All-Solid-State Li-Ion Battery Using Li_1.5Al_0.5Ge_1.5(PO₄)₃ As Electrolyte Without Polymer Interfacial Adhesion

Solid-state lithium-ion batteries are promising candidates for energy storage devices that meet the requirements to reduce CO₂ emissions. NASICON-type solid-state electrolytes (SSE) are most promising materials as electrolytes for high-performance lithium ion batteries because of their good stability and high ionic conductivity. In this study, we successfully fabricate NASICON-based Li_1.5Al_0.5Ge_1.5(PO₄)₃ lithium fast-ion conductors through melt-quenching with post-crystallization. The effect of crystallization temperature on the structure of LAGP and their ionic conductivity is systematically studied using Rietveld analysis of Synchrotron X-ray powder diffraction patterns, multinuclear magnetic resonance, and electrochemical analysis, revealing that the mobility of Li ion is dependent on crystallization temperature. The glass-ceramic LAGP annealed at 800 °C for 8 h exhibits the highest conductivity of 0.5 mS cm^-1 at room temperature. Moreover, we report the viability of the prepared LAGP glass-ceramic as a solid electrolyte in Li-ion batteries without polymer adhesion. The cycling of Li/LAGP/LFP all-solid-state cell, provides a stable cycling lifetime of up to 50 cycles. This approach demonstrates that LAGP glass-ceramic can have good contact with the electrodes without interfacial layer and can deliver a reasonable discharge capacity after 50 cycles.