分别以葡萄糖和乙炔黑为碳源,采用固相烧结法制备Sn-Co/C锂离子电池负极复合材料,探讨碳源种类对材料结构和电化学性能的影响规律。结果表明:摩尔比为1:1的Sn-Co合金由Co Sn相和微量Co Sn2相组成;在Sn-Co/C复合材料中,大部分葡萄糖热解...分别以葡萄糖和乙炔黑为碳源,采用固相烧结法制备Sn-Co/C锂离子电池负极复合材料,探讨碳源种类对材料结构和电化学性能的影响规律。结果表明:摩尔比为1:1的Sn-Co合金由Co Sn相和微量Co Sn2相组成;在Sn-Co/C复合材料中,大部分葡萄糖热解炭和乙炔黑存在于Sn-Co合金颗粒表面,少部分进入颗粒内部,会在一定程度上阻碍Sn-Co合金的相变反应,残留微量Co Sn2和Co3Sn2相,同时阻碍Sn-Co合金晶粒或颗粒的长大,起到细化晶粒或颗粒的作用。添加葡萄糖热解炭和乙炔黑有利于提高Sn-Co/C复合材料的电子导电和Li+扩散,从而提高其电化学活性;并且添加葡萄糖的Sn-Co/C复合材料电化学性能更好,在电流密度为0.05 m A/cm2条件下的首次可逆放电容量为325 m A·h/g,经过100次循环后的容量保持率达到70.8%,循环性能比Sn-Co合金的提高26.8%,显示出良好的结构稳定性。展开更多
以金属锡粉(Sn)、金属钴粉(Co)和乙炔黑为主要原料,综合利用固相烧结和高能球磨的方法制备出Sn-Co-C复合负极材料,采用XRD、SEM、EDS和恒电流充放电等技术对材料进行了表征和电性能测试.实验结果表明:高能球磨处理后,Sn-Co-C复合材料颗...以金属锡粉(Sn)、金属钴粉(Co)和乙炔黑为主要原料,综合利用固相烧结和高能球磨的方法制备出Sn-Co-C复合负极材料,采用XRD、SEM、EDS和恒电流充放电等技术对材料进行了表征和电性能测试.实验结果表明:高能球磨处理后,Sn-Co-C复合材料颗粒尺寸减小,首次放电容量显著提升,为476.8 m Ah/g;经过30次循环后可逆容量仍保持在394.4 m Ah/g.展开更多
Alloy anodes were studied for pursuing Sn-based microcomposite synthesis, assembly and performance for lithium ion batteries. The self-assembled Sn-Co-C composites with nano-scaled microstructures were prepared via so...Alloy anodes were studied for pursuing Sn-based microcomposite synthesis, assembly and performance for lithium ion batteries. The self-assembled Sn-Co-C composites with nano-scaled microstructures were prepared via solution method and carbothermal technology. The morphology and physical structure were investigated with scanning electron microscope (SEM) and X-ray diffraction (XRD). The as-prepared materials were assembled to half cell coin for the purpose of discussing the galvanostatic cycling, cyclic voltammetry and rate-capability performance. Results reveal that nanoscaled CoSn 2 alloys covered with Sn and C layer by layer are wrapped by cross-linked porous carbon network to form spherical microstructure. This distinguishing feature of Sn-Co-C composites provides a possible solution to the problems of Sn particle aggregation and poor electron transport, and has strong effect on improving electrochemical performance.展开更多
文摘分别以葡萄糖和乙炔黑为碳源,采用固相烧结法制备Sn-Co/C锂离子电池负极复合材料,探讨碳源种类对材料结构和电化学性能的影响规律。结果表明:摩尔比为1:1的Sn-Co合金由Co Sn相和微量Co Sn2相组成;在Sn-Co/C复合材料中,大部分葡萄糖热解炭和乙炔黑存在于Sn-Co合金颗粒表面,少部分进入颗粒内部,会在一定程度上阻碍Sn-Co合金的相变反应,残留微量Co Sn2和Co3Sn2相,同时阻碍Sn-Co合金晶粒或颗粒的长大,起到细化晶粒或颗粒的作用。添加葡萄糖热解炭和乙炔黑有利于提高Sn-Co/C复合材料的电子导电和Li+扩散,从而提高其电化学活性;并且添加葡萄糖的Sn-Co/C复合材料电化学性能更好,在电流密度为0.05 m A/cm2条件下的首次可逆放电容量为325 m A·h/g,经过100次循环后的容量保持率达到70.8%,循环性能比Sn-Co合金的提高26.8%,显示出良好的结构稳定性。
文摘以金属锡粉(Sn)、金属钴粉(Co)和乙炔黑为主要原料,综合利用固相烧结和高能球磨的方法制备出Sn-Co-C复合负极材料,采用XRD、SEM、EDS和恒电流充放电等技术对材料进行了表征和电性能测试.实验结果表明:高能球磨处理后,Sn-Co-C复合材料颗粒尺寸减小,首次放电容量显著提升,为476.8 m Ah/g;经过30次循环后可逆容量仍保持在394.4 m Ah/g.
基金Projects(51074185, 51274240) supported by the National Natural Science Foundation of ChinaProject supported by the Fundamental Research Funds for the Central Universities
文摘Alloy anodes were studied for pursuing Sn-based microcomposite synthesis, assembly and performance for lithium ion batteries. The self-assembled Sn-Co-C composites with nano-scaled microstructures were prepared via solution method and carbothermal technology. The morphology and physical structure were investigated with scanning electron microscope (SEM) and X-ray diffraction (XRD). The as-prepared materials were assembled to half cell coin for the purpose of discussing the galvanostatic cycling, cyclic voltammetry and rate-capability performance. Results reveal that nanoscaled CoSn 2 alloys covered with Sn and C layer by layer are wrapped by cross-linked porous carbon network to form spherical microstructure. This distinguishing feature of Sn-Co-C composites provides a possible solution to the problems of Sn particle aggregation and poor electron transport, and has strong effect on improving electrochemical performance.
