化工学报 ›› 2016, Vol. 67 ›› Issue (11): 4779-4786.DOI: 10.11949/j.issn.0438-1157.20160651

• 表面与界面工程 • 上一篇    下一篇

利用表面改性制备磷酸锰锂/石墨烯锂离子电池复合材料

赵兵, 王志轩, 陈卢, 杨雅晴, 陈芳, 高阳, 蒋永   

  1. 上海大学环境与化学工程学院, 上海 200444
  • 收稿日期:2016-05-11 修回日期:2016-07-21 出版日期:2016-11-05 发布日期:2016-11-05
  • 通讯作者: 蒋永,jiangyong@shu.edu.cn
  • 基金资助:

    国家自然科学基金项目(21501119, 11575105);上海市科委技术标准项目(15DZ0501402)。

LiMnPO4/graphene nanocomposites with high electrochemical performancefor lithium-ion batteries

ZHAO Bing, WANG Zhixuan, CHEN Lu, YANG Yaqing, CHEN Fang, GAO Yang, JIANG Yong   

  1. Institute of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
  • Received:2016-05-11 Revised:2016-07-21 Online:2016-11-05 Published:2016-11-05
  • Supported by:

    supported by the National Natural Science Foundation of China (21501119, 11575105) and the Science and Technology Committee of Shanghai (15DZ0501402).

摘要:

3-氨丙基三甲氧硅烷(APS)改性的磷酸锰锂纳米片与氧化石墨烯通过静电自组装,经喷雾干燥和高温煅烧,得到磷酸锰锂/石墨烯复合材料。APS修饰后的磷酸锰锂带正电荷,并可通过红外光谱中3-氨丙基和Si-O-C官能团的存在证明磷酸锰锂成功被APS修饰,使得其与带负电荷的氧化石墨烯自组装形成磷酸锰锂/石墨烯复合材料。测试结果表明约25 nm的磷酸锰锂纳米颗粒均匀负载在石墨烯表面,石墨烯片层充当导电网络,提高了材料的电子电导率和锂离子扩散速率,缓解了LiMnPO4在充放电过程中的体积变化。电性能测试发现,该材料的首次放电比容量为142.2 mA·h·g-1,50个循环后容量保持率达到90.5%,较未经APS修饰的磷酸锰锂/石墨烯材料有大幅提高。

关键词: 磷酸锰锂, 3-氨丙基三甲氧硅烷改性, 纳米材料, 复合材料, 电化学

Abstract:

A high performance LiMnPO4/graphene nanocomposite as cathode material for lithium-ion batteries was prepared via surface modification of 3-aminopropyltrimethoxysilane (APS) on LiMnPO4 nanoparticles and electrostatic self-assembly of positively charged APS-LiMnPO4 nanoparticles and negatively charged graphene oxide. Successful APS modification on LiMnPO4 was demonstrated by the existence of 3-aminopropyl and Si-O-C groups in FTIR spectra. LiMnPO4 nanoparticles (ca. 25 nm) were found uniformly distributed on the surface of graphene sheets. The intimate contact of LiMnPO4 nanoparticles with graphene conductive network allows achieving fast electron transfer between the active material and charge collector and accommodating volume expansion/contraction of LiMnPO4 nanoparticles during electric discharge/charge process. The nanocomposite cathode material could deliver an initial capacity of 142.2 mA·h·g-1 at 0.05 C and maintain 90.5% capacity after 50 cycles, which were significant better than no APS-modified counterpart.

Key words: lithium manganese phosphate, aminopropyltrimethoxysilane modification, nanomaterials, composites, electrochemistry

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