LiO2

lithium superoxide

Lithium superoxide is a metastable, semimetallic lithium oxide that acts as a key intermediate in lithium-oxygen battery chemistry.

Crystal structure of LiO2 (orthorhombic, Pnnm (No. 58))
Ground-state structure · Materials Project
Overview

About lithium superoxide

Lithium superoxide is a reactive, metastable member of the lithium oxide family. Its electronic structure is characterized as near-zero-gap, placing it in a semimetallic regime that distinguishes it from the insulating nature of many other binary lithium oxides.

This compound is primarily significant as a transient species in the electrochemical pathways of lithium-air batteries. Because it is not thermodynamically stable, it is highly sought after for research into reaction kinetics and the stabilization of discharge products in energy storage technologies.

At a glance

Key Properties

Cross-validated computational properties for lithium superoxide, aggregated across 3 databases.

Band Gap

0.07 eV
Range across DFT structures

Energy Above Hull

0.083 eV/atom
Best (lowest) across sources

Stability

Metastable
2 DFT sources

Structures

213
3 databases, 27 space groups
Crystallography

Reported Structures

Lowest-energy structures reported for LiO2, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
Pnnm (No. 58)orthorhombic0.000.0831-4.9782.24
C2/m (No. 12)monoclinic0.000.3169-4.7442.35
R-3m (No. 166)trigonal0.070.5915-4.4692.24
Fm-3m (No. 225)cubic0.000.6860-4.3752.60
P-6m2 (No. 187)Hexagonal1.68
P21 (No. 4)Monoclinic2.41
C2/m (No. 12)Monoclinic1.27
C2/m (No. 12)Monoclinic1.35
C2/m (No. 12)Monoclinic1.61
P-1 (No. 2)Triclinic1.97
P-1 (No. 2)Triclinic2.21
P-1 (No. 2)Triclinic2.46
Uses

Applications

Where lithium superoxide is used.

Lithium-air battery researchElectrochemical energy storage studies
Reference

Frequently Asked Questions

Common questions about lithium superoxide, answered from cross-validated data.

What is LiO2?

Lithium superoxide is a metastable, semimetallic lithium oxide that acts as a key intermediate in lithium-oxygen battery chemistry.

More questions
What is LiO2 used for?
lithium superoxide (LiO2) is used in lithium-air battery research and electrochemical energy storage studies.
What is the band gap of LiO2?
lithium superoxide (LiO2) has a DFT-computed band gap of 0.07 eV across 213 reported structures.
Is LiO2 a metal, semiconductor, or insulator?
With a near-zero band gap it behaves as a (semi)metal.
Is LiO2 thermodynamically stable?
lithium superoxide (LiO2) has a lowest energy above hull of 0.083 eV/atom (metastable).
What is the crystal structure of LiO2?
The lowest-energy reported polymorph of lithium superoxide (LiO2) is orthorhombic symmetry, space group Pnnm (No. 58).
What is the density of LiO2?
The computed density of the ground-state structure of lithium superoxide (LiO2) is 2.24 g/cm³.
How many polymorphs of LiO2 are known?
213 structures of LiO2 are reported across 3 databases, spanning 27 distinct space groups.
What elements does LiO2 contain?
lithium superoxide (LiO2) contains Li and O (2 elements).
Where does the data for LiO2 come from?
LiO2 data is cross-referenced from materials_project, mpaloe.
Comparison

How It Compares

Within the lithium oxides class.

Unlike the highly stable Li2O or the robust, commercially established cathode materials like LiCoO2 and LiMn2O4, LiO2 exists as a fleeting and metastable phase. While its siblings in the lithium oxide class are typically utilized as structural components or stable electrodes, LiO2 is studied for its role as a reactive intermediate that dictates the efficiency and cycle life of next-generation power cells.

Explore

Related Compounds

Other Lithium Oxides 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.

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