| 초록 |
Electrochemical potassium-ion intercalation into carbon-based anode materials (CAMs) is an attractive reaction that can be used as active anode materials for potassium ion batteries (PIBs) from a commercial point of view because well-established CAMs, which led to the commercial success of LIBs. However, potassium-ion intercalation into graphite requires a huge volume expansion of the graphite. In addition, the theoretical capacity of graphite anode for PIBs is considerably lower than that of LIBs. As alternative carbon-based potassium-ion intercalation compounds, we report the multilayered turbostratic graphene nanosheets (T-GNSs) with highly disordered local carbon microstructures which have a reversible potassiation behavior. First-principles calculations based on the density functional theory were performed to investigate the origin of improved potassiation performance in T-GNSs. From the comparison of potassium binding and intercalation energetics between the perfect and defective graphite structures, it is clarified that the defective carbon networks having a strong affinity to the potassium atoms were the origin of solid solution electrochemical potassiation behaviors. |
