Dilithium peroxide

  • Formula: Li2O2
  • Hill system formula: Li2O2
  • CAS registry number: [12031-80-0]
  • Formula weight: 45.881
  • Class: oxide
  • Colour: white
  • Appearance: crystalline solid
  • Melting point: 195°C (decomposes to Li2O)
  • Boiling point:
  • Density: 2310 kg m-3

The following are some synonyms of dilithium peroxide:

  • dilithium peroxide
  • lithium(I) peroxide
  • lithium peroxide

The oxidation number of lithium in dilithium peroxide is 1.


One way to make lithium peroxide is to react lithium metal in liquid ammonia with with contolled amounts of oxygen.

2Li(NH3) + O2 → Li2(O2)

Solid state structure

  • Geometry of lithium: 6 coordinate: octahedral
  • Prototypical structure:
Crystal structure of dilithium peroxide.
Crystal structure of dilithium peroxide.

Element analysis

The table shows element percentages for Li2O2 (dilithium peroxide).

Element %
Li 30.26
O 69.74

Isotope pattern for Li2O2

The chart below shows the calculated isotope pattern for the formula Li2O2 with the most intense ion set to 100%.


The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

  • R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
  • N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
  • F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
  • A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
  • R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
  • A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
  • A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
  • J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
  • D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
  • J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
  • J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

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