Fig. 5: Predicted voltage hysteresis of Na2-xMn3O7 with hypothetical peroxide-like O22− dimers.
From: Nonpolarizing oxygen-redox capacity without O-O dimerization in Na2Mn3O7
DFT calculated convex hull and voltage profile of Na2-xMn3O7 with O−• and with O22−. The formation energies of both pristine structures and peroxide phases were calculated relative to pristine Na2Mn3O7 and NaMn3O7 phases. Black and red crosses in the convex hull are formation energies of Na2-xMn3O7 with O−• and with O22−, respectively. Black and red circles are the lowest states at various desodiated states. The black solid line of the voltage profile represents the charge/discharge curves without O22− formation, while the red solid line represents the discharge curve for hypothetical Na2-xMn3O7 with O22−.
