Characteristics of Li 3V 2(PO 4) 3/C powders prepared by ultrasonic spray pyrolysis

Abstract

Li 3V 2(PO 4) 3 and Li 3V 2(PO 4) 3/C powders are prepared by ultrasonic spray pyrolysis from spray solutions with and without sucrose. The precursor powders have a spherical shape and the crystal structure of V 2O 3 irrespective of the concentration of sucrose in the spray solution. The powders post-treated at 700 °C have the pure crystal structure of the Li 3V 2(PO 4) 3 phase irrespective of the concentration of sucrose in the spray solution. The Li 3V 2(PO 4) 3 powders prepared from the spray solution without sucrose have a non-spherical shape and hard aggregation. However, the Li 3V 2(PO 4) 3/C powders prepared from the spray solution with sucrose have a spherical shape and non-aggregation characteristics. The Li 3V 2(PO 4) 3 powders prepared from the spray solution without sucrose have a low initial discharge capacity of 122 mAh g −1. However, the Li 3V 2(PO 4) 3/C powders prepared from the spray solutions with 0.1, 0.3, and 0.5 M sucrose have initial discharge capacities of 141, 130, and 138 mAh g −1, respectively. After 25 cycles, the discharge capacities of the powders formed from the spray solutions with and without 0.1 M sucrose are 70% and 71% of the initial discharge capacities, respectively.