| 초록 |
As an alternative to the limited energy density of Li-ion batteries, non-aqueous Li-O2 batteries are considered to be a promising energy storage and conversion system, based in part on their ability to store the large theoretical specific energy density of 3,600 Wh/kg. However, there are critical obstacles which limit the development of their electrochemical properties, such as degradation of the electrolyte, poor cycle stability, and decomposition of carbon. Among them, the decomposition of carbon, which leads to the formation of lithium carbonate (Li2CO3), is considered to be a main cause of poor electrochemical performance. The formation of Li2CO3 is based on the carbon cathode and on electrolytes to form a Li2CO3 layer at the interface between the carbon cathode and the Li2O2. In addition, Li2CO3 decomposes into CO2 gas at the end of charge process. Consequently, preventing the formation of Li2CO3 must be done to enhance the electrochemical properties, which is why conductive oxides are considered as a cathode material. In this study, the composite of amorphous RuO2 as an electrocatalyst and aluminum-doped ZnO (AZO) as a cathode material were combined and developed into a carbon-free cathode material for Li-O2 batteries for the first time. The crystallinity of RuO2 has a strong effect on the catalytic activity in Li-O2 batteries. The amorphous RuO2/AZO carbon-free cathode exhibits a noticeably reduced overpotential as well as an enhanced specific capacity. |
