共查询到13条相似文献，搜索用时 93 毫秒
1.
应用循环伏安和恒电流充放电等方法研究了橄榄石型LiFePO4正极材料在季铵盐离子液体电解液中的电化学嵌脱锂性质。研究表明:电极的扫描速率和工作温度均可影响LiFePO4正极材料的充放电容量和循环性能。 相似文献
2.
本文采用流变相法合成纳米尺寸锂离子电池正极材料LiFePO4/C,并用X射线衍射(XRD),扫描电镜(SEM),透射电镜(SEM),热分析(TG-DSC)以及恒流充放电测试等方法进行结构和电化学性能表征。结果表明此方法合成的LiFePO4/C复合材料的粒径为50nm,表层的碳膜厚度为1～2nm,具有较好的振实密度,在充放电循环过程中有稳定的充放电平台和较高的循环稳定性以及良好的高倍率性能。 相似文献
3.
在无水溶胶凝胶法基础上,以Fe3＋盐为铁源,添加聚乙二醇-400作为表面活性剂,制备了掺杂钴的LiFePO4/C正极材料（LiFe1-xCoxPO4/C,x=0,0.05,0.1）。并通过XRD、SEM、恒流充放电等方法研究了不同钴掺杂量对LiFePO4/C结构、形貌和电化学性能的影响。 相似文献
4.
在无水溶胶凝胶法基础上,以Fe3+盐为铁源,添加聚乙二醇-400作为表面活性剂,制备了掺杂钴的LiFePO4/C正极材料(LiFe1-xCoxPO4/C,x=0,0.05,0.1)。并通过XRD、SEM、恒流充放电等方法研究了不同钴掺杂量对LiFePO4/C结构、形貌和电化学性能的影响。 相似文献
5.
橄榄石型结构的LiFePO4是一种新的锂离子电池正极材料。从提高材料的稳定性及降低锂离子电池的生产成本两方面出发,研究了用高温固相法合成橄榄石LiFePO4时,温度对其结构及电化学性能的影响。在氮气保护下,采用高温固相反应法在350oC预分解5h,650℃焙烧24h制备的LiFePO4具有较好的晶形、放电容量和循环性能,其首次放电容量达到92mAh／g,40次循环后放电容量达到77mAh／g,容量衰减16％。 相似文献
6.
与LiFePO4相比,单斜结构的磷酸钒锂（Li3V2(PO4)3）具有更高的Li+扩散系数和更高的放电电压、能量密度和高的比容量,已成为锂离子电池正极材料的研究热点之一,且被认为是新一代的高容量产业化电池材料。综述了近年来Li3V2(PO4)3的主要合成方法、充放电机理及其改性的研究现状,并且对Li3V2(PO4)3的发展趋势进行了展望。采用球磨辅助碳热还原法制备锂离子正极材料Li3V2(PO4)3,并通过金属离子掺杂技术对Li3V2(PO4)3进行改性。实验结果表明：掺杂少量的Fe后,材料放电容量增大且循环性能更好。 相似文献
7.
采用固相法和溶胶凝胶法（sol-gel）成功地制备出了LiFePO4．并利用X射线衍射、扫描电镜以及电化学测试等手段，系统地研究了合成条件和方法对材料的结构和电化学性能的影响．研究表明，使用sol—gel方法和固相法，制备出单一相的LiFePO4，其比容量分别为130mAh／g和80mAh／g．采用sol—gel方法制备的LiFePO4作为电池正极材料具有高的比容量和优良的电化学性能． 相似文献
8.
以LiMn1.5Ni0.5O4为锂离子电池备选的正极活性物质,通过充放电试验、X射线衍射试验、循环伏安试验等,研究其作为正极材料的电化学性能。 相似文献
9.
徐世林 《商丘职业技术学院学报》2008,7(2):100-102
LiFePO4是一种用于锂离子二次电池的潜在正极材料．LiFePO4微粒通过简单的共沉淀方法合成,为了增加其电子导电率,在水中用硝酸银溶液对LiFePO4进行包覆．粒子表面高分散的银提高了电子导电率和容量．不同电流密度下银包覆LiFePO4的电化学性能和其他高导电率的LiFePO4是相似的．银包覆是一种保持容量的有效方法,甚至在高的电流密度下也是如此． 相似文献
10.
采用液相沉淀法制备高密度的LiFePO4PC 正极材料, 利用扫描电镜(SEM) 、X 射线衍射(XRD) 、傅立叶红外光谱(FTIR) 、元素分析等对样品的表观形貌、晶体结构、谱学性质等进行了测试分析。结果表明,样品具有单一的橄榄石结构和314 V 左右的放电平台, 掺碳的LiFePO4 具有更优良的性能, 振实密度达1146 gPcm3 , 011 C 首次放电比容量为14416 mAhPg , 循环20 次后容量保持率为9312 %. 相似文献
11.
Lithium-ion batteries(LIBs) have been developed for over 30 years; however, existing electrode materials cannot satisfy the increasing requirements of high-energy density, stable cycling, and low cost. Here, we present a perovskite-type LaNiO_3 oxide(LNO) as a new negative electrode material. LNO was successfully synthesized by a sol–gel method. The microstructure and electrochemical performance of LNO calcined at various temperatures have been systematically investigated. The LNO electrode shows a high rate capability and long cycling stability. In a C-rate test, a specific capacity of 77 mAh/g was exhibited at 6 C. LNO can also deliver a specific capacity of 92 mAh/g after 200 cycles at 1 C. This paper presents a type of binary metal oxide as a new anode material for high-performance LIBs. 相似文献
12.
In this study, a bulk composite material symbolized as NiCo LDH-rGO/Ni F was developed by a solvothermal process for the first time. This material was fabricated through simultaneous growth of nickel-cobalt layered double hydroxide(NiCo LDH) and reduced graphene oxide(rGO) on nickel foam. This bulk composite can be used directly as a binder-free electrode for supercapacitors(SCs). The physicochemical properties of this composite were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The electrochemical properties of the composite were measured by the cyclic voltammetry and galvanostatic charge-discharge. The results show that this composite had a hierarchical structure and exhibited a significantly enhanced specific capacitance of up to 3383 F/g at 1 A/g. The asymmetric SC using this composite as a positive electrode had a high energy density of 40.54 Wh/kg at the power density of 206.5 W/kg and good cycling stability. Owing to the synergies between the metal oxides and the rGO, the preparation method of in situ growth and its hierarchical structure, this bulk composite displayed excellent electrochemical performance and had a promising application as an efficient electrode for high-performance SCs. 相似文献
13.
两相Mg-Ni合金的电化学吸放氢行为 总被引：1，自引：0，他引：1
刘卫红 《上海大学学报(英文版)》2002,6(4):349-352
The electrochemical performance of double phase Mg-Ni alloy was characterized at 25℃ and 70℃，in order to evaluate briefly its utility as negative electrode materials in nickel-metal hydride batteries.The results show that the electrochemical capacity of double phase Mg-Ni alloy is rarely low at 25℃,but increased rapidly when the temperature is enhanced,and the double phase Mg-Ni alloy has its maximum capacity at the first discharge cycle,but the capacity degrades rapidly with cycling number. 相似文献