【作者】 钟婧；

【导师】 涂江平；

【作者基本信息】 浙江大学 ， 材料科学与工程， 2011， 硕士

【摘要】 随着锂离子电池的广泛应用，锂离子电池负极材料成为了研究的热点。NiO由于其高比容量、无毒、价廉、原料丰富等优点倍受关注,是非常有前景的锂离子电池负极材料。本文主要研究内容是探索制备高容量NiO的方法及改善NiO电极的循环性能。采用电化学沉积法以镍铵络合物为电解液制备了表面形貌分别为颗粒状、棒状及片状多孔的NiO薄膜。其形貌与电沉积的电流密度大小有关,随着沉积电流密度的减小,薄膜的表面积增加,薄膜的循环稳定性提高。0.1 mA cm-2电流密度下电沉积的片状多孔薄膜循环50次后的容量保持率为49.5%,高于1 mAcm-2电流密度下电沉积的颗粒状薄膜的23.1%。采用化学浴沉积法以尿素为原料制备了泡沫镍负载NiO球状多孔膜。多孔结构提高了电极的电化学性能。进一步通过电沉积法在NiO膜表面镀镍,制备了球状多孔NiO/Ni复合薄膜。与Ni复合不仅提高了膜的导电性,还能有效维持NiO的球状多孔结构。镀镍后的NiO/Ni膜循环性能明显提高,在2 C倍率下循环50次后的可逆容量为506 mAh g-1,容量保持率为90.4%。采用氨水挥法诱导法制备了泡沫镍负载“三明治”形貌NiO薄膜,并基于扫描电镜和透射电镜观察探索了其形成过程及原理。它的特殊“三明治”层状结构使它具有良好的导电性和结构稳定性,该薄膜在2 C倍率下循环50次后的可逆容量为400 mAh g-1,容量保持率为78%。采用静电纺丝法制备了NiO及NiO/Ag复合纳米线,该纳米线由NiO和Ag的纳米颗粒组成。采用沉淀—水热法制备了NiO和NiO/CNT复合纳米材料,其中NiO为纳米片状结构,连接在纳米碳管上。这些纳米复合材料不仅具有高的比表面积,而且通过与高导电性材料的复合,可提高其导电性能,是具有应用潜力的锂离子电池电极材料。更多还原

【Abstract】 Along with the broad applications of lithium ion batteries, anode materials for lithium ion battery are researched abundantly. NiO has been paid much attention due to its attractive advantages such as high theoretic capacity, nontoxicity and low material cost. The main content of the present research is to explore new synthesis methods and improve the cycling performance of NiO as an anode material for lithium ion batteries.NiO films with different morphologies were prepared by electrodeposition, including dence film, nanorod-like film and net-like porous film. The morphology is determined by the current density. With the decrease of the current density, the specific surface area as well as the cycling performance of the film increase. The specific capacity of the porous film deposited at 0.1 mA cm-2 retains 49.5% of that in the 2nd cycle, higher than that of the dence film deposited at 1 mA cm-2 (23.1%).Nickel foam-supported porous NiO/Ni films were prepared by chemical bath deposition and electrodeposition. The Ni plating can enhance the conductivity and the stability of the structure. This porous NiO/Ni film exhibits excellent cycling performance, its reversible capacity sustains 506 mAh g-1 after 50 cycles at 2 C, which retains 90.4% of that in the 2nd cycle.Sandwich-like Ni(OH)2 and NiO films are synthesized by a simple ammonia-evaporation method on nickel foam. A plausible formation mechanism is proposed based on the observations of scanning electron microscopy and transmission electron microscopy. The reversible capacity of the sandwich-like NiO film sustains 400 mAh g-1 after 50 cycles at 2 C, which retains 78% of that in the 2nd cycle. The high rate capability and reversibility of this NiO film can be attributed to its unique sandwich-like architecture.NiO and NiO/Ag hybrid nanofibers were prepared by electrospinning. The nanofibers are composited by little NiO and Ag nanoparticles. NiO and NiO/CNT were prepared by deposition-hydrothermal method, in which the NiO nanoplates attachs to the CNT. These nanocomposites not only have high surface area, but also have enhanced conductivity. They are promising electrode material for Li ion battery.更多还原