دانلود رایگان مقاله سنتز نانوبلورهای Li3V2(PO4)3 و هدایت پلیمر PEDOT

Abstract

Monoclinic Li3V2(PO4)3 compound is gathering significant interest as cathode material for lithium-ion batteries at the moment because of its high theoretical capacity, good safety and low cost. However, it suffers from bad rate capability and short cycling performance duo to the intrinsic low electronic conductivity. Herein, we report a design of Li3V2(PO4)3 particles coated by conducting polymer PEDOT through a facile method. When the cell is tested between 3.0 and 4.3 V, the core-shell Li3V2(PO4)3@PEDOT electrode delivers a capacity of 128.5 mAh g−1 at 0.1C which is about 96.6% of the theoretical capacity. At a high rate of 8C, it can still maintain a capacity of 108.6 mAh g−1 for over 15 cycles with capacity decay rate of only 0.049% per cycle. The impressive electrochemical performance could be attributed to the coated PEDOT layer which can provide a fast electronic connection. Therefore, it can be make a conclusion that the core-shell Li3V2(PO4)3@PEDOT composite is a promising cathode material for next-generation lithium-ion batteries.

4. Conclusions

In summary, the conducting polymer PEDOT layer has been successfully coated on the surface of Li3V2(PO4)3 electrode through a facile chemical polymerization method. The structure and morphology of the as-synthesized core-shell Li3V2(PO4)3@PEDOT composite are investigated by the techniques ofXRD, SEM, TEM and EDS. It is found that the thickness of the polymerized PEDOT layer covering on the Li3V2(PO4)3 nanoparticles is about 3–10 nm. The electrochemical measurements demonstrate that the reversible capacity, rate capability and cycling performance of Li3V2(PO4)3 cathodehave beengreatly improvedby PEDOT coating, whichcould maintain a reversible capacity of 108.9 mAh g−1 after 500 cycles at 3C. The superior performance is ascribed to an enhanced electronic conductivity of the electrode emerging from the conductive nature of PEDOT, and it also reveal that this core-shell structured Li3V2(PO4)3@PEDOT has a promising application as cathode material for high energy lithium-ion batteries.