용융염을 이용한 고전력 밀도 Li-CO2 배터리 연구

Abstract

With recently increasing interest in metal-gas batteries, the Li-carbond dioxide (CO2) cell has attracted considerable attention because of its extraordinary CO2 capture ability during the discharge process and its potential application as a power source for Mars exploration. However, owing to the stable Li2CO3 discharge product, the cell enables operation only at low current densities, which significantly limits the application of Li-CO2 batteries and effective CO2 capture cells. Here, we investigate a high-performance Li-CO2 cell using a quinary molten salt electrolyte (15 mol% LiNO3, 30 mol% KNO3, 30 mol% CsNO3, 10 mol% NaNO3, and 15 mol% Ca(NO3)2) and Ru nanoparticles on the carbon cathode. The nitrate-based molten salt electrolyte allows us to observe the enhanced CO2 capture rate and the reduced discharge-charge over-potential gap with that of conventional Li-CO2 cells. Furthermore, owing to the Ru catalyst, the cell sustains its performance over more than 300 cycles at a current density of 10.0 A g＆minus;1 and exhibits a peak power density of 33.4 mW cm＆minus;2.