V_2O_5复合薄膜材料的电子结构研究

STUDY ON ELECTRONIC STRUCTURE OF V_2O_5 COMPOSITE FILMS

采用自洽场离散变分Xα 方法对纯V2 O5及V2 O5复合薄膜不同状态的O1s及V2p轨道电子结合能和键强度等进行了研究 .结果表明 ,V2 O5结构中存在 4种状态的氧和 3种状态的钒 ,聚合物 (PEO)或聚合物 (PEO)—Li+ 嵌入V2 O5结构主要存在于层间的位置 ,与双键氧产生弱的键合作用 ,导致双键氧与五价钒的含量降低 ,三键氧与三价、四价钒的含量增加 ;纯V2 O5层间嵌入的Li+ 与周围氧的共价键与静电力都非常明显 ,V2 O5层间引入PEO后再嵌入Li+ ,Li+ 与周围氧的共价键与静电力都变的非常微弱 ,说明PEO嵌入V2 O5层间使Li+ 具有很好的注入

The binding energies and bond strengths of O 1 s and V 2 p orbits in V 2O 5 and V 2O 5 composite film were investigated by selfconsult charge_discrete variation-X α(SCC-DV-X α) method. The results show that there are four kinds of oxygen and three kinds of vanadium in the microstructure of V 2O 5. Weak bonds were generated between poly(ethylene_oxide) PEO or PEO-Li + intercalated into the layers of V 2O 5 microstructure and double_bond oxygen, leading to a decrease of double_bond oxygen and V 5+ as well as an increase of triple_bond oxygen, V 3+ and V 4+ . It was found that there were strong covalent bonds and ionic bonds between Li + ions, which were intercalated into the layers of V 2O 5 microstructure, and oxygen around them. With the intercalation of Li + ions into the layers of V 2O 5-PEO, covalent bond and ionic bond between the intercalated Li + ions and oxygen around them became faint. Correspondingly, excellent reversibility of intercalation/deintercalation of Li + ions was attained due to the intercalation of PEO into the la_ yers of V 2O 5 microstructure.