复合氧化物Ca_(1-x)Pb_xMnO_(3-σ)的合成及其电化学性能研究

采用共沉淀法制得Ca_(1-x)Pb_xMnO_(3-σ)的XRD测试结果表明该样品具有钙 钛结构，利用X射线光电子能谱(XPS)对Ca_(0.9)Pb_(0.1)MnO_(3-σ)样品中各元素 的价态进行了鉴定，结果表明各元素分别以Ca~(2+)，Pb~(4+)，Mn~(4+)以及少量 的Mn~(3+)的形式存在。四探针电导率测试结果发现Ca_(0.9)Pb_(0.1)MnO_(3-σ) 的电导率比无取代CaMnO_(3-σ)样品的电导率提高了将近两个数量级。并且半导体 的类型发生了变化。在碱性溶液中Ca_(0.9)Pb_(0.1)MnO_(3-σ)表现出良好的电化 学性能，9 mol/L KOH电解质溶液中，50 mg样品采用2 mA放电至-0.8 V时放电容量 为384 mA·h/g左右。并利用循环伏安对其充放电机理进行了初步探讨。

Studies on the Synthesis of Ca1- xPbxMnO3-σ and Its Electrochemical Performance

A series samples of Ca_(1-x)Pb_xMnO_(3-σ) have been synthesized by co-deposition method. Their structures were analyzed and characterized by X-ray diffraction (XRD) and X-ray electron spectroscopy (XPS). The results show that these samples are perovskite-type structure with Ca~ (2+), Pb~(4+), and Mn~(4+) respectively and a minor amount of Mn~(3+). The conductivity value of Ca_(0.9)Pb_(0.1)MnO_(3-σ) is two orders of magnitude higher than that of CaMnO_(3-σ) and the semiconductivity- type changes from n-type for CaMnO_(3-σ) to p-type for Ca_(0.9)Pb_(0.1) MnO_(3-σ). The discharge capacity of Ca_(0.9)Pb_(0.1)MnO_(3-σ) in 9 mol/L KOH solution is about 380 mA·h/g at the discharge regime — 2 mA galvanostatic to cutoff voltage of -0.8 V(vs. Hg/HgO). Cyclic voltammetry and galvanostatic charge-discharge studies show Ca_(0.9) Pb_(0.1)MnO_(3-σ) has a better rechargeability than the International common Sample (I. C. No. 1) in alkaline solution. The mechanism is preliminarily discussed.