CoO2
Cobalt dioxide · Cobalt(IV) oxide
Cobalt dioxide is an inorganic compound that typically exists as a layered oxide structure. It is primarily studied for its role as a cathode material in advanced electrochemical energy storage systems.
Overview
Key Properties
Cross-validated computational properties for Cobalt dioxide, 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.
0.01–1.25 eV
Range across DFT structures
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.
0.000 eV/atom
Best (lowest) across sources
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.
On hull (stable)
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
363
5 databases, 43 space groups
Validation
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of CoO2. 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.
1.00 / 1.00
Trust tier: medium
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
0.000 eV
EAH spread across sources
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
2
jarvis, materials_project
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
All match
Crystallography
Reported Structures
Lowest-energy structures reported for CoO2, 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. |
|---|---|---|---|---|---|
| I4/m (No. 87) | tetragonal | 0.59 | 0.0000 | -6.749 | 4.85 |
| Aem2 (No. 39) | orthorhombic | 1.13 | 0.0058 | -6.743 | 4.09 |
| R-3m (No. 166) | trigonal | 0.00 | 0.0067 | -6.742 | 2.70 |
| P-1 (No. 2) | triclinic | 0.84 | 0.0125 | -6.736 | 4.47 |
| C2/m (No. 12) | monoclinic | 1.25 | 0.0142 | -6.735 | 4.47 |
| Pnma (No. 62) | orthorhombic | 0.01 | 0.0253 | -6.724 | 5.11 |
| C2 (No. 5) | monoclinic | 0.00 | 0.0259 | -6.723 | 4.49 |
| I41/amd (No. 141) | tetragonal | 0.94 | 0.0573 | -6.692 | 4.76 |
| P63mc (No. 186) | hexagonal | 0.00 | 0.0678 | -6.681 | 5.18 |
| C2/c (No. 15) | monoclinic | 1.03 | 0.0732 | -6.676 | 2.92 |
| P3m1 (No. 156) | trigonal | 0.00 | 0.0834 | -6.665 | 4.67 |
| R-3m (No. 166) | trigonal | 0.00 | 0.0887 | -6.660 | 4.96 |
Uses
Applications
Where Cobalt dioxide is used.
Lithium-ion battery researchElectrochemical energy storageCatalysis research
Reference
Frequently Asked Questions
Common questions about Cobalt dioxide, answered from cross-validated data.
What is CoO2?
Cobalt dioxide is an inorganic compound that typically exists as a layered oxide structure. It is primarily studied for its role as a cathode material in advanced electrochemical energy storage systems.
More questions
What is CoO2 used for?
Cobalt dioxide (CoO2) is used in lithium-ion battery research, electrochemical energy storage, and catalysis research.
What is the band gap of CoO2?
Cobalt dioxide (CoO2) has a DFT-computed band gap of 0.01–1.25 eV across 363 reported structures.
Is CoO2 a metal, semiconductor, or insulator?
With a band gap up to 1.25 eV it is a semiconductor.
Is CoO2 thermodynamically stable?
Yes — Cobalt dioxide (CoO2) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
What is the crystal structure of CoO2?
The lowest-energy reported polymorph of Cobalt dioxide (CoO2) is tetragonal symmetry, space group I4/m (No. 87).
What is the density of CoO2?
The computed density of the ground-state structure of Cobalt dioxide (CoO2) is 4.85 g/cm³.
How many polymorphs of CoO2 are known?
363 structures of CoO2 are reported across 5 databases, spanning 43 distinct space groups.
What elements does CoO2 contain?
Cobalt dioxide (CoO2) contains Co and O (2 elements).
Where does the data for CoO2 come from?
CoO2 data is cross-referenced from materials_project.
Explore
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).
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