High performance Li3V2(PO4)3/C composite cathode material for lithium ion batteries studied in pilot scale test

Abstract

Li3V2(PO4)3/C composite cathode material was synthesized via carbothermal reduction process in a pilot scale production test using battery grade raw materials with the aim of studying the feasibility for their practical applications. XRD, FT-IR, XPS, CV, EIS and battery charge-discharge tests were used to characterize the as-prepared material. The XRD and FT-IR data suggested that the as-prepared Li 3V2(PO4)3/C material exhibits an orderly monoclinic structure based on the connectivity of PO4 tetrahedra and VO6 octahedra. Half cell tests indicated that an excellent high-rate cyclic performance was achieved on the Li3V 2(PO4)3/C cathodes in the voltage range of 3.0-4.3 V, retaining a capacity of 95% (96 mAh/g) after 100 cycles at 20C discharge rate. The low-temperature performance of the cathode was further evaluated, showing 0.5C discharge capacity of 122 and 119 mAh/g at -25 and -40 °C, respectively. The discharge capacity of graphite//Li3V 2(PO4)3 batteries with a designed battery capacity of 14 Ah is as high as 109 mAh/g with a capacity retention of 92% after 224 cycles at 2C discharge rates. The promising high-rate and low-temperature performance observed in this work suggests that Li3V 2(PO4)3/C is a very strong candidate to be a cathode in a next-generation Li-ion battery for electric vehicle applications. © 2010 Elsevier Ltd All rights reserved.