| 초록 |
Reactive oxygen species or superoxide (O2-) to damage biological cells is generated during metabolic pathways using oxygen as an electron acceptor in biological systems. Superoxide dismutase (SOD) protects cells from the superoxide-triggered apoptosis by converting superoxide to oxygen and peroxide. Lithium-oxygen battery (LOB) cells have the same aging problems caused by superoxide-triggered side reactions. We transplanted the function of SOD of biological systems into LOB cells. A series of organic and inorganic molecules to mimic the function of SOD (shortly, SOD mimics or SODm) were used as superoxide disproportionation chemo-catalysts. As expected, the SODm's as the superoxide scavenger improved capacity retention along charge/discharge cycles successfully. Experimentally observed toroidal morphology of the final discharge product of oxygen reduction (Li2O2) and density functional theory calculation confirmed that the solution mechanism of Li2O2 formation, more beneficial than the surface mechanism from the capacity-gain standpoint, was preferred in the presence of SODm. |
