Li3V2(PO4)3/Cu composite cathode material was prepared via sol-gel method by adding of 1.8 wt% Cu powder into the precursor solution. The structural and physical properties, as well as the electrochemical performance of the material were compared with those of Cu-free Li3V2(PO4)3. X-ray diffraction showed that Cu did not enter the crystal structure of Li3V2(PO4)3. The Li3V2(PO4)3/Cu composite material had a higher electronic conductivity comparing with that of Cu-free Li3V2(PO4)3. Electrochemical impedance spectroscopy showed that the adding of Cu decreased the charge transfer resistance of the electrode. In addition, the lithium diffusion coefficient was prominently enhanced from 1.3×10-9 to 2.8×10-8cm2 s-1. Based on the these advantages, the Li3V2(PO4)3/Cu composite material exhibitedmuch better cycling performance than the Cu-free Li3V2(PO4)3.

The valence state and magnetic properties of hole-doped LiCuVO4 are investigated. By analyzing the Cu 2p core-level photoemission spectra, the holes are suggested to be introduced into Cu2þ site in the formation of Cu3þ ion. The calculation of effective moment also confirms the presence of nonmagnetic Cu3þ ion which should be responsible for the decrease of high-temperature susceptibility after hole doping. At low temperature, the antiferromagnetic transition at 26K and 2.3K disappears due to the enhancement of Curie term. Magnetic hysteresis at 2 K shows that there exists a small ferromagnetic moment of 0.15 emu/g in Li0.9CuVO4.

Layered LiNi0.4Mn0.4Co0.2O2 has been synthesized by citrate precursor method. Its magnetic properties are investigated by dc magnetization. The high-temperature susceptibility curve follows the Curie-Weiss law with Curie and Weiss constant 1.435(2) emu K/mol Oe and -112(4) K, respectively, larger than those values reported in previous researches, which possibly results from the difference in the synthesis process and sintered temperature. Our dc susceptibility differs from that of the homogeneous spin glass in that below Tirr field cooled (FC) curve continues to rise, while the FC curve is almost flat for homogeneous spin glass. Together with the de Almeida-Thouless line analysis, cluster spin glass is suggested to be the ground state of LiNi0.4Mn0.4Co0.2O2. Frustration parameter |Ø| /Tf in this system is estimated to be about four, lower than the value that frustration effect is strong enough to give rise to spin glass state. This fact indicates that the cluster-spin-glass results from the short-range structure disorder rather than the geometrical frustration.

采用两步反应制备了新型锂离子电池正极材料Li0.86V0.8O2.该材料具有六方层状结构，空间群为R3m.研究了在水热条件下溶液的碱度对于钒酸锂盐形成的影响，在低碱度的条件下，前驱体V2O3和LiOH·H2O并未发生反应，只有在碱度达到215mol/L时，才能形成单相的Li0.86V0.8O2材料.X射线光电子能谱分析发现，V2p的结合能位于516.4和523.1eV，分别对应于四价钒离子的V2p3/2和V2p1/2，这说明在Li0.86V0.8O2中V离子主要价位为+4价.在电流密度为714mA/g的充放电中，Li0.86V0.8O2初始充电容量达到163mA·h/g，首次放电容量也能达到113mA·h/g，20次循环后放电容量仍然可以达到80mA·h/g，表现出较好的循环性能.

Li[Li0.23Co0.3Mn0.47]O2 cathode material was prepared by a sol-gel method. The material had a primary particle size of about 100 nm, covered by a 30 Å of Li2CO3 layer. The material showed promising electrochemical performance when cycled up to 3C rate. The electrochemical kinetics of the first charge was much slower than that of the second charge, due to the complex electrochemical process which involved not only Li+ diffusion but also release of oxygen. By taking account of this, the material was pre-charged very slowly (～C/50) in the first cycle. This led to excellent electrochemical performance in the following cycles. For instance, the 1C-rate capacity increased to 168 mAhg-1 after 50 cycles, comparing with the 145 mAhg-1 obtained without pre-charging.