Study on Carbon-coating Li_3V_2(PO_4)_3 Cathode Materials Prepared with Different Carbon Sources

摘要

Lithium-ion battery cathode materials, Li_3V_2(PO_4)_3/C, were prepared via rheological phase method. Li_2CO_3, NH_4H_2PO_4, V_2O_5 were employed as raw materials, and citric acid or polyethylene glycol (PEG) was used as the chelating agent (carbon source). The structure, morphology characters and the electrochemical performances of the samples were tested. The results show that modification by carbon-coating is favorable for the growth of particles. The primary particle size obviously decreases with PEG added, while the agglomeration of primary particles could be inhibited using the citric acid as carbon source, which makes particle size more uniform. Moreover, the electrochemical test results show that both the two kinds of carbon sources can effectively improve the specific capacity and the cycling performance compared with the uncoated sample.