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Development of new sulfide Li+ superionic conductors with mechanical sinterability is the key to the success of all-solid-state lithium batteries. While phosphorus-containing sulfide superionic conductor materials have been widely investigated, phosphorus-free materials showing good air-stability have been overlooked. Herein, the Li+ dynamics in Sb-substituted Li 4 SnS 4 showing a high Li+ conductivity of max. 0.85 mS cm−1 at 30 °C and excellent dry-air stability as well as negligible H 2 S evolution is described. Structural analysis with X-ray and neutron diffraction reveals that Sb-substitution renders an expansion of the lattice volume and formation of Li vacancies. Additionally, 1D-preferable 3D Li+ diffusion channels in Li 4-x Sn 1-x Sb x S 4 are disclosed. The fast Li+ diffusion in Li 4-x Sn 1-x Sb x S 4 is rationalized by complementary analysis using AC impedance measurements, bond valence energy landscape calculation, and 7Li nuclear magnetic resonance spectroscopy. Excellent electrochemical performances of TiS 2 electrodes employing Li 3.85 Sn 0.85 Sb 0.15 S 4 in all-solid-state batteries are demonstrated. Image 1 • Sb-substituted Li 4 SnS 4 shows a maximum Li+ conductivity of 0.85 mS cm−1 at 30 °C. • Excellent dry-air stability and negligible H 2 S evolution are confirmed. • 1D-preferable 3D Li+ diffusion channels disclosed by neutron diffraction analysis. • Performance of all-solid-state Li-ion batteries using Li 3.85 Sn 0.85 Sb 0.15 S 4. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrochemo-mechanical effects for all-solid-state batteries are categorized. • The mechanical properties of solid electrolytes are considered. • Stress sources, resulting cell failures, and stress cross-talks are discussed. All-solid-state batteries (ASSBs) using inorganic solid electrolytes (SEs) are in the spotlight for next-generation energy storage devices because of their potential for outstanding safety and high energy density. Recent progress in this field has been primarily based on advances in materials, such as the discovery of SEs with high ionic conductivities and the improvement of interfacial stability in electrodes. However, the use of inelastic SEs causes severe electrochemo-mechanical failures, such as cathode active material (CAM) disintegration, CAM/SE contact loss, and stress build-up during cycling, deteriorating the Li+ and e− transport pathways. Although these concerns have been addressed previously, they have not been contextualized systematically in terms of the mechanical interactions among the components and their impacts on electrochemical performance. Here, we categorize the electrochemo-mechanical effect in ASSBs and its ramifications in terms of stress sources, active materials, composite electrodes, and cell stacks. [ABSTRACT FROM AUTHOR]