Probing Alkaline-Earth-Doped Garnet-Type Li7La2.75A0.25Zr1.75M0.25O12 (A = Ca, Sr, Ba; M = Nb, Ta) Electrolytes for All-Solid-State Li Metal Batteries

• DOI: 10.1021/acs.chemmater.3c02615
• Publication Date: 2024-03-05T13:17:45Z
• Authors: Subhajit Sarkar; Cleis Santos; Jens Glenneberg; Ingo Bardenhagen; Julian Schwenzel; Venkataraman Than...
• Keywords: Alkaline earth metal

Solid (ceramic) electrolytes have demonstrated great potential for all-solid-state lithium metal batteries (ASSLMBs), providing better safety and stability over organic liquid electrolyte-based Li-ion batteries. A proper selection of solid an analysis their compatibility with Li are critical improving battery performance. Here, we present extensive experimental study realizing the effect substituting alkaline-earth-metal-doped Li7La2.75A0.25Zr1.75M0.25O12 (A = Ca, Sr, Ba; M Nb, Ta) garnet-type on ionic electronic conductivity, migration pathways, microstructures, electrochemical properties. We examined relationship between bulk surface properties garnet using X-ray photoelectron spectroscopy impedance spectroscopy. Among all garnets studied, Ba Ta codoped Li7La2.75Ba0.25Zr1.75Ta0.25O12 showed chemical against area specific resistance (ASR) ∼33 Ω cm2 a current density 0.5 mA cm–2 at 25 °C without any coating. At −30 50 °C, cell can cycle up to times almost negligible voltage fluctuations. This work illustrates that doping could trigger ion-/electron-transport improve structure ASSLMBs.