The interlaboratory comparability and reproducibility of all-solid-state battery cell cycling performance are poorly understood due to the lack of standardized set-ups and assembly parameters. This study quantifies the extent of this variability by providing commercially sourced battery materials—LiNi_0.6Mn_0.2Co_0.2O₂ for the positive electrode, Li₆PS₅Cl as the solid electrolyte and indium for the negative electrode—to 21 research groups. Each group was asked to use their own cell assembly protocol but follow a specific electrochemical protocol. The results show large variability in assembly and electrochemical performance, including differences in processing pressures, pressing durations and In-to-Li ratios. Despite this, an initial open circuit voltage of 2.5 and 2.7 V vs Li⁺/Li is a good predictor of successful cycling for cells using these electroactive materials. We suggest a set of parameters for reporting all-solid-state battery cycling results and advocate for reporting data in triplicate.

Gadolinium-doped ceria (GDC) nanopowders, prepared using the co-precipitation synthesis method, were applied as a starting material to form ceria-based thin films using the electron-beam technique. The scanning electron microscopy (SEM )analysis of the pressed ceramic pellets’ cross-sectional views showed a dense structure with no visible defects, pores, or cracks. The AC impedance spectroscopy showed an increase in the total ionic conductivity of the ceramic pellets with an increase in the concentration of Gd₂O₃ in GDC. The highest total ionic conductivity was obtained for Gd_0.1Ce_0.9O_2-δ (σ_total is 11 × 10⁻³ S∙cm⁻¹ at 600 °C), with activation energies of 0.85 and 0.67 eV in both the low- and high-temperature ranges, respectively. The results of the X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectrometer (ICP-OES) measurements revealed that the stoichiometry for the evaporated thin films differs, on average, by ~28% compared to the target material. The heat-treatment of the GDC thin films at 600 °C, 700 °C, 800 °C, and 900 °C for 1 h in the air had a minor effect on the surface roughness and the morphology. The results of Raman spectroscopy confirmed the improvement of the crystallinity for the corresponding thin films. The optimum heat-treating temperature for thin films does not exceed 800 °C.

All‐solid‐state batteries (ASSBs) are taking the lead as the next‐generation energy storage systems, mainly to the development of new solid electrolytes with high ionic conductivities (>1 mS·cm ⁻¹ ) at room temperature. However, the robust quantification of the ionic transport of these materials is strongly influenced by sample processing, contacting and cell setups. The aim of this study is to evaluate the robustness of the extracted ionic conductivity of sulfide‐based solid electrolytes using lithium argyrodite (Li ₆ PS ₅ Br) as a model system, with particular attention to the influence of sample processing parameters and measurement conditions. The impact of isostatic and uniaxial processing pressures, contact material, measurement and analyses conditions of electrochemical impedance spectroscopy (EIS) is systematically evaluated employing three different measurement cell setups. The findings underscore the necessity for standardized protocols in characterizing solid electrolytes. By establishing a comprehensive methodology for the evaluation of ionic conductivities, this work aims to facilitate the reliable application of solid electrolytes in ASSBs.