LiI가 리튬 공기 전지 구동 성능에 미치는 영향

Abstract

Pairing lithium and oxygen in aprotic solvents can theoretically lead to one of the most promising electrochemical cells available. If successfully run on well, Li-oxygen battery system is able to compete with technologies such as internal combustion engine of commercial vehicle and provide a sufficient energy density that vehicle is required. However, there are many problems that have inhibited this technology from becoming realistic related to solutions and decomposition of carbon electrode(stability of electrode), high overvoltage on charging state, low rate capability, and limited cycle life. One of the strategy to reduce of charge overvoltage and enhance the rate capability is the use of iodide ion as redox mediator for oxidation of Li2O2 rapidly. We investigated LiI as an additive and whole salt of ether base electrolyte. When LiI concentration was high, LiI accelerate a side reaction forming lithium hydroxide as a major product. In addition, the presence of oxygen meke easier the reduction of I3- to I-. When LiI concentration was low, the major product is lithium peroxide like other normal Li-oxygen batteries. Then, I2 formed in charge process acts as a redox mediator for lithium peroxide oxidation.