李昌明
,
黄启明
,
张仁元
,
李伟善
,
赵灵智
,
胡社军
金属学报
用电沉积方法直接在铜集流体上分别制备出锂离子电池负极材料锡薄膜电极和锡颗粒电极。用X射线衍射、扫描电镜、循环伏安及充放电实验研究比较了二电极的性能。结果表明，在氟硼酸盐溶液中使用以醛类为主的复合添加剂，在静止条件下制得锡薄膜电极，搅拌条件下制得锡颗粒电极；锡薄膜电极比锡颗粒电极具有较优的初始嵌锂容量和循环稳定性：薄膜电极首次放电比容量达到了787mAh/g，40次循环时放电比容量仍保持630 mAh/g；而颗粒状电极首次放电比容量只有576 mAh/g，至20次循环时，放电比容量降到了150mAh/g。
关键词:
电沉积
,
Tin
,
Lithium ion battery
,
Anode materials
Xianhua HOU
金属学报(英文版)
Nano-level Sn-Ni alloy thin-film electrode materials prepared by magnetic sputtering technology are characterized with X-ray diffraction (XRD), atom force microscopy (AFM) and scanning electron microscopy (SEM). The charge/discharge and cyclic voltammograms (CV) of the films electrodes are tested by the battery testing system of high precision. The results indicate that the materials prepared by direct current (DC) and radio frequency (RF) methods differ greatly in their performance. Ni3Sn2 alloy phase constitutes the main components prepared by DC method, the particles on the surface are tiny and show steady cycling performance, the deficiency is that they have low initial efficiency and small discharge capacity of 72 % and 108 mA.h/g, respectively. Contrary to the former, Ni3Sn4 alloy phase constitutes the main components prepared by RF method, the particles on the surface appear comparatively larger, their discharge capacity did not decline in the first 15 times, keeping above 500 mA·h/g, but began to decline after 15 times.
关键词:
Lithium ion battery
,
Sn-Ni 合金
,
电化学性能 lithium ion battery
,
Sn-Ni alloy
,
electrochemical property
Halil Sahan
材料科学技术（英文）
Spinel LiMn2O4 was synthesized by glycine-nitrate method and coated with CaCO3 in order to enhance the electrochemical performance at room temperature (25°C) and 55°C. The uncoated and CaCO3-coated LiMn2O4 materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical tests. XRD and SEM results indicated that CaCO3 particles encapsulated the surface of the LiMn2O4 without causing any structural change. The charge-discharge tests showed that the specific discharge capacity fade of pristine electrode at 25 and 55°C were 25.5% and 52%, respectively. However, surface modified cathode shows 7.4% and 29.5% loss compared to initial specific discharge capacity at 70th cycle for 25 and 55°C, respectively. The improvement of electrochemical performance is attributed to suppression of Mn2+ dissolution into electrolyte via CaCO3 layer.
关键词:
LiMn2O4
Halil Sahan
材料科学技术（英文）
Spinel LiMn2O4 was synthesized by glycine-nitrate method and coated with CaCO3 in order to enhance the electrochemical performance at room temperature (25°C) and 55°C. The uncoated and CaCO3-coated LiMn2O4 materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical tests. XRD and SEM results indicated that CaCO3 particles encapsulated the surface of the LiMn2O4 without causing any structural change. The charge-discharge tests showed that the specific discharge capacity fade of pristine electrode at 25 and 55°C were 25.5% and 52%, respectively. However, surface modified cathode shows 7.4% and 29.5% loss compared to initial specific discharge capacity at 70th cycle for 25 and 55°C, respectively. The improvement of electrochemical performance is attributed to suppression of Mn2+ dissolution into electrolyte via CaCO3 layer.
关键词:
LiMn2O4
钟盛文
,
胡经纬
,
吴子平
,
梅文捷
新型炭材料
采用超轻的碳纳米管(Carbon nanotubes, CNTs)宏观膜替代传统的金属铝集流体,替换后的锂离子电池以 LiCoO2为活性物质,在1 C 条件下电池首次放电比容量为132.8 mAh·g-1,500次循环后容量保持率高于80%；当正极材料层面密度为16 mg·cm-2时,LiCoO2-CNT 电极的能量密度比 LiCoO2-Al 电极提高25%；同时,CNTs 膜作为正极集流体的电池自放电率低于1.5%。该 CNTs 膜经电流刺激后仍保持较高的石墨化程度,相比金属集流体,其表面束状的多孔结构可有效保证正极材料层和集流体间的紧密接触。该膜有望替代传统铝箔成为新一代锂离子电池用集流体。
关键词:
碳纳米管
,
锂离子电池
,
集流体
,
能量密度
刘鸿鹏
,
乔文明
,
詹亮
,
凌立成
新型炭材料
doi:10.1016/S1872-5805(08)60042-6
采用催化化学气相沉积法在微米硅颗粒表面原位生长纳米炭纤维得到纳米炭纤维/硅复合材料.利用SEM,TEM和XRD表征了复合材料的表面形态和微观结构,并考察了其作为锂离子电池负极材料的循环性能.电化学测试表明:与纳米纤维/硅机械混合物相比,原位生长纳米炭纤维/硅复合材料具有更高的可逆容量(1042mAh/g)和更好的循环稳定性.根据SEM和交流阻抗分析结果,分析了纳米炭纤维/硅复合材料在充放电过程中的结构演变机制,其优异的电化学性能主要来源于原位生长纳米炭纤维与硅颗粒之间良好的接触性能.
关键词:
锂离子电池
,
负极材料
,
纳米炭纤维
,
硅
