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.