Starting from published charge/discharge curves and X-ray data on Pmmn-LiFeO2 and LiFe5O8 as cathode materials vs. Li anode, a scheme of electrochemical reactions is proposed to explain the unclear electrode functionality of the 'corrugated layer' LiFeO2 phase. The scheme was validated by quantum-mechanical calculations (CRYSTAL09 code, hybrid B3LYP Hamiltonian) on a number of structural models for Li1-xFeO2, LiFe5O8, and Li3Fe5O8. Magnetic interactions were taken into account, finding antiferromagnetic (Li1-xFeO2) and ferrimagnetic (LiFe5O8 and Li3Fe5O8) orderings as stable states. At variance with spinel-like LiFe5O8, Li3Fe5O8 displays a rocksalt-type superstructure. The computed energies for reactions (I) 4LiFeO(2) --> 4Li(0.75)FeO(2) + Li, (II) 4Li(0.75) FeO2 + Li --> 4/5LiFe(5)O(8) + 8/5Li(2)O, and (III) 1/2LiFe(5)O(8) + Li <-> 1/2Li(3)Fe(5)O(8) are 4.44, -3.62, and -2.10 eV, respectively. Such values compare satisfactorily with the average charge/discharge voltages observed for positive electrodes made up of Pmmn-LiFeO2 and of LiFe5O8. (C) 2010 Elsevier B.V. All rights reserved.