XPS Characterization for Oxidation States of Perovskite Nanoparticles as Oxygen Reduction Electrocatalysts

Performance of Air Electrode Catalysts in the Presence of Redox Mediators for High-Capacity Li–O2 Batteries

“…Figure shows the changes of overvoltages at the end of each discharge/charge cycle during the tests, and Figure S2 exhibits the discharge/charge behavior in detail. Because it has been reported that N-doped carbon increased the ORR activity, ,, N-doped KBFSs were investigated. N-KBFS­(CA) annealed in N 2 at 1000 °C after cyanamide was loaded on KBFS greatly increased the meso- and macropore volumes, effective sites for Li 2 O 2 accumulation (Table ), and reduced overvoltages while maintaining the cyclability of KBFS (Figures a,b and S2b).…”

“…Because it has been reported that N-doped carbon increased the ORR activity, ,, N-doped KBFSs were investigated. N-KBFS­(CA) annealed in N 2 at 1000 °C after cyanamide was loaded on KBFS greatly increased the meso- and macropore volumes, effective sites for Li 2 O 2 accumulation (Table ), and reduced overvoltages while maintaining the cyclability of KBFS (Figures a,b and S2b). In addition to the increase in the accumulation sites of Li 2 O 2 , the increased ORR activity probably promoted the formation of readily decomposable Li 2 O 2 .…”

“…First, various catalysts, which were reported to show high capacities at low current densities, were investigated at a high current density (0.4 mA cm –2 ) and a high areal capacity (4 mAh cm –2 ) in the presence of RMs using KBFSs with large areal weight and were compared with the pristine KBFS. The chosen catalysts were N-doped KBFSs, which have been reported to increase ORR activity, − sulfide catalysts, which have attracted a lot of attention in recent years, − Co catalysts, which have been reported to have high ORR activity, − and other precious metal catalysts like RuO 2 catalysts, which have been reported to show high performance, − Ir catalysts, ,− and PtCo catalysts. , Then, we tried to clarify the characteristics of the catalysts that showed good performance.…”