摘要
以酚醛树脂为碳源,通过高温热解法成功制备了硅碳复合材料(Si/C)。采用热重分析、X射线衍射和扫描电镜方法表征材料的组成、结构和形貌,采用恒流充放电测试、循环伏安法和交流阻抗谱探究了原料配比对硅碳复合材料电化学性能的影响。结果表明,纳米硅与酚醛树脂质量比为1∶1时,纳米硅表面被热解碳均匀包覆,有效提高了复合材料的电化学储能性能。这是因为碳包覆层有助于提高材料的导电率,并缓解硅在放电过程中的体积膨胀。测试发现材料在0.1C倍率下首次充放电比容量为1546 mAh/g;循环50次后可逆比容量为1443 mAh/g,容量保持率达93%;在1C倍率下仍具有1224 mAh/g的可逆比容量。
Silicon carbon(Si/C)composites were synthesized by a high-temperature pyrolysis methode using phenolic resin as carbon source.Thermogravimetric analysis,X-ray diffraction and scanning electron microscope techniques were applied to characterize the composition and morphology of the as-synthesized Si/C composites.Galvanostatic charge/discharge tests,cyclic voltammetry and electrochemical impedance spectroscopy measurements were employed to investigate the influence of the carbon content on the electrochemical performance of the as-synthesized Si/C electrodes.It is found that when the starting mass ratio of nano silicon to phenolic resin is 1∶1,nano silicon can be uniformly coated with pyrolysis carbon,which limits the volume expansion of silicon.This composite exhibits an initial discharge specific capacity of 1546 mAh/g at 0.1C.A reversible specific capacity of 1443 mAh/g is remained after 50 cycles discharging/charging test,along with a capacity retention of 93%.At the current rate of 1C,the specific capacity is still 1224 mAh/g.This work proposes a novel strategy for developing high-performance silicon/carbon composite as the cathode materials for lithium-ion batteries.
作者
周钰杰
彭雨佳
赵强
孙艳
闫康平
ZHOU Yujie;PENG Yujia;ZHAO Qiang;SUN Yan;YAN Kangping(School of Chemical Engineering,Sichuan University,Chengdu 610000,China;School of Mechanical Engineering,Chengdu University,Chengdu 610106,China)
出处
《电子元件与材料》
CAS
CSCD
北大核心
2020年第2期27-32,共6页
Electronic Components And Materials
基金
国家自然科学基金(51702027)
关键词
硅
酚醛树脂
碳
包覆
容量
循环性能
silicon
phenolic resin
carbon
coating
capacity
cycling capability