| 초록 |
Graphene oxide (GO) has been attractive due to its possibility as an energy storage material. Herein, we show that the thermally reduced GO (TrGO) is a good candidate for rechargeable Li-ion batteries (LIBs) and hydrogen storage materials. TrGO was synthesized by a modified Hummers method followed by thermal reduction to remove its functional groups (hydroxyl, epoxy, and carboxyl groups) under a nitrogen atmosphere at variable temperatures (300, 400, 500, and 600 ºC). We have measured high pressure H2 isotherms at 77 K and electrochemical properties as anode materials in LIBs for the four TrGOs. The maximum H2 storage capacity of ~ 5.0 wt% and reversible charge-discharge capacity of 1220 mAh/g at 30 mA/g current density are achieved with TrGO annealed at 400 ºC. This behavior is interpreted by the measurement of surface area, pore size with N2 isotherms at 77K. These results demonstrate that the existence of optimal pore size for hydrogen storage and electrochemical properties of LIBs. |
