Kwak, Won-Jin Park, Seong-Jin Jung, Hun-Gi Sun, Yang-Kook 2024-01-19T23:03:42Z 2024-01-19T23:03:42Z 2021-09-03 2018-03-26 1614-6832 https://pubs.kist.re.kr/handle/201004/121583 Recently, various approaches for adding redox mediators to electrolytes and introducing protective layers onto Li metal have been suggested to overcome the low energy efficiency and poor cycle life of Li-O-2 batteries. However, the catalytic effect of the redox mediator for oxygen evolution gradually deteriorates during repeated cycling owing to its decomposition at the surfaces of both the oxygen electrode (cathode) and the Li metal electrode (anode). Here, optimized Li-O-2 batteries are designed with a continuously effective redox mediator and a stable protective layer for the Li metal electrode by optimizing the LiBr concentration and introducing a graphene-polydopamine composite layer, respectively. These synergistic modifications lead to a reduction of the charge potential to below 3.4 V and significantly improve the stability and cycle life of Li-O-2 batteries. Consequently, a high energy efficiency of above 80% is maintained over 150 cycles. Herein, it is confirmed that the relationships between all the battery materials should be understood in order to improve the performance of Li-O-2 batteries. English WILEY-V C H VERLAG GMBH LITHIUM-OXYGEN BATTERIES SOLID-STATE CYCLING STABILITY PERFORMANCE ELECTROLYTE LAYER ANODE CATHODE GRAPHENE POLYMER Optimized Concentration of Redox Mediator and Surface Protection of Li Metal for Maintenance of High Energy Efficiency in Li-O-2 Batteries Article 10.1002/aenm.201702258 1 ADVANCED ENERGY MATERIALS, v.8, no.9 ADVANCED ENERGY MATERIALS 8 9 scie scopus 000429318400017 2-s2.0-85038257182 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Energy & Fuels Materials Science Physics Article LITHIUM-OXYGEN BATTERIES SOLID-STATE CYCLING STABILITY PERFORMANCE ELECTROLYTE LAYER ANODE CATHODE GRAPHENE POLYMER lithium metal lithium-oxygen battery protective layer redox mediator