramic HSE exhibits an excellent ionic conductivity of 0.17 mS cm(-1) at 50 degrees C. Meanwhile, the as-formed solid electrolyte enables a long cycle of over 3500 h in Li/Li symmetric cell. Further, all-solid-state lithium metal batteries fabricated on LiFePO4 and high voltage LiCoO2 cathodes deliver 160.0 mAh g(-1), 125.0 mAh g(-1), respectively. This study sheds light on the rational design of solid-state electrolytes with efficient interparticle Li+ conduction, compatible, stable, compact, and durable electrode-electrolyte interfaces.

Automated summary

This study presents a new design of solid Ionogel-in-Ceramic electrolyte for rechargeable Li-metal batteries, demonstrating excellent ionic conductivity and long cycling stability. The molecular dynamics simulations reveal the important roles of salt concentrations and co-coordination in the PolyIL-in-Salt ionogel. The designed structure effectively inhibits parasitic reactions and provides efficient Li+ conducting pathways, leading to promising performance in all-solid-state lithium metal batteries.