(360d) Investigating the Effect of Oxidic Functional Group on Graphene Oxide-Molybdenum Disulfide Heterostructures As Anode for Sodium-Ion Battery

The heterojuctions of layered materials are being massively studied as a potential electrode for a rechargeable sodium-ion battery (SIB). Among them, it is experimentally known that MoS₂/reduced Graphene Oxide (rGO) has higher capacity and lower electric conductivity than MoS₂/Graphene due to the functional groups. However, underlying mechanism for the changes in cell performances depending on functional groups has not yet been clearly identified. In this study, the effect of functional groups on capacity and metallicity is investigate using the first-principles density functional theory computation, which allows to decouple individual influence of a specific functional group. The results indicate that the Na intercalation energy becomes stable in the order of O, COOH, and OH, which implies elevated capacity. However, the electronic structure analysis shows opposite trend for, electrical conductivity. Our study provides guidelines for future development of high-performance electrodes through atomistic level understanding on the relationship between the functional groups in graphene and the functionality of electrode.