High-Performance Lithium-ion Supercapatteries Constructed Using Li3V2(PO4)3/C Mesoporous Nanosheets

Abstract

To construct “non-consumable electrolyte type” or “internal serial hybrid type” lithium-ion supercapatteries with both high power and energy densities, carbon-coated lithium vanadium phosphate composite (Li3V2(PO4)3/C) is utilized as the cathode. This cathode with a high specific area is synthesized by a hydrothermal method assisted by delayed sol-gel method and using the surfactant of myristyltrimethylammonium bromide as the carbon source. It is self-assembled and mesoporous. This cathode has a high specific surface area of 40.92 m2 g−1, a pore volume of 0.095 cm3 g−1, a considerably high initial discharge capacity of 166 mAh g−1 at 0.2 C-rate. Even at 20 C-rate, the high discharge capacity of 90 mAh g−1 is maintained. The lithium-ion supercapattery assembled using this cathode, the anode of activated carbon as exhibits a discharge time of as long as 1369.24 s, a maximum energy density of 53.22 Wh kg−1, and a maximum power density of 3.01 kW kg−1. Such lithium-ion supercapatteries thus overcome the disadvantages of rapid energy density attenuation under high power density of existed lithium-ion supercapatteries.