磁控溅射制备的铜钒氧化物薄膜及其电化学性能

Structure and Electrochemical Performance of Copper Doped Vanadium Oxide Thin Films Deposited by RF Magnetron Sputtering

采用射频磁控溅射技术在硅基底上分别制备了无掺杂和掺杂Cu的氧化钒薄膜.X射线衍射(XRD)分析和扫描电子显微镜(SEM)观察表明,无掺杂的薄膜为多晶V2O5,掺杂Cu的薄膜为非晶态.X射线光电子能谱(XPS)分析结果表明,掺杂Cu的薄膜为铜钒氧化物膜,其中Cu离子表现为+2价,V离子为+4与+5价的混合价态.随着Cu掺杂量的增大,+4价V的含量增加.电化学测试结果表明,V2O5薄膜在掺杂Cu以后其放电容量有显著的提高,其中Cu2.1VO4.4薄膜在100次循环后容量还保持为83.4μA.h.cm-2.μm-1,表现出较高的放电容量和较好的循环性能.

V2O5 was used as cathode material for all solid state thin film lithium-ion batteries, so as to improve electrochemical properties of V2O5 thin film material. In this paper, copper doped and undoped vanadium oxide films were deposited on silicon substrates by RF magnetron sputtering. The films were characterized by XRD, SEM and XPS. The results show that undoped thin films are polycrystalline-V2O2 and copper doped thin films are amorphous copper-vanadium oxide. The Cu ions are at ＋ 2 oxidation state, while the V ions are mixed with ＋ 4 and ＋ 5 oxidation state. With increasing the concentration of doped Cu, the ratio of V^4＋/V^5＋ increases. The electrochemical tests show that doping copper contribute to increase the capacity of V2O2 films. The film with a composition of Cu2.1VO4.4 indicate highest capacity among all samples and is observed better cycleability, which is 83.4 μA · h · cm^-2 · μm^-1 up to 100 cycles.