锰基氧化物及硫化物的制备及其电化学性能研究

发布时间：2018-03-10 10:41

  本文选题：MnO@Ni　切入点：NiS_2-MnS　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：锰基氧化物及硫化物纳米材料因其组成和性质的多样性,在锂离子电池负极材料和超级电容器电极材料方面具有广泛的应用。本文先通过一步共沉淀法合成微米球形碳酸盐前躯体,再采用一步煅烧控制还原法和溶剂热法,分别制备了MnO@Ni微米球、NiS2-MnS多级结构,并研究了它们的电化学性能。主要研究内容如下:1、以乙酸镍和乙酸锰为原料,碳酸氢钠为沉淀剂,先通过共沉淀法合成镍锰碳酸盐前驱体,再采用煅烧控制还原法,制备了 MnO@Ni微米球。采用X-射线衍射(XRD)、扫描电镜(SEM)、射线光电子能谱(XPS)等测试手段对产物的物相、形貌结构进行了表征,研究了其作为锂离子电池负极材料的相关电化学性能。实验结果表明:在所制备的几组样品中,当Ni:Mn摩尔比为1:10时,所得产物具有最好的电化学性能。在0.1 C倍率下的放电容量为851.2 mAh g-1。在0.5 C倍率下经过200次循环后仍保持285.7 mAh g-1的放电比容量,其容量保持率为72%,具有优异的循环稳定性。2、以乙酸镍和乙酸锰为原料,碳酸氢钠为沉淀剂,通过共沉淀法合成镍锰碳酸盐前驱体,然后采用硫代乙酰胺在溶剂热条件下进行硫化,制备了 NiS2-MnS多级结构。对产物的物相、形貌结构进行了表征,并研究了其作为超级电容器电极材料的相关电化学性能。结果表明:当反应温度为150℃,反应时间为12 h时,得到硫化完全的产物,并具有较完整的球形结构。在1Ag-1电流密度下其比容量为630.8 Fg-1,具有优异的倍率性能,经过1000次循环后,比容量为205 Fg-1,容量保持率大约为70%,具有良好的倍率性能与循环稳定性。
[Abstract]:Manganese based oxides and sulphide nanomaterials due to their diversity in composition and properties, It has been widely used in cathode materials of lithium ion batteries and electrode materials of supercapacitors. In this paper, microsphere carbonate precursors were synthesized by one step coprecipitation method, and then one-step calcination-controlled reduction method and solvothermal method were used. The multistage structures of MnO@Ni microspheres NiS2-MnS were prepared and their electrochemical properties were studied. The main contents of the study were as follows: (1) Nickel acetate and manganese acetate were used as raw materials and sodium bicarbonate was used as precipitant to synthesize nickel-manganese carbonate precursor by co-precipitation method. The MnO@Ni microspheres were prepared by calcination-controlled reduction method. The phase and morphology of the products were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of the materials used as anode materials for lithium ion batteries were studied. The experimental results show that the Ni:Mn molar ratio is 1:10 in several groups of samples. The discharge capacity of the product is 851.2 mAh g -1 at 0. 1 C rate. The discharge capacity of 285.7 mAh g-1 is maintained at 0. 5 C rate after 200 cycles. Its capacity retention ratio is 72, and it has excellent cycling stability. Nickel manganese carbonate precursor was synthesized by co-precipitation method with nickel acetate and manganese acetate as raw materials and sodium bicarbonate as precipitant. The multistage structure of NiS2-MnS was prepared by sulfidation of thioacetamide under solvothermal conditions. The phase and morphology of the product were characterized. The electrochemical properties of the supercapacitor electrode material were studied. The results showed that when the reaction temperature was 150 鈩，

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