Thermodynamic Evaluation of the Possibility of Lithium Superoxide Production
Report Number: AMRL TR 65-126
Author(s): Snow, Richard H.
Corporate Author(s): IIT Research Institute
Laboratory: Aerospace Medical Research Laboratories
Date of Publication: 1965-08
Pages: 37
Contract: AF 33(615)-2351
DoD Project: 6373
DoD Task: 637302
Identifier: AD0626596
Abstract:
To determine whether lithium superoxide can be produced and whether it is stable enough for use in air regeneration units of manned spacecraft, the free energy of lithium superoxide was calculated from estimated values of the heat of formation, entropy, and heat capacity. The estimates were based on graphical comparison with properties of other oxides. The heat of formation was also determined from calculation of the lattice energy by means of the Born-Haber cycle. The result was -65 kcal. The stability of lithium superoxide was deduced by comparing graphically the free energies of the oxides of lithium. The superoxide is unstable by 15 kcal from 100 to 300K and is even more unstable at higher temperatures. Reasonably high pressure and other effects cannot overcome this instability, even at low temperature. Therefore the use of lithium superoxide for air regeneration units is not promising.
Provenance: RAF Centre of Aviation Medicine
Author(s): Snow, Richard H.
Corporate Author(s): IIT Research Institute
Laboratory: Aerospace Medical Research Laboratories
Date of Publication: 1965-08
Pages: 37
Contract: AF 33(615)-2351
DoD Project: 6373
DoD Task: 637302
Identifier: AD0626596
Abstract:
To determine whether lithium superoxide can be produced and whether it is stable enough for use in air regeneration units of manned spacecraft, the free energy of lithium superoxide was calculated from estimated values of the heat of formation, entropy, and heat capacity. The estimates were based on graphical comparison with properties of other oxides. The heat of formation was also determined from calculation of the lattice energy by means of the Born-Haber cycle. The result was -65 kcal. The stability of lithium superoxide was deduced by comparing graphically the free energies of the oxides of lithium. The superoxide is unstable by 15 kcal from 100 to 300K and is even more unstable at higher temperatures. Reasonably high pressure and other effects cannot overcome this instability, even at low temperature. Therefore the use of lithium superoxide for air regeneration units is not promising.
Provenance: RAF Centre of Aviation Medicine