用于锂离子电池的多孔珊瑚状硅/碳复合负极材料的合成、表征及电化学性能

利用PVA碳源包覆、HF酸刻蚀和沥青二次包覆方法制备多孔珊瑚状硅/碳复合负极材料,得到沥青含量分别为30%、40%和50%（质量分数）的3种硅/碳复合材料样品。采用XRD和SEM分别对复合材料的组成和形貌进行表征,并采用电化学测试手段对其性能进行测试。结果表明,经二次沥青包覆后,复合材料的电化学性能得到明显提高。当二次包覆的沥青含量为40%时,在100 m A/g的电流密度下,该样品第二次充放电循环的放电容量达到773 m A·h/g,经60次循环后,放电容量仍然保持在669 m A·h/g,其容量损失率仅为0.23%/cycle。因此,调整二次包覆碳含量可明显改善复合材料的循环稳定性。...

Full description

Saved in:
Bibliographic Details
Published in中国有色金属学报：英文版 Vol. 25; no. 12; pp. 4046 - 4053
Main Author 唐芬玲 雷建飞 崔朝阳 欧阳剑 刘钢 赵灵智
Format Journal Article
LanguageEnglish
Published 2015
Subjects
二次包覆
珊瑚状结构
硅/碳复合材料
负极材料
锂离子电池
Online AccessGet full text

Cover

More Information
Summary:利用PVA碳源包覆、HF酸刻蚀和沥青二次包覆方法制备多孔珊瑚状硅/碳复合负极材料,得到沥青含量分别为30%、40%和50%（质量分数）的3种硅/碳复合材料样品。采用XRD和SEM分别对复合材料的组成和形貌进行表征,并采用电化学测试手段对其性能进行测试。结果表明,经二次沥青包覆后,复合材料的电化学性能得到明显提高。当二次包覆的沥青含量为40%时,在100 m A/g的电流密度下,该样品第二次充放电循环的放电容量达到773 m A·h/g,经60次循环后,放电容量仍然保持在669 m A·h/g,其容量损失率仅为0.23%/cycle。因此,调整二次包覆碳含量可明显改善复合材料的循环稳定性。
Bibliography:43-1239/TG
Si/C composite; secondary coating; coral structure; anode material; Li-ion battery
Fen-ling TANG,Jian-fei LEI,Zhao-yang CUI,Jian OUYANG,Gang LIU,Ling-zhi ZHAO （ 1. Key Laboratory of Nanophotonic Functional Materials and Devices of Guangdong Province, Institute of Opto-Elcctronic Materials and Technology, South China Normal University, Guangzhou 510631, China, 2. Guangdong Food and Drug Vocational-Technical School, Guangzhou 510663, China, 3. School of Physics and Engineering, Henan University of Science and Technology, Luoyang 471023, China, 4. Guangdong Engineering Technology Research Center of Low Carbon and Advanced Energy Materials, Guangzhou 510631, China）
A porous coral-structured Si/C composite as an anode material was fabricated by coating Si nanoparticles with a carbon layer from polyvinyl alcohol（PVA）, erosion of hydrofluoric（HF） acid, and secondary coating with pitch. Three samples with different pitch contents of 30%, 40% and 50% were synthesized. The composition and morphology of the composites were characterized by X-ray diffractometry（XRD） and scanning electron microscopy（SEM）, respectively, and the properties were tested by electrochemical measurements. The results indicated that the composites showed obviously enhanced electrochemical performance compared with that without secondary carbon coating. The second discharge capacity of the composite was 773 m A·h/g at a current density of 100 m A/g, and still retained 669 m A·h/g after 60 cycles with a small capacity fade of less than 0.23%/cycle, while the content of secondary carbon source of pitch was set at 40%. Therefore, the cycle stability of the composite could be excellently improved by regulating carbon content of secondary coating.
ISSN:1003-6326