초록 |
Energy conversion and storage materials that can replace fossil fuels have received considerable attention as growing concerns about global warming. Although lithium ion rechargeable batteries are dominant the mobile devices and electric vehicles in the present, there are still some limitations in terms of cost and lithium reserves in the world. In that sense, Na-based electrode materials have been widely studied due to the abundance and low cost of sodium. Rechargeable sodium batteries, however, have serious safety issues by using flammable organic electrolytes and active sodium metal as an anode material. In order to overcome these drawbacks, the interests of aqueous sodium ion batteries which can solve both shortage of cation sources and safety issues have increased. In this study, the NaTi2(PO4)3/reduced graphene oxide composite has been prepared by a combined two-step synthetic route with chemical method of graphene oxide and solid state reaction. The electrochemical characterizations of NaTi2(PO4)3/reduced graphene oxide composite have been carried out in both nonaqueous and aqueous electrolytes. Cyclic voltammograms, galvanostatic charge/discharge tests indicate that Na ions can be reversibly de/inserted into the NaTi2(PO4)3/reduced graphene oxide composite. High rate performance and cycleability also suggest this composite as a promising anode candidate for rechargeable aqueous sodium ion batteries. |