Enhanced rate performance of Li3V2(PO4)3/C cathode by an improved rheological phase assisted microwave method

Rheological phase assisted microwave heating, for the first time, was utilized to prepare Li3V2(PO4)3/C composite by combining both advantages of rheological phase method and microwave irradiation. Benefiting from merits of both synthesis routes, the composite possesses an ultrahigh specific capacity of 101.8 mA h g−1 at 50 C rate and does not show any significant decay after long cycling life. [Display omitted] •Rheological phase assisted microwave can utilize both advantages of two methods.•Polyethylene glycol was used as both rheological medium and carbon precursor.•101.8 mA h g−1 of specific capacity was obtained at 50 C rates. In this study, high-rate Li3V2(PO4)3/C composite is successfully synthesized via an improved rheological phase assisted microwave method using polyethylene glycol as both rheological medium and carbon precursor. The relatively uniform Li3V2(PO4)3 particles are encapsulated in amorphous carbon architecture to form core-shell structure, providing effective electron and ion transport. When used as a cathode material in lithium ion battery, the Li3V2(PO4)3/C composite displays a maximum discharge capacity of 101.8 mA h g−1 at 50 C charge/discharge rate and still possesses 98.3% of capacity retention after 100 cycles, demonstrating superior rate capability and excellent cycling stability when compared with bare Li3V2(PO4)3. The observed electrochemical performance could be attributed to uniform coated-carbon pyrolysis from polyethylene glycol rheological phase precursor and small Li3V2(PO4)3 pristine particles synthesized by the fast microwave heating route.