In the previous section we have clarified the electronic structure and the energetics of the Li 2 O 2 surface and its mechanism for the delithiation in the recharge process of the LOB. We used a proper functional for the exchange and correlation potential as HSE that corrects the self-interaction error introduced by the standard GGA. In the present section, we proceed to study the effect of Na doping in the OER. As mentioned in the Introduction, Chen and coworkers showed a decrease in the charging overpotencial when Na + ions were dissolved in the electrolyte, doping the formed Li 2 O 2 in the LOB. The explanation of this desired effect was ascribed to the generation of more lithium vacancies in the presence of Na + that supposedly gives rise to metallic states as described by their DFT calculations. These calculations were performed using HSE with α=0.207 for which the obtained insulating band gap of ∼ 4 eV is still lower than the one calculated with α=0.48 and the more accurate formalism GW (∼ 6 eV), indicating that the theoretical metallic states obtained in the presence of lithium vacancies with α=0.207 are an artifact because the self-interaction correction is not completely accomplished.