Li2S
Lithium sulfide · Lithium sulphide
Lithium sulfide is a stable, insulating compound widely researched as a key material for high-performance solid-state battery electrolytes.
About Lithium sulfide
Lithium sulfide is a binary compound that functions as a wide-gap insulator. Its status as a thermodynamically stable phase on the convex hull makes it a robust candidate for chemical synthesis and materials engineering applications. Given its structural diversity, it remains a highly scrutinized subject in solid-state chemistry research. The material is primarily valued for its role in energy storage systems. Its electronic properties and inherent stability allow it to serve as a foundational building block for developing next-generation solid-state electrolytes and high-capacity battery architectures.
Key Properties
Cross-validated computational properties for Lithium sulfide, aggregated across 5 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of Li2S. Tight agreement means computed properties can be trusted without re-running calculations.
Agreement ScoreA normalized confidence score summarizing how closely independent DFT databases agree. Higher scores mean tighter cross-source agreement.
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
Reported Structures
Lowest-energy structures reported for Li2S, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| — | — | 3.66 | 0.0000 | -1.443 | — |
| Fm-3m (No. 225) | cubic | 3.45 | 0.0000 | -1.522 | — |
| Fm-3m (No. 225) | cubic | 3.39 | 0.0000 | -4.155 | 1.67 |
| — | — | 3.54 | 0.0019 | -1.441 | — |
| Fm-3m (No. 225) | cubic | 3.50 | 0.0356 | -1.486 | — |
| — | — | 4.14 | 0.0569 | -1.387 | — |
| Pnma (No. 62) | orthorhombic | 3.90 | 0.0615 | -4.094 | 1.79 |
| — | — | 4.03 | 0.0616 | -1.382 | — |
| — | — | 3.05 | 0.0679 | -1.376 | — |
| R3m (No. 160) | trigonal | 1.88 | 0.0751 | -4.080 | 1.65 |
| P1 (No. 1) | triclinic | 1.92 | 0.0820 | -4.073 | 1.65 |
| — | — | 3.66 | 0.0833 | -1.360 | — |
Synthesis Routes
Literature-extracted synthesis procedures targeting Li2S.
Applications
Where Lithium sulfide is used.
Patent Landscape
2 patents reference Li2S or close compositional variants.
| Patent | Title | Assignee | Granted |
|---|---|---|---|
| 10170756 | Li2S batteries having high capacity, high loading, and high coulombic efficiency | — | — |
| 9496545 | Li2S@C-coated lithium metal product, method for the production thereof, and use | — | — |
Frequently Asked Questions
Common questions about Lithium sulfide, answered from cross-validated data.
What is Li2S?
Lithium sulfide is a stable, insulating compound widely researched as a key material for high-performance solid-state battery electrolytes.
What is Li2S used for?
What is the band gap of Li2S?
Is Li2S a metal, semiconductor, or insulator?
Is Li2S thermodynamically stable?
What is the crystal structure of Li2S?
How many polymorphs of Li2S are known?
How is Li2S synthesized?
What elements does Li2S contain?
Where does the data for Li2S come from?
How It Compares
As a fundamental binary sulfide, lithium sulfide serves as a benchmark material for understanding lithium-based ionic conductivity in solid-state systems, providing a stable reference point for the development of more complex multi-component sulfide electrolytes.
Data sources & attribution
- oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)
- jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
- materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
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