Influence of Surface Area of Mesopore on Discharge Characteristics for Lithium-Air Secondary Battery

Abstract

We prepared the carbon electrodes using the CNovel carbons (CNovel P(2)010, CNovel P(4)050, and CNovel MH) as the new carbon materials and investigated the discharge characteristics of carbon electrodes for lithium-air secondary battery. The discharge tests showed that the CNovel P(2)010 electrode had the highest first discharge capacity (2.116 mAh cm-2). From the relationship between the surface area of mesopores (2-50 nm) and the first discharge capacity, the first discharge capacity increased with increasing the surface area of mesopores. The first discharge capacity was more strongly related to the surface area of mesopores than the mesopore volume. From the electrochemical impedance spectroscopy (EIS), the CNovel P(2)010 electrode showed the lowest charge transfer resistance. It was suggested that an increase in the thickness of Li2O2 layer enhanced the overpotential. It was found that the surface area of mesopores had an influence on the discharge characteristics.