Cu2O
cuprous oxide · copper(I) oxide
Cuprous oxide is a stable semiconducting copper-based oxide used primarily as an anode material in electrochemical energy storage research.
About cuprous oxide
Cuprous oxide is a semiconducting transition metal oxide that maintains high thermodynamic stability as a member of the conversion oxide anode class. Its ability to undergo reversible conversion reactions makes it a significant candidate for advanced electrochemical energy storage systems. Beyond its role in batteries, this material is valued for its distinct electronic properties and structural versatility. With numerous reported crystalline structures, it serves as a foundational building block for developing next-generation anode architectures in high-performance devices.
Key Properties
Cross-validated computational properties for cuprous oxide, aggregated across 3 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.
Reported Structures
Lowest-energy structures reported for Cu2O, 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. |
|---|---|---|---|---|---|
| Pn-3m (No. 224) | cubic | 0.51 | 0.0000 | -5.027 | 6.20 |
| C2/m (No. 12) | Monoclinic | — | — | — | 6.54 |
| P3m1 (No. 156) | Trigonal | — | — | — | 7.09 |
| P3m1 (No. 156) | Trigonal | — | — | — | 7.07 |
| P1 (No. 1) | Triclinic | — | — | — | 5.54 |
| Pnnm (No. 58) | Orthorhombic | — | — | — | 6.26 |
| P21/c (No. 14) | Monoclinic | — | — | — | 6.70 |
| P-1 (No. 2) | Triclinic | — | — | — | 4.08 |
| P-1 (No. 2) | Triclinic | — | — | — | 4.92 |
| P-1 (No. 2) | Triclinic | — | — | — | 9.41 |
| Pm (No. 6) | Monoclinic | — | — | — | 3.45 |
| Cm (No. 8) | Monoclinic | — | — | — | 6.38 |
Applications
Where cuprous oxide is used.
Frequently Asked Questions
Common questions about cuprous oxide, answered from cross-validated data.
What is Cu2O?
Cuprous oxide is a stable semiconducting copper-based oxide used primarily as an anode material in electrochemical energy storage research.
What is Cu2O used for?
What is the band gap of Cu2O?
Is Cu2O a metal, semiconductor, or insulator?
Is Cu2O thermodynamically stable?
What is the crystal structure of Cu2O?
What is the density of Cu2O?
How many polymorphs of Cu2O are known?
What elements does Cu2O contain?
Where does the data for Cu2O come from?
How It Compares
Within the conversion oxide anodes class.
Within the family of conversion oxide anodes, Cu2O is distinguished by its unique oxidation state compared to its sibling CuO, which features a higher copper valence. While many conversion oxides like Fe2O3 or MnO2 rely on complex multi-step redox pathways, Cu2O offers a streamlined electrochemical profile that remains a focal point for researchers aiming to optimize capacity and cycling longevity in battery technologies.
Related Compounds
Other Conversion Oxide Anodes in the database.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
- jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).
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