Influences of neodymium doping on magnetic and electrochemical properties of Li3V2(PO4)(3)/C synthesized via a sol-gel method

摘要

A series of neodymium doped Li3V2-xNd5(PO4)(3)/C cathode materials have been successfully synthesized by a citric acid assisted sal gel method. Nd doped samples (x < 0.10) have well developed monoclinic structure of Li3V2(PO(4))3 with enlarged unit cell volume. All samples present typical characteristics of paramagnetism in 4< T < 300 K, but the magnetic susceptibilities of Nd doped samples increase with Nd content (except for x = 0.15). Nd doped composites show better electrochemical property than that of the undoped one. Among them, the Li3V1.95Nd0.05(PO4)(3)/C displays the highest capacity and best cycle stability. The Li3V1.95Nd0.05(PO4)(3)/C presents the first discharge capacity of 129.2 mAh g(-1) at 1 degrees C rate in the voltage range of 3.0-4.3 V, 21.7% higher than that of Li3V2(PO4)(3)/C. And no capacity loss occurs after 100 cycles. The high structural stability, low charge-transfer resistance and rapid Li+ diffusion due to the presence of Nd3+ are mainly responsible for the superior electrochemical performance of Nd doped Li3V2(PO4)(3)/C cathode materials. (C) 2015 Elsevier B.V. All rights reserved.