Enhancing the high-rate performance of Li3V2(PO4)3/C for Li-ion batteries via a synergistic effect of dual carbon sources

The large-scale application of Li-ion batteries requires high-performance cathode materials. Herein, a high-activity Li 3 V 2 (PO 4 ) 3 /C composite cathode has been fabricated through a solid-state reaction employing dual carbon sources of poly(acrylic acid) and soluble starch. The effects of single carbon source and dual carbon sources on the physical and electrochemical properties of Li 3 V 2 (PO 4 ) 3 /C are analyzed. The porous structure induced by poly(acrylic acid) and highly conductive carbon resulted from soluble starch enable the composite to achieve large discharge capacities and stable cyclability at high C-rates. At 3.0–4.3 V and 10 C, a large discharge capacity of 121 mAh g −1 (nearly 91% of the theoretical capacity) can be obtained, along with high capacity retention of 88% over 1000 cycles. Furthermore, at 3.0–4.8 V, the composite also possesses larger high-rate capacities and better cyclability than other composites prepared using single carbon source. The dual carbon sources bring a synergistic effect to the enhancement of electrochemical performances of the Li 3 V 2 (PO 4 ) 3 /C composite.