Replication Data for: Tailoring Li-Al-O Interphases in Garnet-Type Solid-State Electrolytes via Powder Atomic Layer Deposition

Study Overview In this study, the influence of atomic layer deposition (ALD) derived Li-Al-O interphases in garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZTO) solid-state electrolyte (SSE) was investigated. Garnet-type SSE are prone to lithium dendrite growth along interfaces, which causes short-circuits, significantly reducing cell performance. ALD offers high control over coating chemistry and morphology to precisly modify these interfaces in SSEs. Here, Al2O3 ALD coatings were applied on LLZTO powder. MAS NMR, XPS and STEM analysis reveal the formation of a compositionally graded Li-Al-O interphase upon deposition due to proton-exchange-induced lithium diffusion. During high-temperature sintering, the ALD coating induces densification and considerable interdiffusion with LLZTO, resulting in a multi-phase microstructure which can be directly controlled via the ALD process, as confirmed by XRD, SEM and EDS measurments. Electrochemical testing reveals that medium-thickness coatings (~ 6.8 nm, 25 ALD cycles) yield optimal performance, exhibiting ionic conductivity at room temperature of 0.39 mS/cm with good Li-dendrite resitance and long-term cycling stability. Dataset Description This dataset contains NMR, XPS, XRD, Ellipsometry, EDS line scans, and electrochemical measurements to investigate Li-Al-O interphases in LLZTO. The dataset is organized into the following folders: NMR 27Al Solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy experiments were performed using an AvanceNEO spectrometer (Bruker). Data are stored in the folder NMR. XPS X-ray photoelectron spectroscopy (XPS) measurements of the Al 2p and C 1s region were conducted using a NEXSA G2 spectrometer (Thermo Fisher Scientific). Data are stored in the folder XPS. XRD X-ray diffraction (XRD) experiments were recorded using an Empyrean diffractometer (Pananalytical). Quantitative phase analysis (QPA) on the XRD diffractograms were conducted using the software package Diffrac.Topas version 7 (Bruker). The corresponding diffractograms and fitting data are stored in the folder XRD. Ellipsometry Ellipsometry data were recorded using a FS-8 spectroscopic ellipsometer (Film Sense LLC). Data are stored in the folder Ellipsometry. Electrochemistry Electrochemical impedance spectroscopy (EIS), critical current density (CCD) measurements, long-term plating/stripping experiments and chronoamperometry (CA) measurements were performed. Data are stored in the folder Electrochemistry. EDS line profile EDS line profiles were recorded using a FEI Titan G2 80-200 CREWLEY system. Data are stored in the folder EDS_line_profile.