物理化学学报 >> 2013, Vol. 29 >> Issue (05): 966-972.doi: 10.3866/PKU.WHXB201302281

电化学和新能源 上一篇    下一篇

碳气凝胶活化对于电极嵌锂性能的影响

刘念平, 沈军, 关大勇, 刘冬, 周小卫, 李亚捷   

  1. 上海市特殊人工微结构材料与技术重点实验室, 同济大学物理科学与工程学院, 上海200092
  • 收稿日期:2012-11-12 修回日期:2013-02-27 发布日期:2013-04-24
  • 通讯作者: 沈军 E-mail:shenjun67@tongji.edu.cn
  • 基金资助:

    国家自然科学基金(51072137, 50802064, 11074189); 国家科技支撑计划重点项目(2009BAC62B02)及上海科学技术委员会项目(11nm0501600)资助

Effect of Carbon Aerogel Activation on Electrode Lithium Insertion Performance

LIU Nian-Ping, SHEN Jun, GUAN Da-Yong, LIU Dong, ZHOU Xiao-Wei, LI Ya-Jie   

  1. Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, Institute of Physical Science and Engineering of Tongji University, Shanghai 200092, P. R. China
  • Received:2012-11-12 Revised:2013-02-27 Published:2013-04-24
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51072137, 50802064, 11074189), Key Projects in the National Science & Technology Pillar Program, China (2009BAC62B02), and Shanghai Committee of Science and Technology, China (11nm0501600).

摘要:

碳气凝胶由于其对于可充电锂离子电池的高能嵌锂特性, 近年来受关注程度逐渐增加. 碳气凝胶以间苯二酚-甲醛在碳酸钠催化下, 通过溶胶-凝胶工艺、常压干燥技术、碳化、活化后制得. 经CO2气体活化后的碳气凝胶结合了无定型和纳米多孔结构的优点, 在材料原有基础上丰富了多孔结构, 增加了嵌锂点位. 其中, 微孔提供了高比表面积和孔体积以容纳锂及其化合物; 介孔则提供了锂离子大量传输的通道, 从而使得电极具有更高的离子电导率. 这些微结构的优化使材料获得了更高的嵌锂比容量. 此外, 活化碳气凝胶显示了2032 m2·g-1的比表面积. X射线衍射(XRD)和扫描电子显微镜(SEM)的测试结果分别表明了其无定型特质以及纳米颗粒的网络状骨架. 该材料在首次和第50次恒流充放电(50 mA·g-1)循环的嵌锂容量分别为3870和352 mAh·g-1, 对应的可逆容量分别为658 和333 mAh·g-1. 表明了CO2活化对于改善碳气凝胶嵌锂性能的可行性, 且对于其它多孔电极材料的制备及特性优化提供了一种途径.

关键词: 碳气凝胶, 溶胶-凝胶, 气体活化, 无定型碳, 锂离子电池

Abstract:

Carbon aerogels have received much recent attention as high-capacity insertion anodes for rechargeable lithium ion batteries. Carbon aerogels were synthesized from resorcinol-formaldehyde with a sodium carbonate catalyst via a sol-gel process, ambient drying, carbonization, and activation. Gaseous CO2-activated carbon aerogels combined the advantages of amorphous and nanoporous structures, with richer porous structures and more lithium insertion points than conventional carbon aerogels. Microporosity analysis indicated a high surface area, and the pore volume effectively retained lithium and its compounds. The mesoporosity allowed the mass transport of Li+ and conferred high ionic conductivity to the electrode. These improvements led to a higher lithium insertion capacity, and the activated carbon aerogel exhibited a specific surface area of 2032 m2·g-1. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed an amorphous structure and nanoparticle network skeleton, respectively. Lithium insertion capacities of 3870 and 352 mAh·g-1 were exhibited in the 1st and 50th galvanostatic discharge-charge (50 mA·g-1) cycles, respectively. This corresponded to irreversible capacities of 658 and 333 mAh·g-1, respectively. This work demonstrates the feasibility of CO2 activation for improving lithium insertion performance in carbon aerogels, and provides preparation and optimization procedures for other porous electrode materials.

Key words: Carbon aerogel, Sol-gel, Gas activation, Amorphous carbon, Lithium ion battery

MSC2000: 

  • O646